A friend suggested that I offer some advice on buying a telescope as a gift for a first-time astronomer. Well, the holidays are fast approaching, so I thought he might not be the only one who could use such advice. Thus my first-annual Telescope Buyer's Guide!

Assuming that a telescope gift must fit a modest budget, my first note is a caution: Do not buy a Wal-Mart telescope! Also beware of "tabletop telescopes," because your view is only as nice as the mount is stable. Remember, if you're using 32x magnification, that also multiplies any vibrations by 32 times. Anything that costs less than about $200 will give you more headaches than pleasure, and ruin the young astronomer's feelings about this wonderful activity.

So, a few basic guidelines.

Optical Design

If purchasing a refractor telescope (one that uses a lens for the primary objective on the business end, with the eyepiece at the opposite end), start looking at one with an objective lens at least 60mm diameter (about 2-1/2"), preferably 90mm. Here's a nice example, the Celestron Omni XLT 102ED (that's 102mm aperture, and better-than-average ED glass):

Click the image to see this telescope's web-store page.

Refractors are simple to use but, at the low-priced end, give false color due to the primary-lens design. Achromatic (and apochromatic) designs reduce (or even eliminate) this flaw... but at a cost. Because they have no central obstruction in their light-path as with a reflector, they provide brighter, sharper images at smaller objective sizes. Here is a fantastic apo refractor that is also very portable, the Explore Scientific 80mm f/6 ED APO:

Click the image to see this telescope's web-store page.

Reflectors vary a lot in design. The current most-popular style is the Schmidt-Cassegrain (SCT), which uses a mirror as primary in the rear of the tube that bounces off a small secondary mirror at the opposite end (which in turn shoots the light down the middle to your eyepiece at the rear), plus uses a sealed corrector lens at the business end (called the "aperture" - the diameter where light enters). A useful SCT starts at 90mm diameter (about 3-1/2") and can grow much larger. Here's a nice example at the small end of the spectrum, the Celestron NextStar 90:

Click the image to see this telescope's web-store page.

A similar 'scope is the Meade ETX90:

Click the image to see this telescope's web-store page.

Both are excellent starter instruments that easily track the sky and even have motorized, automatic go-to features, and are both affordable. I wouldn't go smaller than 90mm in an SCT. Get the nicest one you can afford! That's still portable, anyway; my 12" Meade LX90GPS weighs about 120 pounds, whereas an ETX90 only weighs about 20 counting the mount and everything. Here it is at sunset during the 2012 Venus transit of the Sun:

These are typically the easiest reflectors to use because they're so compact, and their shorter tubes make them even more manageable than a refractor. My 12" Meade LX90GPS (that's 304mm) would have been a nice university observatory instrument in the 1970s with its GPS locating and tracking and massive go-to database of astronomical objects, but now anyone willing to spend a few thousand bucks can buy one and enjoy hero views of the universe. The SCT optical design allows for cheaper mirror production, allowing you to get a lot more 'scope for the money.

You can find many other types of reflectors out there, but the Newtonian design (attributed to Sir Isaac) used to be the most popular, and provides the greatest light-gathering power for the dollar. It uses an open tube with a primary mirror opposite the open end, and a secondary mirror set at a 45° angle, which bounces the light into the eyepiece set at the top-side of the tube. Here's a nice example of a useful Orion AstroView 6" Newtonian reflector on a German equatorial mount:

Click the image to see this telescope's web-store page.

I wouldn't buy a telescope smaller than 6" aperture (152mm) in a Newtonian if you want the gift-recipient to enjoy it for more than a short time. Though a 4-1/2" Newtonian - a popular entry-level aperture - will provide lovely views of bright objects, it has very little resolving power (see below).

The Newtonian layout allows for the most-comfortable viewing positions and very stable mounts; to use a refractor or SCT at a comfortable viewing angle, you need to prop it up on a tall tripod, whereas a Newtonian can sit practically on the ground if the optical tube is long enough. On the other hand, it's also the least-compact design, requires occasional collimation to ensure the mirrors are aligned, and gets dirty inside faster. On the third hand, it's also the easiest to mount cheaply, because the heavy part sits low to the ground...


...thus was born the Dobsonian design, popularized by the sidewalk astronomer John Dobson in the 1970s. It looks like this Orion SkyQuest 6" Dobsonian (which uses the Newtonian optical design):

Click the image to see this telescope's web-store page.

Here's my other telescope, a present for publishing my first book. It's a Meade Lightbridge 16" Dobsonian reflector, with a Newtonian optical design. Because it's so large, instead of a solid tube it uses removable struts. This makes it lots lighter and WAY more portable - so much so that this giant can fit into a small car:

Click the image to see this telescope's web-store page.

On the other hand, it's a pretty large and heavy 'scope, not something I'd recommend for beginners. But if you have the space to store it and the strength to carry around 60-pound components (the base, or the rear mirror-box), a large Dobsonian like this is far less expensive for the optical performance than any other design. Almost anyone, however, can get a lifetime of pleasure out of a FAR smaller 10" or 12" Dobsonian, at a lot less cost, too.

My second telescope was this Crown Optics 6" f/8 (that means the focal length was 8 times the diameter of the mirror, making the tube 48" long) Newtonian reflector on a German equatorial mount with clock drive (which required a REALLY LONG extension cord to track the sky):

The German equatorial design is a bit more cumbersome and a lot more expensive than the Dobsonian box, but it allows for precise tracking of astronomical objects. These days, you can get one with battery-operated clock drives to counter the Earth's rotation and even GPS-precision go-to and tracking.

My first telescope was a very simple and completely manual Edmond Astroscan, a 4-1/2" rich-field (meaning "low power") Newtonian on a ball-and-socket mount:

Click the image to see this telescope's web-store page.

It was ultra-portable, foolproof to use, and nearly indestructible, but really limited in what it could reveal of the heavens. I quickly moved on to the Crown Optics 'scope, wanting more sky and something with a clock drive. It didn't have GPS or go-to, but did track the movement of the sky (countering Earth's rotation), so objects stayed centered in the eyepiece for long-time viewing, star parties with lots of people wanting to look, or astrophotography.

German equatorial mounts do require some setup, whereas the GPS-driven go-to instruments make setting up for a night's observing much simpler. Not nearly as simple as something like the Astroscan or a Dobsonian-style telescope, but way more useful for beginners and experts alike.

What You Can Expect to See

I would recommend one of the simpler, smaller instruments for a first-time astronomer: One of the 90mm or 120mm SCT designs is great for super portability and ease of use. A 6" or 8" Newtonian on an equatorial mount will show you every single nebula, star cluster, and galaxy in the Messier catalog, plus lots more. It'll also show you every planet in the Solar System, though Uranus, Neptune, and Pluto require a good eye to distinguish from stars in the eyepiece. Reflector designs cost a lot less than equivalent refractors.

Want to mostly view the planets, the Moon, and other bright objects? A really nice refractor will give you the best images, and you don't need much light-gathering power. More important is the focal length: In this case, longer is better. You want a focal-ratio of f/8 or longer. SCTs are almost all longer than that, as are low-priced refractors and many smaller Newtonians.

Want to get really nice views of those same objects, be able to magnify them more? Then you need a bigger aperture for better resolution.

Want to go deep-sky, walk across galactic spirals and float through vast nebulae? Go with the biggest reflector you can afford, and aim for shorter focal lengths. They call these "rich-field" instruments, because the field is wider and brighter.

Oh, and if you want to study the Sun, you need dedicated equipment. My SCT uses a big mirror over the open end, which blocks most of the light. This is the cheap route, and provides nice views of sunspots. Optimally, you'll get yourself a dedicated solar telescope if you want to spend a lot of time with the Sun; I just got the older (now out of production) double-stacked version of this one, the Coronado SolarMax 40mm Hydrogen-alpha solarscope:

Where a go-to instrument becomes worth the investment is hunting down dimmer and harder-to-identify objects. They can take a long time to find without a smart telescope pointing the way. On the other hand, like me you might enjoy the satisfaction of finding things yourself. If so, go crazy and get yourself a Dobsonian, which for the same money will reveal many more wonders of the deep sky. Typically, you get two or even three times the optics (diameter, thus light-gathering power) in a Dob than in an SCT or Newtonian, or many times that of a refractor.

A Note on "Power"

Cheapo supermarket telescopes will declare "600x POWER!" and such on the box. That is nonsense. Any 60mm refractor (or 120mm reflector) cannot give you that kind of magnification unless you're using it on a mountaintop, free of humidity and near the edge of the atmosphere. Useful magnifications are around 10x to 40x for most viewing; if you want to roam across the surface of the Moon, play around with different eyepieces to bring yourself "closer" (higher magnification, with worse resolution) or to show more of the Moon (almost no magnification at all, with sharp resolution). The Orion Nebula is stunning in my 12" telescope, but only visible at super-low magnifications.

Real telescope "power" comes from three things:

1) Its ability to gather a lot of light and squeeze it into your eye. The wider the diameter of the objective lens or mirror - the greater its surface area - the more light it gathers. For example, a smallish 70mm objective has 100 times the light-gathering power of your fully dilated eye!

2) Its ability to collect detail. The greater the diameter of the objective, the finer the telescope's resolving power (limited by atmospheric seeing). On any given night, a larger telescope will provide more-precise views of objects and reveal more hidden detail than a smaller one. Up to a point. Dust, humidity, clouds, and wind turbulence all affect this. Observatory-scale telescopes are greatly limited by these things, which is why they live high atop mountains and use fancy software to correct the photographs they take.

3) Its ability to reveal minute detail. Here's where magnification comes into play. Remember, most of the time you don't use much at all - I almost never hit 100x, and can seldom use that much under crappy Eastern Kansas skies. However, the longer your focal length (length of optical path - twice the length of the tube in an SCT, or about the length of the tube in a refractor or Newtonian), the more detail you can find by increasing your magnification. Shorter eyepiece focal lengths give you higher magnification (you divide it into the telescope's focal length to find the x), but you can seldom use an eyepiece shorter than 12mm. My favorite eyepiece is a 32mm monster with huge field of view, because its images are so sharp. So the bigger your primary, and the longer your f/ratio, the higher USEFUL magnification you can get from a USEFUL size eyepiece.

Okay, that one might have gotten a bit complicated, but you see my point. Don't use advertised magnifying power as a selling point. Your 8x binoculars are about right for 40mm objective lenses; more power, and you couldn't hold the image still, and it would be blurry. Low power is best for almost everything.


People often forget that the eyepiece is just as important as the objective lens or mirror. Get at least two; I'd recommend a mid-power (14mm - 18mm) and a low-power (24mm or larger) for starters. Three is optimal, ranging from 12mm to 40mm or larger. Really short focal-length eyepieces are a pain to use and don't provide much benefit. Really long focal-length eyepieces get pricey, because they use large lenses.

Most beginners (and those wearing glasses while using a telescope) need at least 15mm of eye relief to see the entire field. This means the image formed by the eyepiece is visible from up against it out to 15mm away. The longer, the better.

Aim to get the widest apparent field of view you can afford. Low-priced but nice Plossl designs typically provide 50° or so AFOV. Really nice multi-element designs can provide more than 100° AFOV, providing a sort of "spacewalk" feel.

Finally, make sure it's both fully coated and multicoated. This means all the lenses are coated on both sides against stray light, damage, and so forth. A nice foldable eyecup is handy. Oh, and get yourself an eyepatch to cover the eye you're not using, because squinting reduces your ability to see very well and is fatiguing.

This is the updated version of the eyepiece I use most of the time:

Click the image to see this eyepiece's web-store page.

It's a 24mm focal length, so medium power. It has an 82° AFOV, which is HUGE. Even though it has a complex lens system, it gives sharp images (probably because it's fully and multi-coated). And it's great for everyone to use with 17mm of eye relief.

Here's a nice assortment of nice eyepieces available through OPT, a place I buy stuff from a lot. Sort by price to see how little or much you can afford. Remember, it's tough to go wrong by buying REALLY NICE eyepieces, because that's what makes all the difference. A great telescope's images can be killed by cheap eyepieces, and an assortment really enhances the experience.

Final Recommendations

If you have a big budget and want to get a 'scope that'll last a lifetime, consider a 120mm apochromatic refractor, an 8" or 10" SCT, or a 10" or larger Dobsonian. These all cost about the same - let your goals be the guide!

Finally, remember that patience on the part of the user is the most-important element of a good night's observing. If your gift recipient is young or easily distracted, aim for easy to use, portable, and something that'll provide dramatic views.

In short, spend as much as your budget allows to get the greatest aperture, best mount, and nicest eyepiece assortment. Too small an aperture = dim, fuzzy views. Shaky or challenging-to-use mount = awful experience. Cheap eyepieces = nonexistent or crappy views. But if you go TOO crazy in size or weight, that can also kill portability.

Click the image to check out a star-party page.

I hope this helps!

mckitterick: Yes, this is one of my actual scooter helmets. RESPECT THE EMPIRE. (telescope Crown Optics)
( Feb. 18th, 2011 01:11 pm)

Today is Pluto Day! On February 18, 1930, Clyde Tombaugh (that's him, below) announced his discovery of Pluto.

Everyone knows that many people were disappointed by the decision to demote Pluto from "planet" to "dwarf planet" a few years ago. Especially Americans, because Percival Lowell (the astronomer whose calculations indicated that Pluto existed) and Clyde Tombaugh (who finally discovered it) were both Americans. Did do you know Tombaugh's full story? Here he is with his homemade telescope that he used to search for Pluto:

Click the image to see the KU Department of History story.

And here's Tombaugh's story, courtesy of the KU Department of History:

Not many undergraduates enter the University of Kansas having already achieved worldwide fame. And, to date, only one has enrolled at KU after discovering a planet. His name was Clyde Tombaugh, a 24-year-old amateur astronomer from Burdett, Kansas, who positively identified Pluto as the ninth planet in our solar system on February 18, 1930. The finding was the culmination of many years of scanning the night skies by numerous astronomers searching for what had been known as “Planet X,” an effort analogous to looking for a golf ball located 33 miles away.
full story under the cut )
So today let's celebrate Clyde Tombaugh and his discovery of the planet Pluto!

The headline says it all: Just last week, a 10-year-old Canadian girl discovered an extremely dim supernova in the galaxy UGC 3378 - also extremely dim - in the constellation Camelopardalis. Here it is:

Click the image to see the story on the Abbey Ridge Observatory website.

Very few people ever get to see a supernova, much less discover one. And now a young child has found one! Here's a charming BBC interview with Kathryn Gray, Supernova Girl:
behind the cut )

Move over, Clyde Tombaugh,
discoverer of the planet Pluto! (That's him to the right with his home-made telescope.)

Beautiful, clear day outside here in Lawrence, Kansas. Also frakkin' cold, with actual temps below zero Fahrenheit tonight, with wind chills in the negative teens. Oh, and half a foot of snow on the ground. Methinks I shall do no astronomy tonight.

Clear skies,
Years ago when I thought about what I'd do to as a present for publishing my first book, I wanted something that doesn't really interest me any more. So I've been thinking about it for a while and updated my desire to something that I would love, that I've wanted for a long time, and that's appropriate re: the book. A mondo-sized Dob!

Meet my new Meade Lightbridge 16" Dobsonian reflector. This is the simplest form of telescope to use: just point and shoot. No complicated computers that fail, no motors that fail, no nothing but the observer and the instrument and the sky. I imagine I'll eventually rig up a tracking system for easier view-sharing among friends, but as big as this is, its short focal ratio means magnification is only about half that of my GPS-powered 'scope (which is currently out of service, despite hours of effort in software and hardware troubleshooting), and thus images will remain in the field of view longer.

I've missed the lovely Orion 10" Dob that I sold when I bought my bells-and-whistles Schmidt-Cassegrain 'scope, but one doesn't just replace a telescope with one of the same size. And considering Dobs are much cheaper than SCTs, I decided to take the big leap up to 16 inches of light-gulping power! If you're a boat owner, you know what I mean, only it's two-inch-itis instead of two-foot-itis. On the practical side, it's about as big an instrument as I can carry around by myself - note that the truss-beams unscrew, and the tube lifts out of the base, making it really portable for its size.

EDIT: Oh, and I almost forgot to mention! Those of you who know me well are aware that I purchase almost nothing at full price. This 'scope is no exception - I got it for much off the retail price plus free shipping. The free shipping part is HUGE with something that weighs 150 pounds or so.

Snapped this shot a few minutes ago after I finished assembling it... can't wait to try it out later!

Next star party, y'all're invited.

To get away from compulsively checking poll results last night, I shut down the computer and went outside to do a little backyard astronomy. It was cold, but the sky was clear and the stars were calling.

(I should point out that my 12" Meade LS90GPS GPS telescope's drive is still dysfunctional due to a nuked hand controller. The one I purchased from eBay to replace it? Doesn't work with my particular model of drive, so I'll have to update the firmware in hopes that it might do me some good. So this means I was bouncing around the light-polluted Lawrence sky using only my Mark I Eyeball for object-identification. Happily, these objects are very simple to pick out among the stars.)

First up - and how couldn't I, what with it blazing as the brightest other than the Moon night-time object in the sky! - was Jupiter. I will never weary of its beauty and majesty, the drama of its bands and zones rushing past one another at hundreds of miles per hour, in their wake creating vortices larger than the entire planet Earth. As a kid who read too much Heinlein, my great dream was one day to explore the moons of Jupiter, to live in the realm of the Giant Planets, far from the Earth and all its attendant troubles. Can you imagine what it must be like to wake up, look out the window, and see something like this every day?

Click the image to see more of Jeff Bryant's astro-art.

Here's a video of Jupiter taken through a telescope like mine. He gets a little nicer views than one can see with the naked eye, but it's a good indication of what's possible to see with a backyard instrument:

Click the image to see more great astrophotos by Mike Salway.

Because it floated nearby, I next moved on to the Andromeda Galaxy. This is one of the very first astronomical objects I ever photographed (and developed the film!) through my Crown 6" f/8 Newtonian German-equatorial reflector when I was 13, using a Minolta XRT201 (I still remember!) 35mm film camera. Visually in a city's light pollution, one doesn't see much, but here's what you can capture with a CCD camera and a little patience:

Click the image to see more of Leo Taylor's astrophotos.

Visually, not terribly exciting, but let your imagination conjure up hundreds of millions of stars spiraling around a suprmassive black hole at the core; think of all the thousands or millions of planets harboring life... a galaxy is an island universe (click to see what Andromeda looks like through an observatory 'scope), everything that we'll ever likely see in person should we go to the stars. Our galaxy is every star in our sky, every nebula, every globular cluster, everything within millions of lightyears. That's a galaxy. So even if it's just a smeary fuzz in the eyepiece, you know what you're seeing, and that makes all the difference.

Finally I pointed the 'scope over the roof of my house, through some tree branches, to catch a glimpse of the Orion Nebula. Not the optimal viewing scenario, so I didn't expect much, but figured I'd catch my favorite deep-sky object while it floated between some naked branches, then head inside. What I didn't expect was the phenomenal, dramatic, awe-inspiring view my 78°-field-of-view, 17mm eyepiece provided. Holy emission and absorption nebula, Batman!

Click the image to see more great astrophotos by Mike Salway.

It was so beautiful that my breath caught; it was as if I had never seen this nebula through a telescope before. In the foreground, dark lanes of dust and gas billow, partially obscuring the bright background nebulosity lit by the Trapezium cluster (those four bright stars at the core of the nebula). I'm sure I expressed my awe verbally. Just wow. I swapped out my eypiece for an 82°-field-of-view, 33mm unit in order to catch the companion cluster and nebula (below in the photo above), but reducing magnification hid some of the details, so next I installed my f/6.3 focal reducer into the back of the 'scope and re-installed the 33mm eyepiece... but by now Orion had passed into the trees. Time to call it a night.

So I went from disappointed and disgusted to filled with delight. This is why I love astronomy. When I need a lift, when I need to know there's something beautiful in the universe, when I need to feel that good ol' sensawunda, the sky never lets me down.

Around 1:00am tonight, I took out the telescope to view Jupiter, which is about as close as it'll be until 2022. First the bad news: My 'scope's hand controller stopped working, so I couldn't align it, use the clock drive, or anything else. Better news: I can still sight and capture objects without all those modern doohickeys, even if I've been spoiled by a robotic GPS system. Best news: Without realizing tonight was a big deal, I happened to catch Io's transit across the disk of Jupiter. Wow, whatta sight! Looked a lot like this tonight:

Click the image to see more Jupiter photos by AztecastroMcJ on Flickr.

It was a bit of a pain to adjust both altitude and azimuth every few seconds to keep Jupiter and its mini planetary system in the eyepiece's field of view, but I pulled up a stool and just nudged it as needed. Just like the old days, before battery-powered, satellite-sensing, cylon-scopes took over.

Right now, Jupiter is so darned bright that I used filters to see if one might improve the view (partially by dimming it, partially by filtering out too-bright colors), and indeed the Mars filter brought out a huge variety of textures and colors in Jupiter's stormy atmosphere. But I ended up preferring the warm, natural colors of my favorite planet sans filter in a William Optics 33mm Swan mega-eyepiece (about the size of a small telescope). The Baader Planetarium 17mm Hyperion eyepiece provided a pretty kick-ass view at twice the magnification, but having to adjust every second or three inspired me to use the big, low-power unit instead.

I couldn't identify the high-contrast dark spot on the face of Jupiter - alien vessel? asteroid strike? - but figured it must be one of its Galilean satellites. When I got back inside, a quick search found this super-neat applet to find the position of Jupter's moons, and discovered I was, indeed, right - it was Io. To see the Jovian system as I saw it during the transit, set the time to 06:30 (when I first captured Jupiter) through 07:00 (when Jupiter started grazing the treetops in my back yard) at -5 time offset. What an AWESOME tool! Want to know which moons you're seeing on a particular night, or plan your viewing for during an occultation or transit? Check out this page first.

Okay, now the super-excited is wearing off a little and the sleepy is hitting. G'night, and clear skies!

First off, this could turn out to be one of the most important discoveries of all time: Astronomers have directly observed something huge (about four times the width of Earth's orbit) eclipsing another star, Epsilon Aurigae. After astronomers discovered some 200 years ago that it dims every 27 years, they postulated it was an eclipsing-binary star: two stars orbiting one another - in this case, a smaller one orbiting Epsilon Aurigae every 27 years - with their orbits on a direct line toward us, thus one star eclipses the other from our point of view.

But an odd detail threw a monkey-wrench into the theory: During the eclipse, the star briefly brightens. WTF? The theory was modified to include a cloud of gas and dust orbiting the primary star, perhaps surrounding the secondary (blue) star. What would that look like? Here's an artist's impression of this amazing and unique binary-star system. Note That the secondary star, young and blue, is mysteriously shrouded in a clinging disk of gas and dust, something we have not observed anywhere else in the universe:

Click the image to see the Wiki article about Epsilon Aurigae.

The solar winds and radiation pressure from a star are more than enough to blast such a cloud into smithereens in short order, yet here it is, 200 years later, still intact. This explanation seems pretty unlikely, but the observations make us come up with some pretty wacky explanations, like a shrouded star orbiting another star, or an invisible star (no, really, that was one hypothesis), or a black hole with an accretion disk. Here, check out this just-released video of the eclipse, showing the mysterious eclipse in action:

What's that look like to you? I have my own hypothesis, no less crazy than the currently operating ones. If you're an SF reader, you've probably heard of ringworlds, Dyson spheres, and other megastructures like these:

Halo players will recognize this one, also fans of Banks' Culture series.

Artist's impression of the megastructure from Niven's Ringworld.

Does it not make more sense that we're looking at an alien artifact, some kind of super-massive structure (such as a ringworld under construction, the relic of a long-destroyed megastructure, or a vast colony ship) rather than some mysterious form of binary system? Why not! Can't wait to learn more about this.

EDIT: Matt submits another potential Dyson Sphere, the "Cynus Bubble":

Click the image to see the story.

In related news, scientists have discovered multicellular life-forms on Earth that do not need oxygen to survive. This opens up opportunity for life on worlds we previously would have considered to be barren and lifeless. Of course, science fiction has given us oxygen-free aliens for decades, but now we have some scientific evidence to back it up. Like this little guy:

Click the image to see the BBC News story.

Once again I note that we live in amazing times!

A couple of days ago, I managed to get outside and do a bit of backyard astronomy. Happily, my GPS-aligned telescope no longer thinks that this is the nearest city (as it did until I discovered this little setting buried deep within its programming):

Thusly corrected in time and space, my loyal guide to the heavens has sat mostly unused since fall due to, well, winter being frakkin' nasty this year. I've been anxious to roam the skies again, and fate served up a reasonably warm evening on Friday: below freezing, yes, but not single-digit frigid. I headed outside at about 11:30pm, set up the 'scope in the backyard on frozen ground near the fire-pit, had it self-align (without needing much input from me), and then pointed that 12" mirror at Mars. The face it had toward Earth was exactly this, though a bit less sharp and with more ice cap:

Wowza. Having just acquired a set of planetary filters on a neat selector-wheel, I tried viewing Mars in red, green, blue, and yellow (blocks out other colors), and then with a special "Mars filter" designed to block all frequencies of light except those that best reveal surface features. As you can imagine, that one showed the most, including the large dark areas in the University of Maine photo above. While viewing, I noticed a huge gap in my eyepiece selection: the 21mm Plossl is too low-power to show Mars large enough to see the features very well, but my next-shortest focal-length eyepiece is an antique 8mm Edmund Scientific unit I bought when I was 13 years old for my charming 4" Astroscan (which I had bought when I was 12 using saved-up dish-washing money):

As you can imagine, image quality with this old (orthoscopic?) eyepiece is not great. I also have a 5.1mm Orion ED eyepiece, which - when coupled with my high-power telescope - offers just way too much magnification to show much in the way of decent images. I tried using a 3x Barlow lens with my 25mm Plossl, which gave the best views, though all the extra glass in the way washed out the sharpness. *sigh* So tonight I just ordered myself a nice, medium-power eyepiece (big sale at Orion!) and look forward to seeing the planets both bigger and sharper than I can now.

Next I slewed over to Saturn, almost overhead at 1:30am. Its rings are still almost edge-on as in this (not great) photo I took last year:

Only with a big shadow beneath them across the planet's face and Titan like a diamond pinprick nearby. Wowness! At this point, because Mars looks so big and dramatic at its close approach and Saturn is always just amazing, I tried taking photos with my Meade DS-III CCD camera. After much setting-up on a couple of lawn chairs (one for the laptop, one for me to operate everything), I discovered that the camera wasn't sending any images. Hmm. I fooled around with it for a while, restarted the computer, but nothing. Hmm. I considered dragging out a borrowed DSLR camera, but figured that 0'dark-early in the morning when one's fingers were starting to freeze off was not the best time to try something new.

So I shut down the photographic equipment and decided to end the night with Ol' Faithful, our lovely Moon. Its phase was pretty close to that in this photo I took last year:

When viewing something as huge as the Moon, low-power eyepieces are best, so I went for my biggest, a 34mm wide-field unit. Because it was almost full - but not quite - the terminator (the unlit edge, not the robot) offered dramatic contrast and shadows. In fact, one crater was lit in such a way that only a thin band of its wall was visible, half the curve hidden in pure blackness (no atmosphere to scatter light), seeminly hovering above the surface of the Moon. How I wish I could have taken a photograph to show you!

About then, I could hardly move my fingers to focus the telescope and called it a night. Got everything put away and went inside at just before 3:00am. Can't wait for the next opportunity! And I'll be sure to take some photos next time.

Hooray! I've finally figured out the over-contrast issue with my CCD astro-camera (short story: don't expect the manual to help; seek info on the Web), and figured out how to get my telescope to quickly identify an object and (sort of) track it, and viola! I have my first photograph of Jupiter! Taken by me!

Photo by Chris McKitterick using Meade 12" SCT, prime focus, DSI-III CCD camera.

Notice the Great Red Spot, about in the center-bottom? Awesome! It's wider than two Earths laid side-by-side. Those varying-color bands are actually strips of atmosphere moving at hundreds of miles per hour in opposite directions. The bands' different colors come from the composition of gases in the clouds of the varying regions.

Next: Figure out how to get the telescope to properly track an object so I can combine images into a higher-res photo. The naked-eye view is much nicer than this shot, so it'll just take some practice.

Hope you like it!

Howdy! I took today's shots late last night, when Saturn was directly overhead and the Moon was a bit to its right. My goal was to photograph Saturn, but that didn't work out very well:

This shot does show that the rings are pretty much edge-on right now, and that's interesting, but the camera just doesn't know what to do with really bright objects. To the naked eye, I could differentiate the ring from the planet - like a very slight shadow on the globe below - and what appeared to be four of its moons. Titan was obvious and I thought for sure it would show up in the image, but its parent planet was so bright that it overwhelmed the light from its little coterie of worlds. I'll continue to play with this.

Oh, and I should mention: WINDY! Most shots were blurry due to wind. I really want an observatory ;-)

To take successful shots of the Moon, I used a masking technique to reduce the amount of light entering the telescope. My high-tech method included standing beside the tube and slowly moving my arm in front of the aperture to block up to about half the light. This took advantage of the 'scope's full resolution power (full width of the mirror) without its full light-gathering power. Shots I took without masking showed bright areas as washed-out and pixelated. The best shots seemed to be when I blocked most of the light by placing my arm (in a thick jacket) across the widest part of the aperture. Oh, and I was also using a polarizing filter set at its darkest (about 40%). This should give you a little idea of just how damned bright is the Moon through a 12" telescope. It's also a bit too long-focus to take full shots of the Moon: Note that only a small portion of the world shows up in each shot. That's without any magnification (no eyepiece), directly into the camera, and with the focal length shortened by 37% from using an f/6.3 focal reducer. Okay, the shots:

In this first photo, notice the two bright craters with what looks like stripes spreading out from them. Those are called rays, detritus from the impacts that created those craters. Also notice that some craters are dark and some are light; this has to do with what was going on geologically on the Moon at the time those craters formed. Really dark ones show melted rock that filled the craters from deep below, and bright ones are filled with Lunar dust. Even more dramatic are the vast maria, the huge dark areas rimmed by brighter walls. Yes, those are the remnants of massive craters that almost destroyed the world back in its earliest days.

click for more shots )

In honor of the International Year of Astronomy, I hereby vow to post my Astro-Image of the Day at least three times a week, every day if possible! This is in keeping with the IYoA org's mission:

"The International Year of Astronomy 2009 is a global effort initiated by the International Astronomical Union (IAU) and UNESCO to help the citizens of the world rediscover their place in the Universe through the day- and night-time sky, and thereby engage a personal sense of wonder and discovery."

Sense of wonder. Discovery. For me, this is what astronomy is all about, and it's why I find beautiful or exciting space photos (and occasionally try to take them myself) and share them with you. I want to share my excitement about astronomy because it's my first love, a place and an activity and one of the very few means to find peace and sense the numinous. Astronomy is not just the cool equipment (though I love the devices we use to reveal the secrets of the universe!), and it's not just the gorgeous objects hidden behind the veil of light and sky (though it wouldn't be all these things if not for the planets and moons and stars and nebulae and galaxies and so forth); for me, what astronomy is at its heart is the search and discovery and the glorious mix of emotions one feels when first discovering some grand and gorgeous jewel hidden in the sky, or when sensing the vast scale of the universe and our place in it, or when so lost in the act of observing that one feels like an explorer, or returning to the comfort of a familiar beauty often visited, or any of those moments of quiet joy that astronomy brings.

Two things prevent most people from enjoying these things: proper equipment and light pollution. Check out the various dark-sky organizations for information about how you can help eliminate the light that hides most of the faint objects.

If you're interested in the equipment for astronomy, I'm happy to offer advice for telescope buying and so forth. A couple of quick suggestions: For a refractor (lens-type telescope), don't get anything that's smaller than 60mm; for a reflector (mirror-type), you want something larger than 4" - and in both cases, if it costs less than $200 or you can get it at Wal-Mart, it's probably crap and will only frustrate you. Magnification is pretty much unimportant; objective and eyepiece quality and light-gathering power are key to a usable 'scope. Your best bet is to get the best instrument you can afford or just do your astronomy via the internet. A quality pair of binoculars is also a great gateway to the universe, especially for viewing big things like the Milky Way.

But basically, unless you know you're into astronomy, I suggest the best way to get started is to simply seek out dark skies with friends, take along a decent sky map, set up lounge chairs, and maybe scan the skies with your binoculars. If you feel the journey is more important than seeking things, you'll love it.

Last night was clear once more, and Venus - so bright and high in the sky - was a tempting target, and I wanted to test the setup changes I made to my telescope's drive. So: a new astrophoto!

Keep an eye on the western sky just after sunset for the next few weeks, because Venus rises to its greatest evening elongation - until 2017! - on January 14. This means it'll stand the highest in the sky on that night, and it'll be approximately quarter-phase. This is because, at its highest or greatest elongation, it stands at its farthest from the Sun from the perspective of the Earth. When it's closest to Earth, it's between us and the Sun, so then it's at a phase comparable to "new Moon." When very near the Sun from our POV, it's nearly full. In my photo, notice how the planet is a bit larger than quarter phase: It's waning gibbous phase right now.

So even though Venus goes through phases like our Moon, it's for very different reasons: For example, the Moon is full when on the opposite side of the Sun from the Earth. Similarly, Venus is in waxing phase in the morning sky and waning phase in the evening sky.

Optics details )

Here's how Venus would photograph if one had a telescope in orbit around the planet (a bit fuller, though):

Click the image to see the wiki article.

Still loving this whole digital-astrophotography thing.


Here's my newest astrophoto taken with the Meade telescope. I took this one as part of a test to see if the changes I made to the drive's setup yesterday helped tracking. Unfortunately, soon after setting up the telescope and assorted electronics, I discovered that there's no Sun setting in the system. WTF? So I had to manually set it up using a compass and level. Seriously. Anyhow, the results don't really tell me much, because part of today's manual setup required pointing to two stars that I couldn't see, what with it being daytime and all. *sigh*

So I got results similar to the Moon shots: Once again, the drive didn't track correctly. Even more disappointing is that, through the eyepiece, I couldn't spot any sunspots or any other details, just a big, over-bright orb of Sun-ness.

(At this point you might be wondering why I'm not blind. Of course I used a full-aperture solar filter! Never point optics at the Sun without a true solar filter that covers all of the primary end of the instrument.)

Still, I thought it might be fun to once again image the movement and make an animated GIF to offer y'all what feels like a flight over the Moon! Here's a still from the animated GIF (which you can see under the cut):

During image processing on my computer is where I got really excited. Notice the detail you can see beyond the bright surface of the Sun: That's the Sun's corona. Wowee! I photographed something I didn't even realize you could see without the Moon eclipsing the Sun. Suddenly I'm really happy with the shots! If we could reduce magnification a bit more or gain a wider field of view, my photo would look something like this, taken in France during a total solar eclipse in 1999:

Click the image to see the story.

Optics details )... to produce this flight to our nearest star:

Click to see the animated version! )

I'm loving this whole digital-astrophotography thing.


mckitterick: Yes, this is one of my actual scooter helmets. RESPECT THE EMPIRE. (Meade telescope)
( Jan. 7th, 2009 09:40 am)
Okay, now I feel like a dummy. Y'know how I mentioned in yesterday's astrophoto post that I was having troubles with my telescope's tracking? Well, I think I might have figured it out.

I studied the rather thick manual and discovered the Setup menu and its special features. Seems that the mount thought the time was PM, not AM - and it was also an hour off, thinking that we were in Daylight Savings Time. That's 13 hours off. Plus, for some freakish reason, it was also two days off, thinking it was the 5th, while today is the 7th. Odd, these things, for a GPS-powered instrument. (I also input some info such as my name and address.)

Once again proving the value of reading the manual cover-to-cover.

We'll see how it works during my next astrophoto session!

I made this animated GIF from a series of astro-photos I took using my Meade 12" LX90 GPS telescope and a Meade DSI-III astro-imager, then reduced the image size and pumped them through an animated-.gif maker (free version, hence the silly "Trial Version!!" banner).

Because my telescope's drive appears to think it's on the Earth's Southern Hemisphere, so the drive isn't tracking correctly. Ironically, even though this makes taking astrophotos a pain in the buttocks, the movement inspired me to make this into a single GIF. Feels like a flight over the Moon!

EDIT: Optics details: This image was taken at prime focus (no eyepiece) through an f/6.3 focal reducer, resulting in a focal length of 76.8" or 1951mm. Without the reducer, this telescope is an f/10, giving it a focal length of 120", which would increase magnification even more (at f/6.3, the Moon more than fills the field of view at prime focus).

Images are less than 1 second each; not sure exactly how long (I'll pay closer attention next time - was distracted by the combined image looking so blurry), nor of the interval between them. Say, 1/10 second each with an interval of a few seconds?

Next time I'll also use a polarizing filter to help reduce the over-bright areas, and adjusting the clock drive will allow me to combine images for greater sharpness. Here's a still from the animated GIF (under the cut):

animated version )


Can you guess what this is?

No, it's not an astro image.

clicky for answer )The Deep Sky Imager is a royal PITA to focus, so it's best to set up the focus during the day on motionless subjects using an eyepiece and locking ring (making them "parfocal") and then finding the camera's focus. My first attempt with the Moon led to frustration, as the camera's focus is about 15mm different than the eyepiece that the manufacturer recommends using to focus an object.

In case you haven't seen it yet, here's the telescope:

And here's the astro-camera (a replacement for the broken one the retailer sent last winter):

Now I'll be able to image astro-things much more simply... hopefully starting tonight! Then you'll get fresh amateur astro-images on a regular basis. Hoo-boy, amateur photos! I bet you're thinking ;-)

Tonight I finally was able to try out my new Meade 12" f/10 LX90GPS Schmidt-Cassegrain telescope that arrived a few days ago. This was a present to myself, paid for by selling astro-related things (and, hopefully, the money returned to me from USBank giving it to someone else...). Because it's been cloudy, foggy, or raining, today was my first chance to try it out.

I've never had a go-to 'scope before, and I've always been leery of such. But I've recently returned to astrophotography, and this one really improves that with its built-in GPS setup! With other types of mounts, one has to align on the North Star, then offset the mount just a bit to find true north. Then there are the leveling issues, blah blah blah... basically, if you want to take astrophotos, you end up spending a good portion of the night just aligning your 'scope. With a GPS-powered mount, all you do is turn on the 'scope, and it automatically identifies where it is in the world (latitude), then what time it is, then adjusts for level (or not), then points at a couple of stars. All you have to do is center the stars in the eyepiece and give the instrument a little pat on the head, and then you're ready to go!

First up was Mars. Right now, the Red Planet is at its closest approach in many years, so get out there and take a look! (Click here to see where and how to find it.) It's almost exactly overhead by midnight, and when the Moon is full this month, they'll be within a couple of degrees of each other in the sky. Pretty dramatic. You'll recognize it by its intense brightness and dramatic red color, and you'll be able to distinguish it from the other stars (such as Betelgeuse, also red) because it won't "blink" like stars do: Unlike stars that are essentially point objects - that is, you can't really magnify their size, so they might as well be single points - planets are made up of many points of light that form a disk. What makes stars blink is that atmospheric disturbance can literally turn off the light from a star, but all that'll happen to a planet's disk is that it might get a little bit darker.

Anyway, I made for Mars first. Using the very nice 26mm Plossl eyepiece that came with the telescope, Mars had sharply defined dark and light regions, not unlike the user-icon for this post. I've never seen it so gorgeous before in any telescope! It looked a bit small, though, so I tried an assortment of other oculars: 21mm TeleVue Plossl (about the same, but without the rubber eyeguard, I needed to shield my face from the neighbor's back-yard light... did I mention that I was observing in my back yard? *g*), 15mm eyepieces in a bino-viewer (I'm growing more and more unenthusiastic with bino-viewing, probably due to having astigmatism; anyone looking to buy a wonderful bino-viewer with two sets of eyepieces?), 5.1mm Orion ED (very large disk, but the magnification was a bit high for the night's increasing fog), back to the 26mm with a 3x Barlow (nicer than the other eyepieces, but I'm afraid that I must have exhaled on the Barlow, for it had a big fuzzy halo around the planet), and finally back to just the 26mm. The edges of the disk appeared to be a bit bluer, as if the Martian atmosphere were having a similar effect as does our own. Wow! I'd never seen that before! What a difference a couple of inches makes with a telescope.

Excited about the gorgeous view and wanting to share with y'all, I plugged my CCD imager into the USB port on my laptop (yes, I was surrounded by a maze of cables) and slipped it into the telescope's focuser tube. The laptop display showed Mars in real-time, refreshing about every second or two, growing sharper with each little twist of the focuser. Finally, I had it just about perfectly focused when the image went all snowy and then vanished. I unplugged the imager from the computer, plugged it back in - nothing. Then I shut down the software and re-started it - again, nothing. Harumph. After fiddling for a while, I gave up, shut down that equipment, and just returned to using my own biological imager. I watched Mars for another 20 minutes or so, noticing that it was growing hazier as time went on.

What's this? I wondered. I shone my little red-filmed pocket light - something I've used for astronomy since junior high - on the corrector plate at the "mouth" of the telescope and discovered that it was pretty much glazed over with frozen fog. Damn weather! Oh, did I mention that it's about 22 degrees F here in Kansas tonight? And foggy.

Not wanting to give up so early, I told the telescope to show me the Moon. Wow. A 12" f/10 set of optics seem to reveal about twice as many craters as I've ever seen... and this through a fine layer of frozen fog! Then I peeked at the Pleiades (not really visible with the Moon out and the fog), then Saturn (oops! Behind the house), then the Great Nebula in Orion (M42 - as WOW as ever, even in these conditions), and finally back to Mars, which seemed to improve with a bit of ice filtering its brightness.

Satisfied and freezing my heiny off, I shut down and put everything away.

I like my new telescope very much and look forward to nicer conditions in which to use it. And I'll be working on my CCD camera so I can show you some images, too!

I just finished editing these photos that I took all by myself with my new CCD camera and [livejournal.com profile] tmseay's Celestron 8" SCT telescope with clock drive! These are the first astrophotos that I've taken in years... well, more accurately, in decades! And my first digital astro-photos ever. I'm so excited. They're not great, but I'm only just learning how to use the camera. Plus, I didn't spend the time necessary to properly align the telescope for long exposures.

Okay, onto the photos. This first one gives a good idea of what you would see through a telescope with your naked eye (only it's actually prettier in person - odd for astro-images!):

Comet 17P/Holmes photo by Chris McKitterick, 4:17am US Central time, November 6, 2007.
Equipment: Celestron 8" Schmidt-Cassegrain at prime-focus using Meade Deep Sky Imager CCD camera; 15-second exposure.

With your naked eye, what you see looks much like a jellyfish without tentacles: Very smooth curve on the left side swooping around to the "back" (bottom-right), where it gets diffuse - the starts of a tail, methinks! Anyhow, the jellyfish has a sort of bubble-within-a-bubble shape, the outer bubble not quite as bright as the inner, so you can see it glowing within. At the core blazes the comet, itself, very bright in this image (not quite as much with the unaided eyeball).

I watched it with my Orion XT10" Dobsonian reflector, as well, and found that its short F/ratio (F/4.7 vs. the Celestron's F/10) liked a 15mm eyepiece best. The view through that 'scope was just amazing, with the shells much more contrasty. But without a clock-drive, I simply wouldn't be able to take a photo (the Earth spins too fast, magnified by the 'scope's magnification). I can't tell you how much I'm now looking forward to when my new Meade 12" SCT with GPS precision drive! arrives in a month or so, because then I'll be able to take super-long exposures! Ooh, I'm getting so excited!

I also took a few more photos of various objects including Mars and the Orion Nebula, but they didn't turn out very well. That clock-drive precision-issue again. It was such a geeky experience to be sitting outside with two chairs - one for the laptop and one for me - with USB cable coiling up from the laptop to the CCD camera and extension cord running from the 'scope's base all the way to a plug on the back of the house. I sat there looking at my computer screen (dimmed way down, of course), adjusting the image up-down and side-to-side in real-time while setting exposure (and having to wait that many seconds to see if the image was going to turn out) and centering the object and so on... lots to learn! The setup looks a lot like this, only with an orange telescope:

I began my education by using Mars because it was so bright that I could use Live mode rather than waiting for an exposure to show up. But it was so much fun, despite the 20°F (with wind chill) weather. Oh, and my fingers only now have warmed up; at some point not long after these shots, my fingers could no longer accurately type on the keyboard because they had lost all feeling (ever tried typing on a laptop while wearing gloves?).

Here's another goofed-up shot that I think looks cool. Same comet! Wacky results from a beginner with a CCD camera and too many photo-options!

Comet 17P/Holmes photo by Chris McKitterick, 4:21am US Central time, November 6, 2007.
Equipment: Celestron 8" Schmidt-Cassegrain at prime-focus using Meade Deep Sky Imager CCD camera; exposure unknown!

Oh, and here's where you can find the comet right now. It's really easy to find with your naked eye any time, say, an hour or two after sunset to very late in the night (obviously). The comet is as bright as the two nearest stars in Perseus, and more diffuse. In a binocular or low-power 'scope (like the finders on mine), it's clearly a ball of gas and dust rather than a star):

Click the image to see the story.

PS: Mars looks gorgeous right now! It's the brightest thing in the sky, and using my 10" telescope with a dash of patience, I caught glimpses of dark surface detail every so often. Oh, and it's in almost-full gibbous phase.

More photos as I take 'em!

I couldn't sleep, so I got up around 6:00am to do a little early morning astronomy. I used to do this regularly when I was a kid, turn on my alarm to wake me at 2:00am or so, when the sky is at its darkest and most house lights are off.

I peered outside and saw Venus blazing so brightly; she drew me outside - even in the 36° weather - with my telescope:

Click the image to learn more about Venus.

Since I was outside, I also took a look at Saturn:

Click the image to see more Saturn photos.

The sky was so dark and high-contrast that I could see the Orion Nebula with my naked eyes. Turned my 'scope to it, anyway:

Click the image to see the source page.

Of course, one can't miss the Pleiades Cluster when it's up (I love this shot with a comet blasting past):

Click the image to see the story.

As I was finding the Pleiades, I saw a star just as bright as the others in the sky, but moving fast. I quickly grabbed my little 'scope and tracked it for about 20° across the sky. So cool! That was the International Space Station whizzing by overhead, replete with our astronauts:

Click the image to see the story and to find the ISS in your sky.

And of course the Moon was up, too, third-quarter and waning. Even so, I could see so many more stars than usual. It's so beautiful this time of the morning, so dark-sky! I suspect part of it is that my pupils were about as dilated as possible after hours of sleep, but also most of the city lights were out, what with most people sleeping.

Must try this again some time. EDIT: Okay, now I'm dead-tired. Going back to bed for a bit. G'day.

When's the last time you had a night-sky view like this?

Click the image to see the story.

True, you can't see color like that with your naked eye, and the nebulae are tougher to see without a time exposure, but the naked-eye view of the portion of Milky Way that we can see from Earth is still spectacular.

When I was a boy living in western Minnesota, on Moon-less nights I could see a sky like this by simply walking a half-mile from our house, which stood about a mile from the nearby small town. We lived in a little valley beside the highway, half-way between the golf course about 500 feet vertically uphill (thus the half-mile walk up) and the lake about 1000 feet of walking downhill. I often dragged my Crown Optics 6" telescope up that hill to the wide, dark skies visible from the golf course.

PS: OMG - I did a quick search and found the original 1982 advertisement for my first serious telescope! I bought it with dishwashing money, plus a 35mm camera, an assortment of eyepieces and other accessories, and a big guide-scope just like on the "Research Series" telescopes. Check it out! )

Interesting to be reminded that it was a Meade Optics brand, and my next telescope is also a Meade Optics instrument... more on that when it arrives. I plan to start uploading my own Astro-image of the day in the next couple of months after getting used to the free CCD camera included with the purchase. And, because [livejournal.com profile] tmseay is now storing his Celestron 8" SCT at my place, I plan to organize some mini-star-parties in the coming months, taking advantage of the dark skies south of town.

That was a fun trip down astronomical memory lane. And if you've never seen the Milky Way in all its glory, get out to some dark skies sometime and just lie back looking up. Bring a binocular and slowly scan through the clouds of gas, dust, and stars that leap out of the eyepieces like fireworks. It's glorious.



RSS Atom

Most Popular Tags

Powered by Dreamwidth Studios

Style Credit

Expand Cut Tags

No cut tags