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Beginning Astronomy?
AnalogBoy asks: "I figure, with the diverse backgrounds offered here on
Slashdot, at least 1(,000) of you would have an astronomy background, in
some way, shape, or form. I've always had a passing interest in all things
space, in particular, i've always been captivated by whats 'out there'. I was
wondering if any of youse guys had suggestions on books, programs
(Windows or Unix), and especially GOOD telescopes (Sub-$500-range).
I've looked through Google, etc -
but I want a community opinion! "
Amateur astronomy is an excellent, and quite rewarding, hobby. I've been an amateur astronomer, albeit a serious one, for about 15 years or so. My recommendations for every new astronomer is the same:
Far too many new astronomers enter into the field by purchasing a poor department store telescope, or conversely, purchasing an expensive instrument far beyond their capabilities and interest. Taking the time to look at the sky with your naked eyes will serve you better if you become serious about astronomy, or if you decide it's just not for you. If you just have to purchase something, check out binocular astronomy. Orion has a wide range of good binoculars for astronomy. Binoculars have a wide, rich field of view, they're extremely portable, and they have uses OTHER than astronomy. The benefits are obvious:
Good binoculars for astronomy aren't big on power, so avoid getting a big 'X' rating. What you're looking for is aperture (remember, aperture is about light-collection capability; more aperture, brighter images) 10x30 is the smallest binocular you'll find that's useful for astronomy, but an 7x30 can also be fun. 10x50 (~US$200)is about the best all-around binocular for astronomy, but 10x70s (~$300) can be found for reasonable prices these days. Orion has several nice binoculars for good prices.
Buying a telescope is another animal. I strongly recommend learning as much as you can about telescopes before purchasing one (you might even decide to build your own). Check out a book called Star Ware for an excellent description of common astronomical instruments, including a full rundown on scopes. Additionally, I would recommend searching out your local astronomical club. Astronomy clubs are generally filled with interesting people with expensive scopes and lots of good advice. You'll learn more with a club than though any other venue, and you'll get a chance to peer through those sexy scopes your wallet burns to purchase...BEFORE you buy one and have to live with it.
If you actually purchase a scope, my own preferences lean toward the Dobsonian Newtonian. (A Newtonian reflector on a Dobson mount) These things are easy on the pocketbook, have enormous apertures, and really let the beginner learn the ropes of astronomy before becoming encumbered with the automatic push-a-button-see-a-star stuff that Meade wants to sell you. You'll find lots of good stuff at Orion in the range of $300 to $500 - their 6" Skyquest Dob is currently $349. Having owned the first version of this scope, the Deep Space Explorer, I recommend this scope wholeheartedly for a first scope. Buy this and spend the rest on eyepieces (a subject I shan't broach) for a really fun scope that will serve you for years. It's portable (sorta bulky, but portable), big, clean, and perfect to get your feet wet.
Feel free to contact me if you have questions. I have LOTS of opinions that I generally dole out for free. :) Have fun!
What'dya mean there's no BLINK tag!?
the field of view is broad enough that you can see the context of what you're looking at, to match with star charts. A good pair will set you back between $100-300. For best results, look for "long eye relief" and try to keep the ratio of the aperture to the power below 7 (e.g., 7x50 binocs have a ratio of 50/7, or just over 7). Binocs don't need to be polar-aligned, which is a pain in the a**, except on the new GPS-equipped scopes that are definitely too pricey for beginners. Also, check out Heavens-Above.
The best way of getting into astronomy is through your local club. There are several in the greater boston area so I imagine there must be a few where you are. Here is a link to one club listing
;-)).
:).
http://www.astromart.com/links.asp?c=1
Most clubs have observing places that you should visit on clear nights. Best way to make like-minded friends and get educated about equipment, etc (and to really find out if 'standing in one place in sub-freezing temperature for several hours in pitch dark' is your idea of fun
Once you get into it, you'll have more suggestions than you'll want and more equipment you'll want to purchase than your wallet can afford
PS: NH Astronomer Ed Ting has a great website reviewing telescopes http://www.scopereviews.com
Slashdot looks deep within my heart and assigns me a number based on the order in which I join
if you need something to help identify just what the heck you're looking at....
Try xephem
It's a part of debian and (used to be) red hat I know.... it's helped me to figure out what a particular bright object is at times.
Blech. Signatures.
The Meade Autostar telescopes are great for someone who is wanting to look at the cosmos but isn't sure where to look. You set it up, do some alignment, then select from thousands of different objects to look at. It will automatically locate to that object.
I react to only the most volatile substances.
For me there's only one set of books that, in addition to being better observing references than anything you'll find out there on CD, really capture what it is to love the night sky. Burnham's Celestial Handbook, published as three huge volumes in updated form in 1983 remains a true classic.
I hardly know where to begin in urging you to own these books. First of all don't be put off by their age. They may not be up to date on all the shiniest new astrophysics, but that's utterly unimportant compared to the huge number of treasures contained within them. The Celestial Handbook is an encyclopedic journey through the deep sky objects visible to an amateur telescope, organized alphabetically by constellation as a compilation of descriptions, observing notes, mythology, finder charts, photos, poetry, orbital diagrams, illustrations, light curves and tables.
If you feel like you've moved beyond the "Welcome to The Milky Way Galaxy" level of popular astronomical literature, these books will fill the gap in abundance. Each chapter starts off with a comprehensive list of objects to be seen in each constellation complete with notes about how they appear in amateur telescopes. After this there is page after page of detailed description about the most significant objects ranging from observing methods to mythology and ancient history. It is a tour guide for the observable universe, taking stops to examine a multitude of clusters, variable stars, supernova remnants, nebula, galaxies, and much more.
Insofar as the astronomy is dated, the effect really isn't very bad. Burnham was an astronomer at Lowell for many decades, and knew what he was on about. This issue is entirely outweighed by the masses of practical advice and genuine wonder to be found on just about every page. The observing experience of a lifetime went into these books.
Burnham was an astronomer by trade, and a poet by inclination. The Celestial Handbook makes this clear from beginning to end. I've owned my copy for almost twenty years now, and I'll never part with it.
First of all, as for binoculars (a very good idea, IMO) they are described by a two number 'code' such as 7x50 or 10x70, where the first number represents the magnification and the second the size of the 'input' lenses (in mm). Surprisingly to most newbies, it's the second number that matters the most. The challenge in seeing many astronomical objects is not in making them bigger, but in making them brighter (there are exceptions, of course).
There's a catch, in that if you make the objective lenses too big without increasing the magnification accordingly you end up throwing a wider beam of light at your eye than can actually fit through your iris. The width of this beam of light is called the 'exit pupil' and you can figure it by dividing the objective size (the second number) by the magnification (the first).
So, for many years, astronomers were advised to get binocs that had this measurement as close as possible to 7mm, that being about as large as young, healthy pupils can get. Any larger and you'd be wasting light, any smaller and your magnification would be higher than optimal, spreading all that light your glass worked so hard to gather over a larger area, and thus lowering the brightness of any one part.
Nowdays, however, more experienced binocular observers than I have determined that some magnification is a good thing to have, too. They suggest different binoculars will show roughly the same amount if the product of the two description numbers is the same. Check the link above for details. I'm not sure I'm convinced, but I know one way to satisfy both criteria- I'll buy binoculars with a traditional exit pupil, but the very biggest one's I can handle.
Which brings us to the other numbers that describe a pair of binoculars. The price, about which no more needs to be said (except perhaps the occasional 'yikes!' form the underpaid sysape), and the weight. Larger binoculars are, of course, heavier. Heavier binoculars are really hard to hold steady enough to see things with when looking up. 7x50's seem to be about the limit for hand holding by most people. Maybe 10X70's if you're Conan. Anything much beyond that and you'll be looking for a photographer's tripod, or a beanbag perched atop a wall, or any of the other myriad gadgets astronomers have cooked up to hold their binoculars steady.
Gee, what a saga. I hope it's usefull to someone. Think I'll ramble about scopes such in another post.
OK, Spent far too long explaining binoculars upthread, so I'll try to be more concise.
The Meade ETX telescopes mentioned above are what's known as go-to scopes. They use a computer, a pair of motors, and some reasonably simple initialization steps to find objects for you at at the push of a button, and to move the scope to keep it in view as the earth turns beneath your feet. This largely obviates the need to learn the sky, which is both good and bad. Good, because it gets you clear over the first hurdle upon which many beginners stumble. Bad because much of the money you've spent goes to pay for the computer and drives, rather than the optics, so the views you'll get will be somewhat poorer than comparably priced 'scopes of similar design.
The other extreme is the 'Dobsonian', elegantly planned scopes with bog-simple structures and mechanics, often mostly of cardboard and plywood, so that every available dime can be spent on the parts that actually harvest photons. Amazing views for the dollar, but you'll have to learn to find things yourself, and to keep nudging the scope along to keep them in view. Still, this is what most experienced amateurs of my acquaintance use and recommend, and I strongly suspect they're right.
What almost nobody seems to recommend anymore is the traditionally mounted small scope. These use a mechanical arrangement to allow the scope to follow objects across the sky, but they don't locate objects for you, and they have to be carefully aligned each time they're used if you want to take full advantage of the tracking. For certain applications, big, smooth, bulletproof (and often permanently installed) versions of these sorts of scope are perfect. But the one's you'll find in the price range in the article are typically flimsy, shaky, and really tough to use.
If you do decide to go whole hog and decide to both buy a telescope and start learning the sky, let me make two recommendations. The first is a 'zero-power finder', an inexpensive gadget like a head's up display for a telescope, or the red dot sight from a bb-gun (in fact, that's exactly what some of them are). It displays a glowing circle or dot that actually appears to be out there among the stars, at exactly the spot where the 'scope is pointed. There are other ways of finding things, but this is one of the easiest,
The other is a book called 'The Year Round Messier Marathon Field Guide' by Harvard Pennington. It shows maps for finding a hundred or so of the most popular observing targets (the Messier objects), such a way that slightly more experienced observers can find them all in one night (the 'Marathon'). The maps are marked up with simple geometrical constructions that make it clear that, for example, to find object a you should put the circle just about two thirds of the way along the line from stars b to c, maybe little skosh off in the direction of d. This was the book that finally got me over the hurdle from knowing how to find a handfull of things to knowing I can find whatever I want to badly enough, just by knowing how to read a star map in a certain way.
And even if the hobby turns out, in the end, not to be for you, let me recommend Sky and Telescope magazine. Observing's not everyone's cup of tea, but there's no better way for _anyone_ to keep up on the amazing discoveries that seem to be occurring almost weekly now than in S&T's clear and complete pages.
Finally, let me second (third, and fourth) the suggestion that you find and join your local astronomy club. There's a reason these thrive when most similar organizations are withering. All the info you can get from Slashdot is great, but it doesn't hold a candle to actually peering through other people's scopes before you choose your own, or asking navigation questions of someone who can stand beside you and point. Besides, nothing improves an amazing view like sharing it, and nothing can salvage a cloudy evening as well as an hour or two of coffee and astro-gab before calling it a night and heading home. Nope, not even Slash (though tonight, Slash is warmer)
HTH,
Chris