Observing Near Home
[October 21, 2000] I was just reviewing my observing log last weekend. Of 364 observing sessions in the last 30 months, approximately 80% were around home. 9% were less than a half hour drive away (mostly Montebello), an additional 9% were about an hour's drive (Henry Coe, Pacheco, Fremont Peak, Lick observatory), and only 1 to 2% of sessions were at darker sites located a couple hours or more away (Lassen, Lake San Antonio, Fiddletown).
Although I prefer observing at a dark site, constraints of time, and work, and kids, and the moon and weather, limit the times that is possible to 2 or 3 sessions a month. Fortunately double stars, bright open clusters, planets, and the battered surface of the moon all make beautiful targets near home.
Here are a few of the resources I have found useful for planning observing projects in brighter skies.
Double stars look great anywhere.
1) The astronomical league has a 100 doubles list that's a reasonable place to start (http://www.astroleague.org/al/obsclubs/dblstar/dblstar1.html).
2) Sissy Haas periodically publishes double star hops for particular constellations in Sky and Telescope. Her enthusiasm for doubles shines through in her writing. I also enjoy the range of targets, colors, and brightness contrast that she usually includes in her lists. The constellation approach also means that each article could serve as the basis of observing sessions at a particular time of year. See:
"Double Stars off Mizar," May 00
"Double stars of Cepheus," Sep. 98
"Gems of the Desert," April 98
"The Extraordinary Doubles of Bootes," June 96
"Wide Doubles in Capricornus," Oct. 95
"Double Jewels in Cancer," Mar. 95
"Double Gems in Pisces," Nov. 94
"Jewels in Lynx," April 1994
3) The "33 Doubles in Orion" project was an interesting constellation-based project I went through in a couple of sessions last January. Large range of star colors and distances, many of which took me to parts of the constellation I had never explored before. Most of the doubles were relatively easy. However 42 Orionis required attempts on a couple of different nights before seeing conditions were good enough to split the close dimmer secondary. This project was described in the February 2000 issue of Sky and Tel and maps and charts are also available online. (http://whuyss.tripod.com/Orion/33_orion_table.html)
4) Several star atlases include good lists of both double stars and brighter deep sky objects. I have used Astrocards for observing projects, and they work great for Messiers, brighter NGC objects, and many Herschel 400 targets (see http://www.astronomy-mall.com/regular/products/astro-cards/). I don't find the Astro card set for double stars to be as useful as the rest, however. (Unlike the other card sets, there are no blow ups of target regions, and it can be hard to located the interesting doubles in a constellation-wide view.)
5) Jamie Dillon, has been working on his "Dickinsons", the list of objects included with good text descriptions in the Edmund Mag 6 Star atlas. Many of these are double stars and brighter deep sky objects that could be chased down from a near-town site.
6) The Orion Deep Map 600 has Steve Gottlieb's great list of the best deep sky objects,and descriptions of about 85 double and multiple stars (see Ray Cash's page for more information and on-line version of lists: http://sbcglobal.net/raycash/dm600.htm)
I like the whole sky map format, and the object selection and descriptions, even though there aren't enough stars on the map to star hop effectively to the dimmer objects. This is an excellent resource if your view is obstructed in particular directions because of trees, lights, fences, etc. The large scale map format of Deep Map 600 makes it easy to find a particular slice of the sky, and points out lots of rewarding objects for whatever slice you've got.
7) My own recent favorite Atlas of relatively bright targets and double stars is the Observer's Sky Atlas by E. Karkoschka. This is a great compact atlas for near home viewing. It's small enough to fit in a coat pocket. It has both overview charts (mag. 6) and then higher density charts around regions of interest (mag. 9) on the same page. This combines both an overall view, and a useful blow up with lots of stars to help find the objects (sort of like having a combination of Bright Star Atlas and Sky Atlas 2000 resolution together for selected target regions).
The book includes a large amount of useful descriptive information about the objects on the page facing each chart. This includes both verbal descriptions of deep sky objects, and lots of interesting data on stars, star colors, variables, and interesting doubles to be seen on each chart. Lots of this information goes substantially beyond what you see in a usual list of objects in a beginner atlas, including distances to stars and objects, B-V color information, ratings for difficulty of viewing, orbit projections over the next 10 or 20 years for rapidly changing double stars, variable star predictions, and lists of furthest-closest, brightest-dimmest, largest-smallest, object sizes and intrinsic brightnesses that provide an interesting perspective on things amateurs look at in telescopes. Much of this information may be overkill for people just starting out, but I have found it to be very useful. The book charts 110 Messiers and 140 additional deep sky targets of similar brightness, plus 250 double and 80 variable stars that provide an instant list of near-town targets, complete with charts, in a book you can fit in a jacket pocket.
8) Alan MacRobert's Star Hopping for Backyard Astronomers is also an outstanding way to organize short observing sessions near home. I originally saw a recommendation for the book in an article by Alister Ling on Ray Cash's web page, and finally got a copy this fall. MacRobert is a very interesting writer and an excellent tour guide who both picks very interesting objects, describes them well, and gives enough theoretical background to teach you something at the same time. He majored in physics and manages to slip in a surprising amount of information in the course of the star hops. Many of his targets are bright enough to chase down from near town with a 6-inch telescope. I've learned something every time I've gone through one of MacRobert's star hops, and seen many beautiful objects I have not found on any other observing lists. MacRobert has written up 28 different star hops, each of which could serve as the basis of a near-town observing session. Fourteen are collected in the book, and 14 additional star hops have subsequently been published as occasional articles in Sky and Telescope. I am impressed enough by the book to be making copies of his other Sky and Tel articles from the library.
9). Planets also look great from anywhere. I'll look at Jupiter and Saturn any night they are up. I also enjoy shadow and moon transits on Jupiter, and keep a list of all the events for the year in an electronic file on the Palm Pilot (see http://www.projectpluto.com/jevent.htm). Month by month lists are also published each month in Sky and Telescope.
10) And of course the moon itself could provide a lifetime of observing projects. Dave North's regular column in SJAA Ephemeris helped stimulate my own interest in the giant ball in the sky (http://ephemeris.sjaa.net/). Get a Rukl atlas and try crater hopping instead of star hopping along the terminator any night the moon is up (even deep sky mavens have been known to try this on occasion, see http://www.observers.org/reports/99.01.27.2.html). Try finding all the objects in the 50 views of the moon series at the back of Rukl. Try looking at a region of the moon and working out the temporal order of events using the law of superposition. (The classic example is Imbrium then Archimedes, then basin filling, then Eratosthenes, then Copernicus.) Search for new sunset and sunrise rays ( http://www.shallowsky.com/moon/ruklindex.html#R , http://www.lunar-occultations.com/rlo/moon/lunarray.htm , http://www.observers.org/reports/2000.09.18.html ). Sketch the play of light and dark as the terminator advances during an observing session. Compare your observations with those of many other observers at Akkana's excellent website ( http://www.shallowsky.com/moon/hitchhiker.html ). Even on a full moon weekend with clouds in the sky, you can set up near home and spend a very enjoyable night pushing your telescope and observing skills. Last Saturday's session with Plato craters was a lot of fun, and didn't require a long drive or favorable weather forecast ( http://www.observers.org/reports/2000.10.14.4.html ).
Tonight the moon does not come up 'til late, the skies look clear, and I am looking forward to going to Henry Coe State Park to chase down more deep sky objects from the Herschel II list. I can't wait. It has been nearly a month since my last opportunity to travel to a reasonably dark sky site with a telescope. Since going last month, however, I have been able to set up a scope 14 times around home. The in-town sessions have provide great views of deep-sky objects, double stars, open clusters, planets, and the moon, and great practice for pulling out detail at the eyepiece. I love the dark sky stuff, but there is a whole solar system, galaxy, and universe of things to see in the sky. Observing near home lets me explore it on a regular basis, and keeps the rust and cobwebs out as well.
Mail to: David