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Astronomical Resources

Until I get it better organized, this is just a collection of assorted astronomical resources. Think of it as an astronomical attic full of assorted stuff, kinda like the "junk drawer" in your Grandma's kitchen...

Observing Lists and Programs

There are about as many lists of astronomical objects to observe as there are observers to create them. Obviously there are lots of "observable" objects up there! The following are some of the (maybe) more well known lists and programs.

For more information on these and many other lists, be sure to check out the Astronomical League Observing Clubs page.

The Messier Catalog

The Messier Catalog was compiled by French astronomer Charles Messier in the 1780's as an aid in his quest to find comets. Once he observed an object and determined that it wasn't a comet, it was added to his list to avoid mistaking it for one in the future. The list was later supplemented with entries by his contemporary, Pierre Mechain, as well as through the research of Dr. Helen Sawyer Hogg and Dr. Owen Gingerich. In the form we know it today, there are 110 objects, all visible through a 4 inch (or smaller) instrument. The Messier list is an ideal first "long-term" observing project.

The Astronomical League's Messier Club page

The Caldwell List

The Caldwell Catalog was compiled by well-known British amateur astronomer Sir Patrick Moore. It presents a reasonably-sized list of reasonably-challenging objects for observers who have completed the Messier list, but are looking for something a little less daunting than the Herschel 400. It also includes a few more southerly objects than the Messier list.

The Astronomical League's Caldwell Club page

The Herschel 400

German-born Sir William Herschel was appointed "King's Astronomer" by King George III of England in the late 1700's, following his discovery of the planet Uranus. He was a methodical observer who, along with his sister Caroline, cataloged all he observed from his British location. His son John included observations from the southern sky, bringing the Herschel catalog to more than 5,000 objects. In 1888, J.L.E. Dryer revised and enlarged this catalog to form his famous "New General Catalog" of more than 7,000 objects. Many objects are still referred to by their NGC designations.

Taken from the catalog of Sir William Herschel, the Herschel 400 list was originally compiled by the members of the Ancient City Astronomy Club in St. Augustine, Florida, as an appropriate "next" project for amateurs wishing to progress beyond the Messier list.

The Astronomical League's Herschel 400 Club page

The Herschel II List

For those looking to move beyond the Herschel 400, the Herschel II offers a fairly demanding catalog of an additional 400 deep sky objects, as well as slightly more stringent logging requirements. Added in 1997 to the Astronomical League's stable of observing clubs, the program was developed by the Rose City Astronomers of Portland, Oregon. More details of this long-term project are available on the RCA website.

The Herschel II page on the Rose City Astronomers website

Astronomical League Double Star Club

The Astronomical League's Double Star Club observing list consists of 100 of the finest double stars in the sky. The file linked here is a re-worked, printable web page I made that combines the list and the observing log. The "CSA chart" reference on each object is the (Tirion) Cambridge Star Atlas chart number for that object.

The Astronomical League's Double Star Club page

sci.astro.amateur (s.a.a.) 100

To quote Jeff DeTray from his post on s.a.a (sci.astro.amateur):

"On March 15, 2000, a discussion thread began in this newsgroup when someone posed the question: "What are your favorite non-Messier objects for 8-12" telescopes? " Newsgroup participants responded enthusiastically to the question, posting many messages nominating a wide variety of objects. Fortunately, newsgroup participant Karl Hutchings kept a cumulative list of all the nominations and totaled the number of votes for each object. When the discussion thread wound down a few days later, Karl posted a list of 90 objects that SAA participants had named as their favorites.

The thread was revived in mid-September, 2000, when SAA participants nominated an additional 10 objects, bring the total to 100. This is by no means the only available list of non-Messier objects, and no rigorous criteria have been applied in the selection of the objects. However, since each object was nominated by one or more active observers, we hope you'll find the list interesting and useful."

...I couldn't have said it better myself.

The SAA 100 Objects page

The Constellations

This is just a list of the constellations, their IAU abbrevations and a brief description of what they represent.


This is a somewhat-formatted list of assorted astronomical formulae. I'm no mathematician, but as far as I can tell these seem to be OK... at least, I've not heard any complaints!

Lists and Cross-References

The following are various files, lists and transcriptions of catalogs I've found here and there. I have no reason (yet!) to doubt their accuracy, but I'm pretty much just leaving them as I found them aside from minimal formatting for HTML. I've expended little if any effort to make them complete and self- explanatory, but hopefully they'll be at least somewhat useful.

Abell Planetary Nebulae

Bright Star Catalog

Burnham's Celestial Handbook Objects by Constellation

Carbon Stars

Double Stars

Globular position data table

Observational Data for Galactic Globular Clusters

Common Names for Deep Sky Objects

Orion 600 list of double and colored stars

Tools for Astronomers

Might as well try to include something useful to Joe and Jane Observer... These are various tools for astronomers, both observational and armchair.

SEDS visual limiting magnitude findercharts

Ben Sugerman's Visual Limiting Magnitude Calculator

Larry Bogan's Telescope Limiting Magnitude Calculator

Peter Enzerink's Scopulator

The Planets (Java web app)


Aladin Interactive Sky Atlas

NASA / IPAC Extragalactic Database (NED)

SIMBAD Astronomical Database

The NGC / IC Project

The Interactive NGC Catalog Online

SEDS Messier Catalog

The Digitized Sky Survey

Sloan Digital Sky Survey


Planetary Nebulae Observer's Home Page