Frequently Asked Questions

How many objects are in CSOG?

As of V2.2 (2016), CSOG contains over fourteen thousand objects. Quite a few such as open clusters with an associated nebula and galaxy pairs or groups are combined into single CSOG objects.


Is there an image for every single object in CSOG?

Yes. All but one have a DSS image centered on the object: A depiction of the constellation Ursa Major taken from AstroPlanner is used for the open cluster Collinder 285. Many guides in the Arp Peculiar Galaxies, Hickson Compact Galaxy Groups and Abell Planetary Nebulae editions also contain an SDSS image, where available.


Will there be updates?

Yes. CSOG is a digital publication, allowing for relatively easy updates.
V1 was published in October 2012. CSOG 2.0 was released in December 2013, an interim update followed in January 2014, alongside the release of the Herschel edition. CSOG 2.1 was released on 18 March 2015, along with the new Arp, Holmberg, Dolidze, Dolidze-Dzimselejsvili and Stock editions. The number of editions doubled with the release of CSOG 2.2 in September 2016.

CSOG 2.3 will bring further improvements and new editions. Expect it no earlier than 2018:


How long did it take to write CSOG?

CSOG V1 took 4½ years to complete: Compiling and sorting object lists, creating observing guides, collecting (and correcting) data and coordinates, adding images, creating AstroPlanner planfiles, compiling tours, creating mirrored editions, exporting content for publication, etc. Compiling guides for the constellations of Dorado and Mensa that include the Large Magellanic Cloud, took a complete year.


Is CSOG for GOTO telescopes only?

To the contrary: All CSOG objects include epoch J2000.0 coordinates. The coordinates can be plotted on the starchart you already own. If your starchart does not include the object, simply plot the position and make your starhop. Once close to the object's position, the DSS image in the guide takes over, leaving no doubt whether or not you found the targeted object.
If you insist on having a CSOG-specific finder chart to aid in locating an object, AstroPlanner is any easy way to create them. Planfiles containing all of the objects in the guides and tours are part of the CSOG concept and AstroPlanner allows for quick and easy creation of customized charts.


Tours and AstroPlanner planfiles, but no SkySafari observing lists..? Celstron's SkyPortal app..?

SkySafari is an application that allows creation of custom observing lists. Unfortunately, objects have to be present in the SkySafari object database. As CSOG contains many thousands of objects that are not included in the SkySafari database, CSOG SkySafari observing lists can not be created at this time. Hopefully a true "user objects" feature will be added to SkySafari in a future update. A simple "R.A. / Dec. / Object name" format will do.

The same goes for Celestron's SkyPortal application for use with Evolution telescopes.


DSS Images but no sketches?

CSOG contains over fourteen thousand objects. Sketches for all of these objects do not exist.
But what about sketches for a limited number of objects, such as the Messier edition? The problem is that sketches do not provide for a "standard candle". By definition they are a subjective representation of any object, dependent on the sketcher's equipment, eyesight, artistic abilities, atmospheric conditions at the time of observation and of course the objects' elevation. For sketches to be truly useful and an objective representation of what any object looks like through the eyepiece, all drawings must be comparable. A star of any magnitude must be drawn equal in size every time so as not to confuse them with brighter or fainter ones. Orientation and image size must be identical and, preferably, the object must be at similar elevation to limit atmospheric effects.
To the best of my knowledge, such sketches do not exist. No matter how beautiful a sketch may look, the usefulness for visual astronomy is very limited, especially when considering the huge number of objects in reach of moderately large amateur telescopes.


Why are CSOG guides such large files?

The images in CSOG are uncompressed. This allows users to zoom in on objects when viewed on a computer or tablet, without the image immediately becoming blurred and grainy. The uncompressed images are a major feature of CSOG.


Why are there no links to objects in the index files?

Let's do the math for the 12" edition. Over fourteen thousand objects to link. Assumption is 3 links created every minute, that's 180 every hour. Doing so for 8 hours a day means 1440 links per day. It would then take about 9½ days to complete links for the 12" edition. But wait, counting the mirrored editions there are four different 12" editions. Make that 38 days. How about linking the individual constellation index files, too? Multiple by 2, for a total of 76 days.
Continue with the 8-10" editions, the 5-6" and all of the catalog editions. Linking all of these index files would take close to a year, doing nothing but creating links for eight hours a day. Impossible? No. Undoable? Absolutely.