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Constellation Information

Explanation

Constellations are groupings of stars in the sky. Observers use these groupings to navigate the otherwise random placement of the stars.

The following pieces of information about a constellation are officially standardized by the IAU, the International Astronomical Union:

1. Latin name
2. Latin genitive (possesive) form of the name
3. 3-character abbreviation ("3CA" in the table below)
4. Constellation boundaries (not included in the table below)

The Latin genitive form is used to denote star names in some catalogs. For example, the "alpha" star of Ursa Minor, is called "alpha Ursae Minoris" (i.e., "alpha of Ursa Minor"), and is usually shortened in print to "alpha UMi". The proper name of this star is Polaris.

The constellation boundaries were set in 1930 so that all the boundaries lay along constant lines of right ascension or declination at epoch 1875, in order to correspond with a popular catalog. Of course, the Earth's rotational precession since then has caused these lines to shift so that they no longer lie along constant lines of right ascension or declination.

The English names, which are usually just translations from the Latin, are not standardized. For example, Ursa Major is called the "Great Bear", "Greater Bear", "Large Bear", or "Big Bear".

The way that the constellation figures are constructed — which stars in the constellation are connected to make the constellation figure — is also not standardized. There are many variations in various sources.

The last three columns of the table include information about the brightest star in the constellation. Its position in the sky — right ascension (RA) and declination (Decl) — give an indication of the position of the constellation itself. One constellation, Serpens, the Serpent, is split into two parts which lie on either side of Ophiuchus, the Serpent Holder, and each part has its own row in the table.

Here are two other forms of the table below:

1. Pre-formatted Text File
2. Comma-separated Value File

The first can be used with any text editor or word processor, the second with a database or spreadsheet program.

You may need to horizontally scroll the table.

There are many other sources of information about the constellations on the web. Here are a few links:

1. Stars and Constellations
2. SkyEye - 88 Constellations

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Copyright 2020 Dale A. Dellutri
Last modified: Saturday, 09-May-2020 16:06:38 EDT