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Double Stars - An Introduction


This project is dedicated exclusively to the observation and photography of double and multiple stars.

Most of us rarely observe doubles. Of course, Albireo and epsilon Lyra are presented often at star parties – but not much else.
Doubles and multiples are part of the glory of the night sky. If we look closely we detect their grandness: Their magnitude, distances, colors and the surrounding star field are always different.
Splitting close binaries or such with large magnitude differences require practice, which is part of the joy. As so often the sky reveals its beauty only at second glance.
Doubles are targets for everyone. They don't require large optics or a very dark sky. They require, however, our empathy for them.

Data sources

The data is mainly based on the Washington Double Star Catalog (WDS) and the Sixth Catalog of Orbits of Visual Binary Stars as of 17 June 2021. In addition, further designations of double stars (e.g. proper names) are given.

Additional websites

Contributing observations and photographs

For individual submissions, an email is fine, which should contain all necessary information (see below). In case of regular or especially many submissions, these should be sent in CSV format (a simple text file).

The CSV file contains one observation per line. The individual fields are separated by a semicolon (;). If a field itself contains a semicolon, the contents of this field are enclosed in quotation marks ("). In total there are 9 fields. Ideally, the character encoding of the CSV file is UTF-8, but other encodings are also accepted.

Description of the individual fields:

Name of the double star A common name (e.g. 13 Her, STF7, Porrima) should be used. Special characters are not permitted, e.g. for Greek letters. Instead of ε epsilon must be written. Spaces in the name are only allowed in certain cases. Bayer or Flamsteed designations are always written with, catalogue designations such as STF2098 without whitespace. There are exceptions such as H5 82, where a whitespace is required.
Components of the double star Double star components as used in the WDS catalog. If the observation relates to a single pair, the information is mandatory if there are more than two components. Typical values are AB, A-BC or Aa-Bb. In some cases you may want to describe a multiple star. Here the information of the components is not necessary and should be included in the description.
Rating If the double star is considered recommendable, a rating can be given here. 1,2 or 3 stars (*,**,***) are allowed. Alternatively, this can also be written as a number (1,2,3). If an observer rates a double star several times, but differently, only the highest rating counts. The field can also remain empty. The total rating of a double/multiple star results from the average of all ratings of the observers.
Aperture If a telescope is used, the information is given as an integer (in mm). Binoculars are noted as follows: 8x40, 15x70, etc. When observing with the naked eye, 0 or A is entered. For visual observations the value is required, for photographic observations it is optional.
Magnification Specifies the reference magnification. This information does not apply to binoculars. If several magnifications are used, these can simply be mentioned in the description. In the case of photographic observation or observation with the naked eye, this information is not required.
Sketches/Photographs List of images separated by a comma (,). The names of the image files must exactly match those in the list. Upper/lower case is taken into account. Spaces in the file name should be avoided. Please only specify the file name without path. The format of the images can be JPG, GIF or PNG.
Description (GER) Description in German language.
Description (ENG) Description in English language.
Notes Personal notes or remarks to me which will not be published. This column is optional.

In addition to the observations, information about the observer is of course necessary:

Additional notes: