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.
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.
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, a 0 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.|
In addition to the observations, information about the observer is of course necessary:
- First name and surname (will be published; abbreviation permitted: R. Zebahl or Robert Z. can be written instead of Robert Zebahl)
- Observer's city/country (will be published; at least the country should be specified)
- personal website (will be published; optional)
- Since the distance of some double stars can change significantly over the years, the date of observation is of interest and can be mentioned in the description.
- Visual & photographic observations must always be placed in separate CSV files.
- The CSV files should always contain all observations, even those already sent in (if this is not the case, we would like to know). This has the advantage that already submitted observations or images can be corrected, updated or removed. If images are replaced, please point this out.
- Sketches or photographs need to be submitted only once if they are not intended to replace existing ones.
- Submissions must contain at least one description or image ( sketch/photo). If both are missing, the observation will not be published.
- If the description is in only one language, it will be used in the German & English version.
- One or two line breaks (for paragraphs) can be used in descriptions. For this purpose, '\n' or '\n\n' (without quotation marks) must be inserted in the description.
- Since mistakes or unfavorably chosen designations of double stars cannot be avoided in the submissions, corrections are always necessary. We will do most of this ourselves and return the corrected CSV file. There is a short answer from us in any case. It would be good to wait for an answer before adding new observations.
- CSV files do not necessarily have to be written by hand. Programs like Microsoft Excel or Libre Office can create such files from tables.
- Observation of ε Lyrae (the specific pair AB-CD) with the naked eye:
STFA37;AB-CD;*;0;;;gerade so trennbar;barely split;
- Observation of ε lyrae (with components A to D) with 150mm aperture and 120x magnification:
epsilon Lyr;;***;150;120;;alle 4 Komponenten A,B,C,D einfach trennbar;;
- Observation of Albireo (AB) with 8x40 binoculars:
Albireo;AB;;8x40;;;Sehr schön!;Wonderful sight!;or
STFA43;AB;;8x40;;;Sehr schön!;Wonderful sight!;
- Photography of STF2098 (includes several components):
STF2098;;;;;stf2098.jpg;;Taken in 2017 with 18” Dobsonian. Single images with Canon M3 camera, 30s;
- Description with line breaks:
STTA254;AB;;80;33;;Extrem schöner Farbkontrast!\n\nHinweis: Die Komponente A...;Extremely nice view!\n\nNote: The component A...;