How do you name the stars?

[science_man]

Hello, im Nishant, I was wondering how you (in general) name stars. For example star HD 69830. What do the numbers and letters stand for?

 

[border_ruffian]

"Stars have many names. Throughout the ages, people have devised numbering or lettering systems to identify stars within a constellation. A given star may have a different designation in every catalogue in which it appears. However, in addition to all of these identifiers, some of the brighter stars have proper names as well; names like Arcturus or Polaris or Rigel or Sirius or Vega. Most of these names have been handed down from antiquity via Arab astronomers but a few have been coined as recently as the twentieth century. <br /><br />"Please note that only the International Astronomical Union (IAU) has the authority to name celestial objects and they do not sell names to the public. <br /><br />"Beware of any company that claims to "name" stars for you. Such names have no official sanction and are not recognised by any scientific body."<br /><br />http://www.obliquity.com/skyeye/misc/name.html

 

[harmonicaman]

Official names for celestial objects are assigned by the International Astronomical Union. Procedures vary depending on the type of object. Often there is a system for assigning temporary designations as soon as possible after an object is discovered and later on a permanent name.<br /><br />Some commercial companies purport to allow you to name a star. Typically they send you a nice certificate and a piece of a star atlas showing "your" star. <br /><br />The following statement on star naming was approved by the IPS Council June 30, 1988 --<br /><br />The International Planetarium Society's Guidelines on Star Naming:<br /><br />SELLING STAR NAMES:<br /><br />The star names recognized and used by scientists are those that have been published by astronomers at credible scientific institutions. The International Astronomical Union, the worldwide federation of astronomical societies, accepts and uses only those names. Such names are never sold.<br /><br />Private groups in business to make money may claim to "name a star for you or a loved one, providing the perfect gift for many occasions." One organization offers to register that name in a Geneva, Switzerland, vault and to place that name in their beautiful copyrighted catalog.<br /><br />However official-sounding this procedure may seem, the name and the catalog are not recognized or used by any scientific institution. Further, the official-looking star charts that commonly accompany a "purchased star name" are the Becvar charts excerpted from the Atlas Coeli 1950.0. (Other star atlases such as the Atlas Borealis may be used also.) <br /><br />While these are legitimate charts, published by Sky Publishing Corporation, they have been modified by the private "star name" business

 

[doubletruncation]

I think border_ruffian and harmonicaman have both provided excellent answers to this question. I would just like to add that there are lots of cases were objects may obtain an unofficial designation (that is, I don't think the IAU ever "officially" sanctions the name) that people use, these designations are often assigned in the scientific papers where they were discovered or catalogued in some fashion. For example, a variable star in some star cluster may be designated as V5 for the fifth variable found in that cluster, and people in subsequent papers will refer to it as that. Similarly "TrES-1" denotes the first star found to harbor an extrasolar planet by the TrES project. Ultimately the best way to designate what star you're talking about is to give its position on the sky and any other useful measurements (magnitudes in different filters etc.), so typically people will always give those values as well (or list a source where those values are given) unless it's a very well-known naming convention like the HD catalogue. <br /><br />You can purchase a name for a star from some company, but no one is going to use that name in referring to the star. <div class="Discussion_UserSignature"> </div>