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From: stefano@harpo.phyast.pitt.edu (Stefano Casertano)
Subject: [astro] Re: Anyone know where the yale star catalogue may be FTP'd from ?
Message-ID: <1991Mar16.201036.9807@ox.com>
Followup-To: sci.astro
Keywords: Yale Bright Star Catalogue, completeness
Sender: emv@msen.com (Edward Vielmetti, MSEN)
Reply-To: stefano@harpo.phyast.pitt.edu (Stefano Casertano)
Organization: University of Pittsburgh, Department of Physics and Astronomy
References: <9103131403.AA05216@ucbvax.Berkeley.EDU> <1991Mar14.151628.288@ulrik.uio.no> <93191@lll-winken.LLNL.GOV> <103465@unix.cis.pitt.edu>
Date: Sat, 16 Mar 1991 20:10:36 GMT
Approved: emv@msen.com (Edward Vielmetti, MSEN)
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Archive-name: astro/catalog/yale-bright-star/1991-03-15
Archive-directory: mandarin.mit.edu:/astro/data.etc/yale.bright/ [18.82.0.21]
Original-posting-by: stefano@harpo.phyast.pitt.edu (Stefano Casertano)
Original-subject: Re: Anyone know where the yale star catalogue may be FTP'd from ?
Reposted-by: emv@msen.com (Edward Vielmetti, MSEN)

In article <93191@lll-winken.LLNL.GOV> loren@tristan.llnl.gov (Loren Petrich) writes:
>
>	On the subject of the Yale Bright Star Catalog, does anyone
>know how complete it is advertised as?
>
>	The measure I would be interested in is a magnitude upper
>limit.
>
>	Is it complete to only magnitude 5.0, or 6.0, or 7.0?
>
>	And if there are several editions of it, what is the most
>complete one, and where may it be found?
>

The Yale Bright Star Catalog, Fourth Edition (1982), is probably
statistically complete to a visual apparent magnitude (V) of 6.0.  The
Supplement published in 1983 was supposed to bring the completeness
limit to 6.5; in fact, the Catalog+Supplement is probably about only 80%
complete between V=6.4 and 6.5, based on the number of stars.  The
Catalog+Supplement is probably statistically complete for V < 6.3. 

For your reference, the Supplement added only 5 stars with V < 6.0 to the
5085 listed in the Catalog, so it makes little difference whether 
or not the Supplement is used as long as you keep to V < 6.0.

Note that completeness and magnitude limits depend rather sensitively on
color.  Part of the reason for the missed stars is that the original
selection was based on photographic magnitudes, which correspond to
somewhat bluer light and discriminate against very red stars. 

Reference: Bahcall, Casertano and Ratnatunga, Astrophysical Journal
Vol. 320, pp. 515-526, September 1987.

                                           Stefano Casertano
                                           stefano@bondi.phyast.pitt.edu