IAU designations
The official SDSS designation for an object is
SDSS JHHMMSS.ss+DDMMSS.s
where the coordinates are truncated, not rounded. This format must be
used at least once for every object listed in a paper using SDSS data.
When abbreviating the object name in the text please use the "J" to
indicate the equinox of the coordinates. For example
SDSS J123456.89-012345.6 could be abbreviated as
SDSSJ1234
SDSSJ1234-0123
Please refer to the CDS
dictionary on SDSS for further information.
Why bother?
The following is an excerpt from a message by Helene Dickel, the
Chair of the IAU Working Group Designations.
To illustrate the kind of confusion that shortened names can lead
to, consider the source in the Fan et al. paper in ApJ 526, L57, 1999
properly designated SDSSp J153259.96-003944.1 which is then referred
to as SDSS 1533-00 for brevity. Not only is there no J but the RA has
been rounded instead of truncated. Without the explicit J, one may
assume these are B1950 coordinates. If a subsequent author only gives
the shortened name, then a reader searching in NED with IAU format on
1533-00, assuming B1950 coordinates, specifying acronym SDSS but
nothing for the object type, would be given 243 objects that might be
the one in question. Most begin with J2000 RA of 1533, 1534, or
1535. You can narrow the choices if you realize that SDSS source names
are based on J2000 coordinates and that this source is a QSO. Then
there are 9 choices which include SDSS J153306.42+000635.1 and SDSSp
J153259.96-003944.1 Searching for SDSS 1532-0039 assuming J2000
coordinates and QSO yields two choices SDSS J153243.67-004342.5 and
SDSSp J153259.96-003944.1 However, if you think SDSS 1532-0039 uses
B1950 coordinates and don't specify a QSO, you are given 11
possibilities which start with RA 1534 or 1535 and Dec mostly start
with 004, NONE of which include the relevant source SDSSp
J153259.96-003944.1!
It is not just the earlier papers that give shortened names without
the J. A recent paper in AJ gives SDSSHHMM+DDMM with no full
coordinates and a website as the reference. It took over 2 hours with
the help of NED to track down the original SDSSp designations and
references for those three SDSS sources plus several other sources
whose designations were equally corrupted. Following discussions with
the Editor and Author, an Addendum is being published which includes a
table giving the short name, the official SDSS or SDSSp full
designation (and the full designation of the other sources), precise
J2000 coordinates, and the published reference for each source.
Editors and journal readers would appreciate having this information
already available when you publish your papers.
Last modified: Mon Apr 21 13:39:08 CDT 2003
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