RDSTARC

Name

rdstarc

Purpose

Read refnet based star catalog files.

Description

Read star catalog file - there are a number of options and consequences
of running this. The input file can be either in ASCII tabular format
or in binary format. If the file is ASCII you MUST use /NOCONVERT if
you do not want the input file to be modified. Otherwise, it will be
converted to the most appropriate binary format file using starcprmt
before it is read.
There are two types of ASCII files. The old version dating back from the
USNO catalog days, does not contain any proper motion information. This
form of file will naturally map into the v1.0 format file with no loss
of information. This file has 10 columns of data of which only the first
8 are ever examined. The other two columns were for backward compatibility
for some long-forgotten software. These columns are optional and are
ignored if present. The 7 columns that are read are:
col Contents
0-2 -- Right ascension (H, M, S)
3-5 -- Declination (D, M, S).
6 -- Blue magnitude
7 -- Red magnitude
The second type of ASCII file is from Gaia DR1. It has 11 columns of
information and is a newly designed format. During conversion to binary
form, one of two things can happen. If you provide EPOCH, the proper
motion and parallax is applied to the catalog positions and the resulting
coordinates are saved in the v1.0 binary format. If you do not provide
EPOCH, all of the input information is kept and sent back to the user.
In this latter case, the information comes back in the INFO return
structure and the formal arguments are populated with the catalog
information that maps to these arguments but they really aren't of
much use. The columns in the file are:
col Contents
0 Right ascension (encoded as a single sexigesimal string, H:M:S)
1 Declination (encoded as a single sexigemsimal string, D:M:S)
2 RA proper motion (arcsec/year)
3 Dec proper motion (arcsec/year)
4 Parallax (arcsec)
5 RA uncertainty (arcsec)
6 Dec uncertainty (arcsec)
7 RA proper motion uncertainty (arcsec/year)
8 Dec proper motion uncertainty (arcsec/year)
9 Parallax uncertainty (arcsec)
10 G magnitude
If you use NOCONVERT, you must use the full info structure on return

Calling Sequence

rdstarc,starfile,ra,dec,bmag,rmag,nstars

Inputs

starfile - Name of file to read.

Optional Input Parameters

Keyword Input Parameters

SILENT - Flag, if set suppresses all non-error output.
NOCONVERT - Flag, if set, suppresses converting to binary format.
Only works if the file is not already binary. If it's
binary the program dies most unpleasantly.

Outputs

ra - right ascension in radians (J2000)
dec - declination in radians (J2000)
bmag - Blue magnitude
rmag - Red magnitude (see the USNO A2.0 catalog docs to see what this means)
nstars - Number of stars found (can be zero- in this case other
outputs not defined).

Keyword Output Parameters

Common Blocks

Side Effects

Restrictions

There is no version control or fancy validation provided if you bypass
conversion. You really should use this only for tiny files where you
really need to maintain the ASCII version. This is NOT a normal usage.

Procedure

Modification History

Written by Marc W. Buie, Lowell Observatory, 2002/01/07
02/03/10 - MWB, added nstars return value
2007/11/23- Peter L. Collins, Lowell Observatory,
convert to v1.0 binary fmt and add promote call.
2008/10/21, MWB, added SILENT keyword
2014/03/18, MWB, added NOCONVERT keyword
2016/11/05, MWB, added support for proper motion and parallax