Astronomical Catalogs Query Pages
Hints and Tips for Easier Use
Difficulties in Finding your Data
Here are some hints and tips to help you deal with the most common
user difficulties with the star catalog interface.
- Can't Match String
- Some of these catalogs are quite old, and the data were
originally formatted using FORTRAN programs writing to punch
cards. There may be some odd conventions in the formatting of
names; you may find that an object called NGC123 is called
NGC-123 in one catalog, NGC<1 space>123 in another, and
NGC<3 spaces>123 in yet another. It depends on how the original
catalog author interpreted the name string.
The wildcard (%) symbol can be very helpful here. If your search
for NGC123 fails, you might want to try NGC%123
-- this may match more data than you wanted, since it will
return NGC 1123 as well, but it will ignore any number
of intervening spaces. Using the "write your own" entry box
at the foot of the page, you can be even more clever and search
for Name like 'NGC %123'
- Exceeded Limit?
- With a complex query it is sometimes easy to get distracted
(particularly since you can't see all of your search parameters
at once); when you get 0 records returned, be sure to check
the SQL statement and verify that all the values you specified
are within the expected ranges of values for their respective
columns. A typo in the RA field can lead to great frustration.
If you have difficulties using this interface, send mail to
webmaster (below). This Hints page will grow as you report
your problems.
webmaster@ucolick.org
De Clarke
UCO/Lick Observatory
University of California
Santa Cruz, CA 95064
Tel: +1 408 459 2630
Fax: +1 408 454 9863