| Issue |
Astron. Astrophys. Suppl. Ser.
Volume 122, Number 1, April I 1997
|
|
|---|---|---|
| Page(s) | 1 - 7 | |
| DOI | https://doi.org/10.1051/aas:1997292 | |
| Published online | 15 April 1997 | |
CCD photometry of variable stars in the field of the globular cluster NGC 6397*
Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw, Poland
Send offprint request to: J. Kaluzny
Received:
12
February
1996
Accepted:
18
June
1996
The 
field including the central part of
the globular cluster NGC 6397 was surveyed in a search for
short-period variable stars.
We obtained light curves for 6 close binaries, 2 SX Phe stars
and 1 RR Lyrae variable, 7 of which are new discoveries.
Both identified SX Phe variables are likely members of the cluster.
One of the identified eclipsing binaries is most probably a field star
while for
the remaining 5 binaries our data do not preclude cluster membership.
A 
. 
color-magnitude diagram extending from the
tip of the red giant branch to below the main-sequence turnoff
is presented.
Key words: globular clusters: individual: NGC 6397 / star: variables: other / HR diagram / blue stragglers / stars: close binaries
© European Southern Observatory (ESO), 1997