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Peremennye Zvezdy (Variable Stars) 27, No. 8, 2007 Received 19 November; accepted 20 November.
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We present the discovery, photographic and V-band CCD observation of a new High Amplitude Delta Scuti star USNO-A2.0 0975-09853705. |
Several years ago, we started digitization, with 2540 dpi
resolution, of plates of the Moscow archive with two CREO
EverSmart Supreme II scanners of the Sternberg Astronomical
Institute. Later, we initiated the search for new variable stars
on these scanned images. We analyze the scans with the VAST
software (Sokolovsky and Lebedev, 2005) which is based on the
well-known SExtractor package (Bertin and Arnouts, 1996). Some
results of our pilot projects have already been published (see,
for example, Manannikov et al., 2006, and Kolesnikova et al.,
2007). Here we report the first finding on the scans of
(
) plates of
Crimean astrograph centered on 66 Oph (
= 18
00
3,
= +4
22
, J2000.0).
The star USNO-A2.00975-09853705 ( =
17
51
37
90,
= +8
44
01
5 (J2000.0,
2MASS)) was found to be variable on 114 scans of the 66 Oph field
(JD2442867-46977) with a period, a variability amplitude, and a
shape of the phased light curve typical of the High Amplitude
Delta Scuti stars. Our
magnitudes were calibrated using
photographic blue magnitudes of neighboring USNO-A2.0 stars
(Monet et al., 1998).
To confirm the classification, we undertook additional CCD
observations using a SBIG ST2000XM CCD camera and the 60-cm
reflector of the Crimean Laboratory (Sternberg Astronomical
Institute). 345 -band brightness measurements were obtained on
four nights in 2007: July 8-22, JD2454290-304. The images were
dark subtracted, flat-fielded and analyzed with the aperture
photometry package developed by V.P. Goranskij. The comparison
and check stars are marked in Fig.1. The accuracy of our
photometry is 0
024.
Both from our photographic and CCD data, we find the following
light elements:
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Fig. 2.
The photographic and |
Acknowledgements: This study was supported, in part, by the Russian Foundation for Basic Research through grants Nos. 05-02-16289 and 05-02-16688.
References:
Bertin, E., Arnouts, S., 1996, A&AS, 117, 393
Kolesnikova, D., Sokolovsky, K.V., Samus, N.N., Antipin, S.V., 2007, PZP, 7, No. 3
Manannikov, A.L., Sokolovsky, K.V., Samus, N.N., Antipin, S.V., 2006, PZP, 6, No. 34
Monet, D., Bird, A., Canzian, B., et al., 1998, USNO-A2.0, A Catalog of Astrometric Standards, U.S. Naval Observatory, Washington, DC
Sokolovsky, K., Lebedev, A., 2005, in 12th Young Scientists' Conference on Astronomy and Space Physics, Kyiv, Ukraine, April 19-23, 2005, eds.: Simon, A.; Golovin, A., p.79