J/AN/333/706 Bochum survey of the southern Galactic disk (Haas+, 2012)
The Bochum survey of the southern Galactic disk:
I. Survey design and first results on 50 square degrees monitored in 2011.
Haas M., Hackstein M., Ramolla M., Drass H., Watermann R., Lemke R.,
Chini R.
<Astron. Nachrichten, 333, 706-716 (2012)>
=2012AN....333..706H 2012AN....333..706H
ADC_Keywords: Surveys ; Stars, variable ; Photometry
Keywords: surveys - stars: variables: general
Abstract:
We are monitoring a 6° wide stripe along the southern Galactic disk
simultaneously in the r and i bands, using a robotic 15-cm twin
telescope of the Universitatsternwarte Bochum near Cerro Armazones in
Chile. Utilising the telescope's 2.7° field of view, the survey aims
at observing a mosaic of 268 fields once per month and to monitor
dedicated fields once per night. The survey reaches a sensitivity from
10m down to 18m (AB system), with a completeness limit of r∼15.5m
and i∼14.5m which - due to the instrumental pixel size of 2.4" -
refers to stars separated by >3". This brightness range is ideally
suited to examine the intermediately bright stellar population
supposed to be saturated in deep variability surveys with large
telescopes. To connect to deep surveys or to explore faint long term
variables, coadded images of several nights reach a depth of ∼20m.
The astrometric accuracy is better than 1", as determined from the
overlap of neighbouring fields. We describe the survey design, the
data properties and our procedures to derive the light curves and to
extract variable stars. We present a list of ∼2200 variable stars
identified in 50 square degrees with 50-80 observations between May
and October 2011. For bright stars the variability amplitude A reaches
down to A∼0.05m, while at the faint end variations of A>1m are
detected. About 200 stars were known to be variable, and their
amplitudes and periods - as far as determinable from our six month
monitoring - agree with literature values, demonstrating the
performance of the Bochum Galactic Disk Survey.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 12 List of fields in Galactic Disk Survey (GDS)
table2.dat 101 2288 List of variable stars
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [GDS]
5- 13 A9 --- Field GDS field name (NNNN-NNNN)
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 24 F4.1 s RAs Right ascension (J2000)
26 A1 --- DE- Declination sign (J2000)
27- 28 I2 deg DEd Declination (J2000)
30- 31 I2 arcmin DEm Declination (J2000)
33- 34 I2 arcsec DEs Declination (J2000)
36- 37 I2 --- NObs Number of observations
39- 48 A10 "YYYY-MM-DD" Obs1 First night observation date
50- 59 A10 "YYYY-MM-DD" Obs2 Las2 night observation date
61- 65 I5 --- Nsr Number of stars used for the analysis in r-band
67- 69 I3 --- Nvr [70/238] Number of stars identified to be
variable in r-band
71- 75 I5 --- Nsi Number of stars used for the analysis in i-band
77- 79 I3 --- Nvi [91/248] Number of stars identified to be
variable in i-band
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Field Field name of the data set from which the
light curve is created (NNNN-NNNN)
11- 20 F10.6 deg RAdeg Star right ascension (J2000)
22- 31 F10.6 deg DEdeg Star declination (J2000)
33- 34 I2 --- Nr [14/57]?=0 Number of data points of the light
curve used in the r-band
36- 40 F5.2 mag ?=0 Mean brightness of the light curve in
rmag (AB system)
42- 45 F4.2 mag e_ ?=0 Standard deviation on
47- 50 F4.2 mag Trs [0.02/0.5]?=0 Threshold at the brightness of
the star to accept it as variable by means
of the standard deviation in r-band
52- 55 F4.2 mag rAmp ?=0 Amplitude of the light curve in r-band
57- 60 F4.2 mag TrA [0.07/2.0]?=0 Threshold at the brightness of
the star to accept it as variable by means
of the amplitude in r-band
62- 66 F5.2 --- Jr ?=0 Stetson J-Index in r-band
68- 69 I2 --- Ni [14/42]?=0 Number of data points of the light
curve used in the i-band
71- 75 F5.2 mag ?=0 Mean brightness of the light curve in
imag (AB system)
77- 80 F4.2 mag e_ ?=0 Standard deviation on
82- 85 F4.2 mag Tis [0.02/0.5]?=0 Threshold at the brightness of
the star to accept it as variable by means
of the standard deviation in i-band
87- 90 F4.2 mag iAmp ?=0 Amplitude of the light curve in imag
92- 95 F4.2 mag TiA [0.07/2.0]?=0 Threshold at the brightness of
the star to accept it as variable by means
of the amplitude in i-band
97-101 F5.2 --- Ji ?=0 Stetson J-index in i-band
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Acknowledgements:
Martin Haas, haas(at)astro.rub.de
(End) Patricia Vannier [CDS] 27-Mar-2013