ROTSE All-Sky Surveys for Variable Stars. I. Test Fields

Abstract

The ROTSE-I experiment has generated CCD photometry for the entire Northern sky in two epochs nightly since March 1998. These sky patrol data are a powerful resource for studies of astrophysical transients. As a demonstration project, we present first results of a search for periodic variable stars derived from ROTSE-I observations. Variable identification, period determination, and type classification are conducted via automatic algorithms. In a set of nine ROTSE-I sky patrol fields covering ∼2000 square degrees we identify 1781 periodic variable stars with mean magnitudes between m v =10.0 and m v =15.5. About 90% of these objects are newly identified as variable. Examples of many familiar types are presented. All classifications for this study have been manually confirmed. The selection criteria for this analysis have been conservatively defined, and are known to be biased against some variable classes. This preliminary study includes only 5.6% of the total ROTSE-I sky coverage, suggesting that the full ROTSE-I variable catalog will include more than 32,000 periodic variable stars.

HIDES spectroscopy of bright detached eclipsing binaries from the Kepler field – II. Double- and triple-lined objects

“…Discovered and first identified as a DEB by the Robotic Optical Transient Search Experiment 1 (ROTSE1; Akerlof et al 2000), first reported by Diethel (2001). Later also observed by the Trans-atlantic Exoplanet Survey (TrES; Alonso et al 2004), and listed in the catalogue of variable stars in the Kepler field of view of the All Sky Automated Survey (ASAS-K; Pigulski et al 2009).…”

A search for period changes inδScuti stars with the super-LOTIS sky patrol system

“…The ROTSE team discovered many new variable stars, as describe by Akerlof et al (2000), and has made the data publicly available 1 . Stars from the ROTSE database were chosen, as opposed to stars from the standard catalogs of δ Scuti stars, because the ROTSE stars were readily observable at the time of year when the instrument for this study was available, and were generally fainter than other samples of δ Scuti stars, thus better suited to observation by our instrument.…”

System Description and First Light Curves of the Hungarian Automated Telescope, an Autonomous Observatory for Variability Search

“…Robotic telescopes 4 (capable of computer-controlled multiple observations) have been used for a broad range of projects, such as astrometry (Carlsberg Meridian Telescope;Helmer & Morrison 1985); photoelectric photometry of preselected targets (Fairborn Observatory; Boyd et al 1984); supernova searches (KAIT; Richmond, Treffers, & Filippenko 1993); gamma-ray burst (GRB) follow-up (ROTSE; Akerlof et al 2000;Smith et al 2002, and LOTIS;Park et al 1997Park et al , 2001); exoplanet searches (STARE; Brown & Charbonneau 1999, and Vulcan;Borucki et al 2001); and asteroid searches (TAOS; Chen 1999). The search space is usually narrow, involving specific timescales, light-curve shapes, and intensity ranges.…”

“…4 See, e.g., http://alpha.uni-sw.gwdg.de/∼hessman/MONET. capable of presenting their byproducts to the astronomical community, e.g., OGLE (e.g., Woźniak et al 2002), MACHO (Allsman & Axelrod 2001), and ROTSE (Akerlof et al 2000).…”

“…The upgraded ASAS-3 will produce an order-of-magnitude increase in the data flow over ASAS. 5 Another example showing the incompleteness of our knowledge on bright variable stars is the work by Akerlof et al (2000), who discovered 1781 new variables in a 2000 deg 2 area.…”