Northern Sky Variability Survey: Public Data Release

Abstract

The Northern Sky Variability Survey (NSVS) is a temporal record of the sky over the optical magnitude range from 8 to 15.5. It was conducted in the course of the first-generation Robotic Optical Transient Search Experiment (ROTSE-I) using a robotic system of four comounted unfiltered telephoto lenses equipped with CCD cameras. The survey was conducted from Los Alamos, New Mexico, and primarily covers the entire northern sky. Some data in southern fields between declinations 0 and À38 are also available, although with fewer epochs and noticeably lesser quality. The NSVS contains light curves for approximately 14 million objects. With a 1 yr baseline and typically 100-500 measurements per object, the NSVS is the most extensive record of stellar variability across the bright sky available today. In a median field, bright unsaturated stars attain a point-to-point photometric scatter of $0.02 mag and position errors within 2 00 . At Galactic latitudes jbj < 20 , the data quality is limited by severe blending due to the $14 00 pixel size. We present basic characteristics of the data set and describe data collection, analysis, and distribution. All NSVS photometric measurements are available for on-line public access from the Sky Database for Objects in Time-Domain ((SkyDOT)) at Los Alamos National Laboratory. Copies of the full survey photometry may also be requested on tape.

TheSpitzerspectroscopic survey of S-type stars

“…To estimate the source variability of the S-type stars, we have cross-identified all stars in the GCSS2 with the two major available variability surveys: the All Sky Automated Survey (ASAS) located at the Las Campanas Observatory (Pojmanski et al 2005) and the Northern Sky Variability Survey 3 (NSVS) operated at Los Alamos National Laboratory (Woźniak et al 2004a). This resulted in 1154 S-type stars with V-band light curves.…”

On the nature of the candidate T-Tauri star V501 Aurigae★

“…Numerical constants were adopted from Woźniak et al (2004). Prior to the analysis the light curves from individual observatories/instruments were corrected for small magnitude offsets, with the light curve from WASP being taken as the reference.…”

The quest for companions to post-common envelope binaries

“…Early coverage of HS0705 and NSVS1425 is available from archival data of the Northern Sky Variability Survey (Woźniak et al 2004) 1 , which provides short glimpses of the sky for an extended period of time in 1999, with exposure times between 20 and 80 s. HS0705 was extensively studied from October 2000 on by Drechsel et al (2001). The source was subsequently monitored by Qian et al (2009Qian et al ( , 2010a, and references therein).…”

“…NSVS 14256825 (in short NSVS1425) was discovered as a 13.2 mag variable star in the Northern Sky Variability Survey (Woźniak et al 2004) and identified as an eclipsing binary with a 2.6 h orbital period and an sdB primary by Wils et al (2007). The source seems to be in many respects a twin of HS0705 and the prototype sdB/M-dwarf binary HW Vir (Lee et al 2009).…”