6 papers
RR Lyrae search and stellar populations study in Canis Major: Preliminary Results
Cecilia E. Mateu, A. Katherina Vivas, Robert Zinn +1
We present preliminary results of a RR Lyrae star search and stellar populations study performed in the Canis Major overdensity, spanning an area of 8.35sq deg. The observations we…
VLT Spectroscopy of RR Lyrae Stars in the Sagittarius Tidal Stream
A. Katherina Vivas, Robert Zinn, Carme Gallart
Sixteen RR Lyrae variables from the QUEST survey that lie in the leading arm of the tidal stream from the Sagittarius dSph galaxy have been observed spectroscopically to measure th…
The Selection of RR Lyrae Stars Using Single-epoch Data
Zeljko Ivezic, A. Katherina Vivas, Robert H. Lupton +1
We utilize a complete sample of RR Lyrae stars discovered by the QUEST survey using light curves to design selection criteria based on SDSS colors. Thanks to the sensitivity of the…
Velocities of RR Lyrae Stars in the Sagittarius Tidal Stream
A. Katherina Vivas, Robert Zinn, Carme Gallart
We have measured radial velocities and metallicities of 16 RR Lyrae stars, from the QUEST survey, in the Sagittarius tidal stream at 50 kpc from the galactic center. The distributi…
The low-mass young stellar population in Orion OB1
Cesar Briceño, Nuria Calvet, Anna K. Vivas +2
We present recent results from our ongoing large scale variability survey of the Orion OB1 Association. In an area of ~ 25 square degrees we have unveiled new populations of low-ma…
The CIDA-QUEST Large Scale Variability Survey in the Orion OB Association: initial results
Cesar Briceno, A. Katherina Vivas, Nuria Calvet +2
Using the 8k x 8k CCD Mosaic Camera on the 1m Schmidt telescope in Venezuela, we are conducting a large-scale, deep optical, multiepoch, photometric (BVRIHa) survey over 120 sq.deg…