Serendipitous discovery of RR Lyrae stars in the Leo V ultra-faint galaxy

Abstract

During the analysis of RR Lyrae stars discovered in the High cadence Transient Survey (HiTS) taken with the Dark Energy Camera at the 4-m telescope at Cerro Tololo Inter-American Observatory, we found a group of three very distant, fundamental mode pulsator RR Lyrae (type ab). The location of these stars agrees with them belonging to the Leo V ultra-faint satellite galaxy, for which no variable stars have been reported to date. The heliocentric distance derived for Leo V based on these stars is 173 +/- 5 kpc. The pulsational properties (amplitudes and periods) of these stars locate them within the locus of the Oosterhoff II group, similar to most other ultra-faint galaxies with known RR Lyrae stars. This serendipitous discovery shows that distant RR Lyrae stars may be used to search for unknown faint stellar systems in the outskirts of the Milky Way.

Accepted in ApJ Letters

References in corpus (17)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• The Catalina Surveys Periodic Variable Star Catalog
• Scaled solar tracks and isochrones in a large region of the Z-Y plane I. From the ZAMS to the TP-AGB end for 0.15 - 2.5 Mo stars
• Introduction to astroML: Machine Learning for Astrophysics
• Leo V: A Companion of a Companion of the Milky Way Galaxy
• Hydra II: a faint and compact Milky Way dwarf galaxy found in the Survey of the Magellanic Stellar History
• Discovery of $\sim$ 9,000 new RR Lyrae in the Southern Catalina Surveys
• An Ultra-Faint Galaxy Candidate Discovered in Early Data from the Magellanic Satellites Survey
• Weak Galactic halo--dwarf spheroidal connection from RR Lyrae stars
• The Leo IV dwarf spheroidal galaxy: color-magnitude diagram and pulsating stars
• The High Cadence Transient Survey (HiTS) - I. Survey design and supernova shock breakout constraints
• Stacking the Invisibles: A Guided Search for Low-Luminosity Milky Way Satellites
• The Period-Luminosity Relation of RR Lyrae Stars in the SDSS Photometric System
• Dynamical evidence for a strong tidal interaction between the Milky Way and its satellite, Leo V
• Predicted properties of RR Lyrae stars in the SDSS photometric system

Cited by in corpus (7)

• Pegasus IV: Discovery and Spectroscopic Confirmation of an Ultra-Faint Dwarf Galaxy in the Constellation Pegasus
• VLT Spectroscopy of Ultra-Faint Dwarf Galaxies. 1. Boötes I, Leo IV, Leo V
• Introducing the Search for Intermediate-mass Black-hole In Nearby Galaxy (SIBLING) Survey
• Identification of RR Lyrae stars in multiband, sparsely-sampled data from the Dark Energy Survey using template fitting and Random Forest classification
• Asteroids' Size Distribution and Colors from HiTS
• RR Lyrae Stars in the Field of Sagittarius II
• rrlfe: Software for Generating and Applying Metallicity Calibrations for RR Lyrae Variable Stars Across a Wide Range of Phases and Temperatures