A Mystery in Chamaeleon: Serendipitous Discovery of a Galactic Symbiotic Nova

Abstract

We present the serendipitous discovery of a low luminosity nova occurring in a symbiotic binary star system in the Milky Way. We lay out the extensive archival data alongside new follow-up observations related to the stellar object V${}^{\ast }$ CN Cha in the constellation of Chamaeleon. The object had long period ($\sim 250$day), high amplitude ($\sim 3$mag) optical variability in its recent past, preceding an increase in optical brightness by $\sim 8$magnitudes and a persistence at this luminosity for about 3 years, followed by a period of $\sim 1.4\mathrm{mag}{\mathrm{yr}}^{-1}$ dimming. The object's current optical luminosity seems to be dominated by H$\alpha$ emission, which also exhibits blue-shifted absorption (a P-Cygni-like profile). After consideration of a number of theories to explain these myriad observations, we determine that V${}^{\ast }$ CN Cha is most likely a symbiotic (an evolved star-white dwarf binary) system which has undergone a long-duration, low luminosity, nova. Interpreted in this way, the outburst in V${}^{\ast }$ CN Cha is among the lowest luminosity novae ever observed.

arXiv commentSubmitted to AJ, 19 pages, 9 figure

References in corpus (47)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Gaia mission
• The Transiting Exoplanet Survey Satellite
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Theory of Star Formation
• The SIMBAD astronomical database
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• The VizieR database of Astronomical Catalogues
• galpy: A Python Library for Galactic Dynamics
• Understanding the Lomb-Scargle Periodogram
• Dark Energy Survey Year 1 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• The Infrared Astronomical Mission AKARI
• Initial Performance of the NEOWISE Reactivation Mission
• Optimal Techniques in Two-dimensional Spectroscopy: Background Subtraction for the 21st Century
• The SDSS View of the Palomar-Green Bright Quasar Survey
• SkyMapper Southern Survey: First Data Release (DR1)
• The RAdial Velocity Experiment (RAVE): Fourth data release
• A Wide Symbiotic Channel to Type Ia Supernovae
• 4MOST: Project overview and information for the First Call for Proposals
• The Biggest Splash
• A Large Catalog of Accurate Distances to Local Molecular Clouds: The Gaia DR2 Edition
• The Evolution of Early-Type Galaxies in Distant Clusters II: Internal Kinematics of 55 Galaxies in the z=0.33 Cluster CL1358+62
• Optical Imaging of Nova Shells and the Maximum Magnitude-Rate of Decline Relationship
• The Thermonuclear Runaway and the Classical Nova Outburst
• Evidence for an FU Orionis-like Outburst from a Classical T Tauri Star
• SPIRITS: Uncovering Unusual Infrared Transients With Spitzer
• A census of symbiotic stars in the 2MASS, WISE and Gaia surveys
• Connecting RS OPh to [some] Type Ia Supernovae
• On the Progenitors of Galactic Novae
• The ASAS-SN Catalog of Variable Stars V: Variables in the Southern Hemisphere
• The vertical motion history of disk stars throughout the Galaxy
• Evolution of planetary nebulae II. Population effects on the bright cut-off of the PNLF
• Gaia 17bpi: An FU Ori Type Outburst
• The Swift-UVOT ultraviolet and visible grism calibration
• Evolution of Planetary Nebulae I. An improved synthetic model
• Gaia 19ajj: A Young Star Brightening Due to Enhanced Accretion + Reduced Extinction
• On a century of extragalactic novae and the rise of the rapid recurrent novae
• Wind Roche Lobe Overflow as a way to make type Ia supernova from the widest symbiotic systems
• Discovery of a disrupting open cluster far into the Milky Way halo: a recent star formation event in the leading arm of the Magellanic stream?
• Determination of pulsation periods and other parameters of 2875 stars classified as MIRA in the All Sky Automated Survey (ASAS)
• Multi-wavelength Observations of the 2015 Nova in the Local Group Irregular Dwarf Galaxy IC 1613
• Symbiotic stars as possible progenitors of SNe Ia: binary parameters and overall outlook
• The Planetary Nebulae Luminosity Function (PNLF): current perspectives

Cited by in corpus (3)

• Symbiotic stars in the era of modern ground- and space-based surveys
• The GALAH survey: Characterization of emission-line stars with spectral modelling using autoencoders
• Theoretical light curve models of the symbiotic nova CN Cha -- Optical flat peak for three years