The UBV Color Evolution of Classical Novae. III. Timestretched ColorMagnitude Diagram of Novae in Outburst
Abstract
We propose a modified colormagnitude diagram for novae in outburst, i.e., (B  V)_{0} versus (M _{ V }  2.5 log f _{s}), where f _{s} is the timescaling factor of a (target) nova against a comparison (template) nova, (B  V)_{0} is the intrinsic B  V color, and M _{ V } is the absolute V magnitude. We dub it the timestretched colormagnitude diagram. We carefully reanalyzed 20 novae based on the timestretching method and revised their extinctions E(B  V), distance moduli in the Vband (m  M)_{ V }, distances d, and timescaling factors f _{s} against the template nova LV Vul. We have found that these 20 nova outburst tracks broadly follow one of the two template tracks, the LV Vul/V1668 Cyg or V1500 Cyg/V1974 Cyg group, in the timestretched colormagnitude diagram. In addition, we estimate the white dwarf masses and (m  M)_{ V } of the novae by directly fitting the absolute V model light curves (M _{ V }) with observational apparent V magnitudes (m _{ V }). A good agreement of the two estimates of (m  M)_{ V } confirms the consistency of the timestretched colormagnitude diagram. Our distance estimates are in good agreement with the results of Gaia Data Release 2.
 Publication:

The Astrophysical Journal Supplement Series
 Pub Date:
 March 2019
 DOI:
 10.3847/15384365/ab0202
 arXiv:
 arXiv:1902.10919
 Bibcode:
 2019ApJS..241....4H
 Keywords:

 novae;
 cataclysmic variables;
 stars: individual: V574 Pup;
 V679 Car;
 V1369 Cen;
 V5666 Sgr;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 89 pages including 52 figures, in ApJS, 241, 4 (2019)