Letter to the Editor: NSV 11749, an Elder Sibling of the Born-again Stars V605 Aql and V4334 Sgr?

MILLER BERTOLAMI, M. M.; ROHRMANN, R. D.; GRANADA, A.; ALTHAUS, L. G.

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2011 vol. 743 p. 1 - 6

0004-637X

We argue that NSV 11749, an eruption observed in the early twentieth century, was a rare event known as "verylate thermal pulse" (VLTP). To support our argument we compare the light curve of NSV 11749 with those of thetwo bona fide VLTP objects known to date, V4334 Sgr and V605 Aql, and with those predicted by state-of-the-artstellar evolution models. Next, we explore the INT Photometric H-Alpha Survey (IPHAS) and Two Micron All SkySurvey (2MASS) catalogs for possible counterparts of the eruption. Our analysis shows that the VLTP scenariooutperforms all other proposed scenarios as an explanation of NSV 11749. We identify an IPHAS/2MASS sourceat the eruption location of NSV 11749. The derived colors suggest that the object is not enshrouded in a thickdust shell as V605 Aql and V4334 Sgr. Also, the absence of an apparent planetary nebula at the eruption locationsuggests differences with known VLTP objects which might be linked to the intensity of the eruption and the massof the object. Further exploration of this source and scenario seems desirable. If NSV 11749 was a born-again star,it would be the third event of its kind to have been observed and will strongly help us to increase our understandingof the later stages of stellar evolution and violent reactive convective burning.