2014MNRAS.439.1829C -
Mon. Not. R. Astron. Soc., 439, 1829-1854 (2014/April-1)
Extreme infrared variables from UKIDSS - I. A concentration in star-forming regions.
CONTRERAS PENA C., LUCAS P.W., FROEBRICH D., KUMAR M.S.N., GOLDSTEIN J., DREW J.E., ADAMSON A., DAVIS C.J., BARENTSEN G. and WRIGHT N.J.
Abstract (from CDS):
We present initial results of the first panoramic search for high-amplitude near-infrared variability in the Galactic plane. We analyse the widely separated two-epoch K-band photometry in the fifth and seventh data releases of the UKIDSS Galactic plane survey. We find 45 stars with ΔK > 1 mag, including two previously known OH/IR stars and a Nova. Even though the mid-plane is not yet included in the data set, we find the majority (66 per cent) of our sample to be within known star-forming regions (SFRs), with two large concentrations in the Serpens OB2 association (11 stars) and the Cygnus-X complex (12 stars). Sources in SFRs show spectral energy distributions that support classification as young stellar objects (YSOs). This indicates that YSOs dominate the Galactic population of high-amplitude infrared variable stars at low luminosities and therefore likely dominate the total high-amplitude population. Spectroscopic follow up of the DR5 sample shows at least four stars with clear characteristics of eruptive pre-main-sequence variables, two of which are deeply embedded. Our results support the recent concept of eruptive variability comprising a continuum of outburst events with different time-scales and luminosities, but triggered by a similar physical mechanism involving unsteady accretion. Also, we find what appears to be one of the most variable classical Be stars.
Abstract Copyright:
© 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society (2014)
Journal keyword(s):
stars: AGB and post-AGB - stars: low-mass - stars: pre-main-sequence - stars: protostars - stars: variables: T Tauri, Herbig Ae/Be - infrared: stars
Nomenclature:
Table 1: [CLF2014] GPSVNN (Nos GPSV1-GPSV45).
Simbad objects:
66
View the references in ADS