University of Hertfordshire

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From the same journal

By the same authors

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  • 906811

    Accepted author manuscript, 1.68 MB, PDF document

  • C. Contreras Peña
  • P.W. Lucas
  • D. Froebrich
  • M.S.N. Kumar
  • J. Goldstein
  • J.E. Drew
  • A.J. Adamson
  • C.J. Davis
  • Geert Barentsen
  • N.J. Wright
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Original languageEnglish
Pages (from-to)1829-1854
Number of pages26
JournalMonthly Notices of the Royal Astronomical Society
Volume439
Issue2
DOIs
Publication statusPublished - 1 Apr 2014

Abstract

We present initial results of the first panoramic search for high-amplitude near-infrared variability in theGalactic 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 midplane 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 premain- 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 timescales 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.

ID: 7099259