| Names |
Geoffrey C. Clayton, B. Sargent, M. L. Boyer, B. A. Whitney, Jacco Th. van Loon, M. Meixner, P. Tisserand, C. Engelbracht, S. Hony, R. Indebetouw, K. A. Misselt, K. Okumura, P. Panuzzo, J. Roman-Duval, M. Sauvage, J. M. Oliveira, M. Sewiło, E. Church |
| Abstract |
The LMC star, SSTISAGE1C J050756.44-703453.9, was first noticed during a
survey of EROS-2 light curves for stars with large irregular brightness
variations typical of the R Coronae Borealis (RCB) class. However, the
visible spectrum showing emission lines including the Balmer and Paschen
series as well as many Fe II lines is emphatically not that of an RCB
star. This star has all of the characteristics of a typical UX Ori star.
It has a spectral type of approximately A2 and has excited an H II
region in its vicinity. However, if it is an LMC member, then it is very
luminous for a Herbig Ae/Be star. It shows irregular drops in brightness
of up to 2 mag, and displays the reddening and "blueing" typical of this
class of stars. Its spectrum, showing a combination of emission and
absorption lines, is typical of a UX Ori star that is in a decline
caused by obscuration from the circumstellar dust. SSTISAGE1C
J050756.44-703453.9 has a strong IR excess and significant emission is
present out to 500 μm. Monte Carlo radiative transfer modeling of the
spectral energy distribution requires that SSTISAGE1C
J050756.44-703453.9 have both a dusty disk as well as a large extended
diffuse envelope to fit both the mid- and far-IR dust emission. This
star is a new member of the UX Ori subclass of the Herbig Ae/Be stars
and only the second such star to be discovered in the LMC. |