A study on the mid-infrared sources that dramatically brightened

Hiroki Onozato, Yoshifusa Ita, Kenji Ono, Misato Fukagawa, Kenshi Yanagisawa, Hideyuki Izumiura, Yoshikazu Nakada, Noriyuki Matsunaga

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3 Citations (Scopus)


We present results of near-infrared (NIR) photometric and spectroscopic observations of mid-infrared (MIR) sources that brightened dramatically. Using Infrared Astronomical Satellite (IRAS), AKARI, and Wide-field Infrared Survey Explorer (WISE) point source catalogs, we found that four sources (IRAS19574+4941, V2494Cyg, IRAS22343+7501, and V583Cas) significantly brightened at MIR wavelengths over a period of 20-30 yr, depending on an interval between two different observation epoch. Little is known about these sources except V2494Cyg, which is considered as an FU Orionis star. Our observation clearly resolves IRAS22343+7501 into four stars (2MASSJ22352345+7517076, 2MASSJ22352442+7517037, [RD95]C, and 2MASSJ22352497+7517113) and the first JHKs photometric data for all four sources are obtained. Two of these stars (2MASSJ22352442+7517037 and 2MASSJ22352497+7517113) are known as T Tau stars. Our spectroscopic observation reveals that IRAS19574+4941 is an M-type evolved star and V583Cas a carbon star. 2MASSJ22352345+7517076 is probably a young stellar object, judging from our observation showing that it has a featureless NIR spectrum and also showed dramatic brightening in NIR (about 4 mag in the Ks band). Likely reasons for dramatic brightening in MIR are discussed in this paper.

Original languageEnglish
Article number39
JournalPublications of the Astronomical Society of Japan
Issue number3
Publication statusPublished - 2015 Apr 8


  • circumstellar matter-infrared
  • late-type-stars
  • pre-main sequence
  • stars-stars

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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