skip to main content

Title: YSOVAR: MID-INFRARED VARIABILITY IN NGC 1333

As part of the Young Stellar Object VARiability (YSOVAR) program, we monitored NGC 1333 for ∼35 days at 3.6 and 4.5 μm using the Spitzer Space Telescope. We report here on the mid-infrared variability of the point sources in the ∼10′ × ∼20′ area centered on 03:29:06, +31:19:30 (J2000). Out of 701 light curves in either channel, we find 78 variables over the YSOVAR campaign. About half of the members are variable. The variable fraction for the most embedded spectral energy distributions (SEDs) (Class I, flat) is higher than that for less embedded SEDs (Class II), which is in turn higher than the star-like SEDs (Class III). A few objects have amplitudes (10–90th percentile brightness) in [3.6] or [4.5] > 0.2 mag; a more typical amplitude is 0.1–0.15 mag. The largest color change is >0.2 mag. There are 24 periodic objects, with 40% of them being flat SED class. This may mean that the periodic signal is primarily from the disk, not the photosphere, in those cases. We find 9 variables likely to be “dippers,” where texture in the disk occults the central star, and 11 likely to be “bursters,” where accretion instabilities create brightness bursts. There are 39 objectsmore » that have significant trends in [3.6]–[4.5] color over the campaign, about evenly divided between redder-when-fainter (consistent with extinction variations) and bluer-when-fainter. About a third of the 17 Class 0 and/or jet-driving sources from the literature are variable over the YSOVAR campaign, and a larger fraction (∼half) are variable between the YSOVAR campaign and the cryogenic-era Spitzer observations (6–7 years), perhaps because it takes time for the envelope to respond to changes in the central source. The NGC 1333 brown dwarfs do not stand out from the stellar light curves in any way except there is a much larger fraction of periodic objects (∼60% of variable brown dwarfs are periodic, compared to ∼30% of the variables overall)« less
Authors:
 [1] ; ;  [2] ; ; ; ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ; ;  [9] ;  [10] ;  [11] ;  [12] ;
  1. Infrared Science Archive (IRSA), Infrared Processing and Analysis Center (IPAC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States)
  2. Spitzer Science Center (SSC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States)
  3. Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)
  4. Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)
  5. Centro de Investigaciones de Astronomía, Apdo. Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of)
  6. Max Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany)
  7. Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)
  8. Dept. of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)
  9. Depto. Astrofísica, Centro de Astrobiología (INTA-CSIC), ESAC campus, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain)
  10. NASA Exoplanet Science Institute (NExScI), Infrared Processing and Analysis Center (IPAC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States)
  11. Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States)
  12. Department of Physics and Astronomy, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States)
Publication Date:
OSTI Identifier:
22520071
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 150; Journal Issue: 6; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BRIGHTNESS; COLOR; COMPARATIVE EVALUATIONS; DIAGRAMS; ENERGY SPECTRA; PERIODICITY; PHOTOSPHERE; PROTOSTARS; SPACE; STAR ACCRETION; STAR CLUSTERS; STARS; TELESCOPES; VISIBLE RADIATION