SPORIABYSO ivo://nasa.heasarc/sporiabyso NASA/GSFC HEASARC Megeath et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains results from a survey of the Orion A and B molecular clouds undertaken with the IRAC and MIPS instruments on board Spitzer. In total, five distinct fields were mapped, covering 9 deg<sup>2</sup> in five mid-IR bands spanning 3 - 24 microns (µm). The survey includes the Orion Nebula Cluster, the Lynds 1641, 1630, and 1622 dark clouds, and the NGC 2023, 2024, 2068, and 2071 nebulae. These data are merged with the Two Micron All Sky Survey point source catalog to generate a catalog of eight-band photometry. The authors identify 3479 dusty young stellar objects (YSOs) in the Orion molecular clouds by searching for point sources with mid-IR colors indicative of reprocessed light from dusty disks or in-falling envelopes. The YSOs are subsequently classified on the basis of their mid-IR colors and their spatial distributions are presented. The authors classify 2991 of the YSOs as pre-main-sequence stars with disks and 488 as likely protostars. Most of the sources were observed with IRAC in two to three epochs over six months; the authors search for variability between the epochs by looking for correlated variability in the 3.6 and 4.5 um bands. They find that 50% of the dusty YSOs show variability. The variations are typically small (~ 0.2 mag) with the protostars showing a higher incidence of variability and larger variations. The observed correlations between the 3.6, 4.5, 5.8, and 8 um variability suggests that we are observing variations in the heating of the inner disk due to changes in the accretion luminosity or rotating accretion hot spots. This table was created by the HEASARC in January 2013 based on an electronic version of Table 4 from the reference paper which was obtained from the AJ web site. This is a service provided by NASA HEASARC . 2012AJ....144..192M https://heasarc.gsfc.nasa.gov/W3Browse/all/sporiabyso.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=sporiabyso& GET text/xml 180 99999 true 85.67783333 -10.41925 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=sporiabyso GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_sporiabyso&Action=More+Options&Action=Parameter+Search&ConeAdd=1 STAR CATALOG 0.0166666666666667 Infrared public sporiabyso Spitzer Survey of Orion A and B Molecular Clouds YSOs Catalog source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable name Source Designation meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable hmag 2MASS H Band Magnitude mag phot.mag;em.IR.H double nullable hmag_error Uncertainty in 2MASS H Band Magnitude mag stat.error;phot.mag;em.IR.H double nullable irac_3p6_um_mag Spitzer/IRAC 3.6-Micron Band Magnitude mag phot.mag;em.IR.3-4um double nullable irac_3p6_um_mag_error Uncertainty in Spitzer/IRAC 3.6-Micron Band Magnitude mag stat.error;em.IR.3-4um double nullable broad_type Classification src.class char nullable jmag_error Uncertainty in 2MASS J Band Magnitude mag stat.error;phot.mag;em.IR.J double nullable kmag_extinction Extinction in the K Band phys.absorption;em.IR.K double nullable lii Galactic Longitude degree pos.galactic.lon double nullable irac_5p8_um_mag Spitzer/IRAC 5.8-Micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable irac_8p0_um_mag_error Uncertainty in Spitzer/IRAC 8.0-Micron Band Magnitude mag stat.error;em.IR.4-8um double nullable kmag 2MASS K_S Band Magnitude mag phot.mag;em.IR.K double nullable irac_4p5_um_mag_error Uncertainty in Spitzer/IRAC 4.5-Micron Band Magnitude mag stat.error;em.IR.4-8um double nullable irac_spectral_index IRAC Spectral Index spect.index;em.IR double nullable kmag_error Uncertainty in 2MASS K_S Band Magnitude mag stat.error;phot.mag;em.IR.K double nullable irac_4p5_um_mag Spitzer/IRAC 4.5-Micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable irac_5p8_um_mag_error Uncertainty in Spitzer/IRAC 5.8-Micron Band Magnitude mag stat.error;em.IR.4-8um double nullable irac_8p0_um_mag Spitzer/IRAC 8.0-Micron Band Magnitude mag phot.mag;em.IR.4-8um double nullable mips_24_um_mag_error Uncertainty in Spitzer/MIPS 24-Micron Band Magnitude mag stat.error;em.IR.15-30um double nullable bii Galactic Latitude degree pos.galactic.lat double nullable mips_24_um_mag Spitzer/MIPS 24-Micron Band Magnitude mag phot.mag;em.IR.15-30um double nullable jmag 2MASS J Band Magnitude mag phot.mag;em.IR.J double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable