- ID:
- ivo://CDS.VizieR/J/AJ/150/118
- Title:
- YSOVAR infrared photometry in IRAS 20050+2720
- Short Name:
- J/AJ/150/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a time-variability study of young stellar objects (YSOs) in the cluster IRAS 20050+2720, performed at 3.6 and 4.5{mu}m with the Spitzer Space Telescope; this study is part of the Young Stellar Object VARiability (YSOVAR) project. We have collected light curves for 181 cluster members over 60 days. We find a high variability fraction among embedded cluster members of ca. 70%, whereas young stars without a detectable disk display variability less often (in ca. 50% of the cases) and with lower amplitudes. We detect periodic variability for 33 sources with periods primarily in the range of 2-6 days. Practically all embedded periodic sources display additional variability on top of their periodicity. Furthermore, we analyze the slopes of the tracks that our sources span in the color-magnitude diagram (CMD). We find that sources with long variability time scales tend to display CMD slopes that are at least partially influenced by accretion processes, while sources with short variability timescales tend to display extinction-dominated slopes. We find a tentative trend of X-ray detected cluster members to vary on longer timescales than the X-ray undetected members.
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- ID:
- ivo://CDS.VizieR/J/AJ/148/122
- Title:
- YSOVAR: infrared photometry in Lynds 1688
- Short Name:
- J/AJ/148/122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The emission from young stellar objects (YSOs) in the mid-infrared (mid-IR) is dominated by the inner rim of their circumstellar disks. We present IR data from the Young Stellar Object VARiability (YSOVAR) survey of ~800 objects in the direction of the Lynds 1688 (L1688) star-forming region over four visibility windows spanning 1.6yr using the Spitzer Space Telescope in its warm mission phase. Among all light curves, 57 sources are cluster members identified based on their spectral energy distribution and X-ray emission. Almost all cluster members show significant variability. The amplitude of the variability is larger in more embedded YSOs. Ten out of 57 cluster members have periodic variations in the light curves with periods typically between three and seven days, but even for those sources, significant variability in addition to the periodic signal can be seen. No period is stable over 1.6yr. Nonperiodic light curves often still show a preferred timescale of variability that is longer for more embedded sources. About half of all sources exhibit redder colors in a fainter state. This is compatible with time-variable absorption toward the YSO. The other half becomes bluer when fainter. These colors can only be explained with significant changes in the structure of the inner disk. No relation between mid-IR variability and stellar effective temperature or X-ray spectrum is found.
- ID:
- ivo://CDS.VizieR/J/AJ/150/175
- Title:
- YSOVAR: infrared photometry in NGC 1333
- Short Name:
- J/AJ/150/175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of the Young Stellar Object VARiability (YSOVAR) program, we monitored NGC 1333 for ~35 days at 3.6 and 4.5{mu}m using the Spitzer Space Telescope. We report here on the mid-infrared variability of the point sources in the ~10'x~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]>0.2mag; a more typical amplitude is 0.1-0.15mag. The largest color change is >0.2mag. 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 objects 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).
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/YSOVAR/YSOVAR_I20050LC
- Title:
- YSOVAR IRAS 20050+2720 Light Curve Table
- Short Name:
- YSOVAR_I20050LC
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (IRAC 3.6 and 4.5 micron) time series photometry of the Orion Nebula Cluster plus smaller fields in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. YSOVAR is a sister project to the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264; Cody et al. 2014). Initial YSOVAR results were described in Morales-Calderon et al. (2011). Rebull et al. (2014) describes the details of target selection, data reduction, and other conventions established for this project.
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/YSOVAR/YSOVAR_I20050Obj
- Title:
- YSOVAR IRAS 20050+2720 Object Table
- Short Name:
- YSOVAR_I20050Obj
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (IRAC 3.6 and 4.5 micron) time series photometry of the Orion Nebula Cluster plus smaller fields in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. YSOVAR is a sister project to the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264; Cody et al. 2014). Initial YSOVAR results were described in Morales-Calderon et al. (2011). Rebull et al. (2014) describes the details of target selection, data reduction, and other conventions established for this project.
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/YSOVAR/YSOVAR_L1688_LC
- Title:
- YSOVAR L1688 Light Curve Table
- Short Name:
- YSOVAR_L1688_LC
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (IRAC 3.6 and 4.5 micron) time series photometry of the Orion Nebula Cluster plus smaller fields in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. YSOVAR is a sister project to the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264; Cody et al. 2014). Initial YSOVAR results were described in Morales-Calderon et al. (2011). Rebull et al. (2014) describes the details of target selection, data reduction, and other conventions established for this project.
24167. YSOVAR L1688 Object Table
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/YSOVAR/YSOVAR_L1688_Obj
- Title:
- YSOVAR L1688 Object Table
- Short Name:
- YSOVAR_L1688_Obj
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (IRAC 3.6 and 4.5 micron) time series photometry of the Orion Nebula Cluster plus smaller fields in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. YSOVAR is a sister project to the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264; Cody et al. 2014). Initial YSOVAR results were described in Morales-Calderon et al. (2011). Rebull et al. (2014) describes the details of target selection, data reduction, and other conventions established for this project.
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/YSOVAR/YSOVAR_NGC1333LC
- Title:
- YSOVAR NGC 1333 Light Curve Table
- Short Name:
- YSOVAR_NGC1333LC
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (IRAC 3.6 and 4.5 micron) time series photometry of the Orion Nebula Cluster plus smaller fields in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. YSOVAR is a sister project to the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264; Cody et al. 2014). Initial YSOVAR results were described in Morales-Calderon et al. (2011). Rebull et al. (2014) describes the details of target selection, data reduction, and other conventions established for this project.
24169. YSOVAR NGC 1333 Object Table
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/YSOVAR/YSOVARNGC1333Obj
- Title:
- YSOVAR NGC 1333 Object Table
- Short Name:
- YSOVARNGC1333Obj
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (IRAC 3.6 and 4.5 micron) time series photometry of the Orion Nebula Cluster plus smaller fields in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. YSOVAR is a sister project to the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264; Cody et al. 2014). Initial YSOVAR results were described in Morales-Calderon et al. (2011). Rebull et al. (2014) describes the details of target selection, data reduction, and other conventions established for this project.
- ID:
- ivo://CDS.VizieR/J/ApJ/753/149
- Title:
- YSOVAR: six eclipsing binaries in Orion
- Short Name:
- J/ApJ/753/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Eclipsing binaries (EBs) provide critical laboratories for empirically testing predictions of theoretical models of stellar structure and evolution. Pre-main-sequence (PMS) EBs are particularly valuable, both due to their rarity and the highly dynamic nature of PMS evolution, such that a dense grid of PMS EBs is required to properly calibrate theoretical PMS models. Analyzing multi-epoch, multi-color light curves for ~2400 candidate Orion Nebula Cluster (ONC) members from our Warm Spitzer Exploration Science Program YSOVAR, we have identified 12 stars whose light curves show eclipse features. Four of these 12 EBs are previously known. Supplementing our light curves with follow-up optical and near-infrared spectroscopy, we establish two of the candidates as likely field EBs lying behind the ONC. We confirm the remaining six candidate systems, however, as newly identified ONC PMS EBs. These systems increase the number of known PMS EBs by over 50% and include the highest mass ({theta}^1^ Ori E, for which we provide a complete set of well-determined parameters including component masses of 2.807 and 2.797M_{sun}_) and longest-period (ISOY J053505.71-052354.1, P~20 days) PMS EBs currently known. In two cases ({theta}^1^ Ori E and ISOY J053526.88-044730.7), enough photometric and spectroscopic data exist to attempt an orbit solution and derive the system parameters. For the remaining systems, we combine our data with literature information to provide a preliminary characterization sufficient to guide follow-up investigations of these rare, benchmark systems.
