The variability of Young Stellar Objects (YSOs) have been demonstrated over half a century ago from optical observations. More recent time series photometry of YSOs in the thermal infrared have shown their great potential to probe the structure of inner circumstellar disks (r << 1 AU), in particular the presence of warps and clouds in the disks which may owe their existence to the gravitational torques from close-in planets. For instance the YSOVAR program used the Spitzer IRAC instrument to monitor over 1400~YSOs and establish that 70% of them show significant variability in the mid-IR. Today the Herschel/PACS spectral coverage, sensitivity and stability offer a unique opportunity to access the wavelength regime sensitive to the dust thermal emission from the terrestrial habitable zone through the ice-line where gas giants are expected to form.We propose the HYSOVAR program, an expansion of YSOVAR with the Herschel/PACS Photometer, to monitor the flux variations of 100+ Class I YSOs in Orion over weeks-to-years time scales. This small (9.9 hours) exploratory program would greatly increase the statistics and sensitivity of previous studies in the far-IR, and it would help us identify the physical processes responsible for the observed infrared variability by placing strong constraints on existing models of star and planet formation.
Publication
Hops 383: an Outbursting Class 0 Protostar in Orion | Safron Emily J. et al. | The Astrophysical Journal Letters Volume 800 Issue 1 article id. L5 6 pp. (2015). | 800 | 10.1088/2041-8205/800/1/L5 | 2015ApJ...800L...5S | http://adsabs.harvard.edu/abs/2015ApJ...800L...5S
3D dynamics of the Orion cloud complex. Discovery of coherent radial gas motions at the 100-pc scale | Grossschedl Josefa E. et al. | Astronomy and Astrophysics | null | null | 2021A&A...647A..91G |
A Search for Very Low-luminosity Objects in Gould Belt Clouds | Kim Mi-Ryang et al. | The Astrophysical Journal Supplement Series Volume 225 Issue 2 article id. 26 17 pp. (2016). | 225 | 10.3847/0067-0049/225/2/26 | 2016ApJS..225...26K | http://adsabs.harvard.edu/abs/2016ApJS..225...26K
A Multi-band Catalog of 10978 Star Clusters Associations and Candidates in the Milky Way | Bica Eduardo et al. | The Astronomical Journal Volume 157 Issue 1 article id. 12 14 pp. (2019). | 157 | 10.3847/1538-3881/aaef8d | 2019AJ....157...12B | http://adsabs.harvard.edu/abs/2019AJ....157...12B
Velocity-resolved CII Emission and CII/FIR Mapping along Orion with Herschel | Goicoechea Javier R. et al. | The Astrophysical Journal Volume 812 Issue 1 article id. 75 21 pp. (2015). | 812 | 10.1088/0004-637X/812/1/75 | 2015ApJ...812...75G | http://adsabs.harvard.edu/abs/2015ApJ...812...75G
Herschel Far-infrared Photometric Monitoring of Protostars in the Orion Nebula Cluster | Billot N. et al. | The Astrophysical Journal Letters Volume 753 Issue 2 article id. L35 8 pp. (2012). | 753 | 10.1088/2041-8205/753/2/L35 | 2012ApJ...753L..35B | http://adsabs.harvard.edu/abs/2012ApJ...753L..35B
Nano-grain depletion in photon-dominated regions | Schirmer T. et al. | Astronomy and Astrophysics | null | null | 2022A&A...666A..49S |
Instrument
PACS_PacsPhoto_largeScan
Temporal Coverage
2011-02-25T23:57:13Z/2012-08-27T16:53:57Z
Version
SPG v14.2.0
Mission Description
Herschel was launched on 14 May 2009! It is the fourth cornerstone mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
European Space Agency, billot et al., 2013, 'HYSOVAR: Circumstellar Disks Variability around Young Stellar Objects in the Orion Nebula Cluster with Herschel/PACS', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-g6np211
