There is growing evidence that the star formation process is in facthighly dynamic, on timescales from days to centuries. The temporalvariability is a new and powerful diagnostic tool to study Young StellarObjects (YSOs). Depending on the time scale of the variability in themid and far infrared we can learn about different physical mechanismsshaping their structure and dynamics. Here we propose to extend ournear and mid infrared study of variable YSOs in the young open clusterIC 348 to the far infrared (70 and 160 micron) using Herschel/PACS.We will constrain the frequency of far infrared variability and comparethe observed time dependent behavior with protostellar and disk modelsto understand its origin.Possible mechanisms include fluctuations in the accretion luminosity, orechoes of inner disk structural changes projected onto the infallingenvelope or flared outer disk surface. Our sample in IC348 covers a largepart of the evolutionary sequence of YSOs from class I sources to transitional disks. The cadence of the requested observations allow us tostudy variations on time scales from days to months that could be extended to several years using our Spitzer/MIPS data. This OT2 proposal is an essential complement of our GT2 program covering one visibility epoch,
Publication
The (w)hole survey: An unbiased sample study of transition disk candidates based on Spitzer catalogs | van der Marel N. et al. | Astronomy & Astrophysics Volume 592 id.A126 36 pp. | 592 | 10.1051\\/0004-6361\\/201628075 | 2016A&A...592A.126V | http://adsabs.harvard.edu/abs/2016A%26A...592A.126V
The Extraordinary Far-infrared Variation of a Protostar: Herschel/PACS Observations of LRLL54361 | Balog Zoltan et al. | The Astrophysical Journal Letters Volume 789 Issue 2 article id. L38 5 pp. (2014). | 789 | 10.1088\\/2041-8205\\/789\\/2\\/L38 | 2014ApJ...789L..38B | http://adsabs.harvard.edu/abs/2014ApJ...789L..38B
Catalog of High Protostellar Surface Density Regions in Nearby Embedded Clusters | Li Juan et al. | The Astrophysical Journal Volume 871 Issue 2 article id. 163 18 pp. (2019). | 871 | 10.3847\\/1538-4357\\/aaf652 | 2019ApJ...871..163L | http://adsabs.harvard.edu/abs/2019ApJ...871..163L
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
Instrument
PACS_PacsPhoto_largeScan
Temporal Coverage
2012-08-19T01:01:26Z/2012-08-28T03:47:22Z
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, balog et al., 2013, 'Multi-epoch observations of IC 348: Using Far Infrared Variability to Constrain\ntheDust Structure in Young Stellar Objects', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-hmidync
