First Data Release

Here we present the first data release from YSOVAR, which includes light curves primarily from Orion. YSOVAR was approved for 550 hours of time, with the goal of obtaining the first extensive mid-infrared time-series photometry of the central part of the Orion Nebula Cluster plus eleven other, smaller star-forming cores. YSOVAR data should help reveal the structure of the inner disk region of YSOs, provide new constraints on accretion and extinction variability, identify new PMS eclipsing binaries, and help identify new very low mass substellar members of the surveyed clusters.

Almost half of the allocated YSOVAR Spitzer observing time was devoted to time series photometry of a 0.9 square degree region centered on the Trapezium cluster in Orion, beginning on October 24, 2009 and lasting for 40 days (essentially the entire Spitzer visibility window for Orion).

In addition to the IRAC data, we also obtained optical and near-IR time series photometry for the same region during October through December 2009. These data were obtained with a variety of telescopes (SLOTIS, APO, CFHT, UKIRT, as well as others). For this first release of the processed data from the Orion YSOVAR observations, we only provide data from the four facilities explicitly mentioned above.

Rho Ophiuchus Data Products Provided in this Delivery:

We provide the IRAC 3.6 (channel 1) and 4.5 (channel 2) micron light curves for six objects in Rho Ophiuchus presented by Faesi et al. (2012):

• GY292: IRAC1 data
• GY292: IRAC2 data
• GY308: IRAC1 data
• GY292: IRAC1 data
• GY292: IRAC2 data
• ISY_J162625.24-242323.9: IRAC1 data
• ISY_J162625.24-242323.9: IRAC2 data
• YLW15a: IRAC1 data
• YLW15a: IRAC2 data
• YLW16b: IRAC1 data
• YLW16b: IRAC2 data

The columns in each file are MJD, magnitude, and uncertainty.

Note that there were no IRAC 2 observations of GY308.

Orion Data Products Provided in this Delivery:

(See the Data description document for more info on each data product.)

1. Data description document

2. Access to the YSOVAR database access

3. JPEG color of the FOV we surveyed:

• IRAC
• IRAC+2MASS

4. FITS files for the 3.6 and 4.5 micron mosaics built combining the first two weeks of data:

• [3.6] fits image
• [4.5] fits image

5. Photometry tables for the ONC Stars:

• Table for the 1396 ONC Stars with IR Excesses
• Table for the 1027 ONC candidate members not known to have IR Excesses.

6. Plots of multi-wavelength light curves for the Oct. 24 - Dec. 4 time period for the Orion members in our FOV:

• YSO light curves ps file
• No IR excess light curves ps file

7. Orion time series photometry tables:

• IRAC1 gzipped tar file
• IRAC2 gzipped tar file
• J UKIRT gzipped tar file
• J CFHT gzipped tar file
• K CFHT gzipped tar file
• I APO gzipped tar file
• I SLOTIS gzipped tar file