Periodic Accretion Instabilities in the Protostar L1634 IRS 7

Abstract

The small molecular cloud Lynds 1634 contains at least three outflow sources. We found one of these, IRS 7, to be variable with a period of 37.14 +/- 0.04 days and an amplitude of approximately 2 mag in the Ks band. The light curve consists of a quiescent phase with little or no variation, and a rapid outburst phase. During the outburst phase, the rapid brightness variation generates light echoes that propagate into the surrounding molecular cloud, allowing a measurement of the distance to IRS 7 of 404 pc +/- 35 pc. We observed only a marginally significant change in the H - K color during the outburst phase. The K-band spectrum of IRS 7 shows CO bandhead emission but its equivalent width does not change significantly with the phase of the light curve. The H_2 1-0 S(1) line emission does not follow the variability of the continuum flux. We also used the imaging data for a proper motion study of the outflows originating from the IRS 7 and the FIR source IRAS 05173-0555, and confirm that these are indeed distinct outflows.

The paper is accepted for publication in The Astrophysical Journal

References in corpus (7)

• The UKIRT Wide Field Camera ZYJHK Photometric System: Calibration from 2MASS
• A Parallactic Distance of 389 +24/-21 parsecs to the Orion Nebula Cluster from Very Long Baseline Array Observations
• HOPS 383: An Outbursting Class 0 Protostar in Orion
• The distance to the Orion Nebula Cluster
• A Simple Calculation in Service of Constraining the Rate of FU Orionis Outburst Events from Photometric Monitoring Surveys
• V1647 ORIONIS: Keck/Nirspec 2 MICRON Echelle Observations
• Dissection of the protostellar envelope surrounding IRAS 05173-0555 in L1634

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