Infrared Brightening in HD 166191 - A Young Star with Active Terrestrial Debris
ATel #12986; K. Su (U of Arizona), G. Rieke (U of Arizona), D. Sand (U of Arizona)
on 2 Aug 2019; 23:42 UT
Distributed as an Instant Email Notice Transients
Credential Certification: David Sand (dave.j.sand@gmail.com)
Subjects: Infra-Red, Request for Observations, Star, Variables, Young Stellar Object
We report 3.6 and 4.5 micron photometry of HD 166191 obtained with the Spitzer Space Telescope on 2019 July 15 and 19 under a Spitzer Director's Discretionary Time program. Compared to Spitzer data obtained in past years, the infrared disk fluxes at both bands have doubled, reaching to roughly 1 Jy, including the star. Our multi-year Spitzer monitoring shows that the debris production in the terrestrial zone of HD 166191 has become very active since 2018, exhibiting a large-scale, year-long flux increase similar to that observed in the prototype of variable system ID8 (Su et al. 2019) . The infrared flux increase is consistent with the aftermath of two large asteroids colliding, located at 0.5 au from the stars. Infrared spectroscopic monitoring of this active system is encouraged, particularly now at
the peak of its activity.
