NOAO >   Observing Info >   Approved Programs >   2018A-0197

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Program Information for 2018A-0197


PI: Matthew M Knight, U. of Maryland, mmk8a@astro.umd.edu
Address: Department of Astronomy, 1113 Physical Sciences Complex, Bldg 415, College Park, MD 20742 USA

CoI: Michael Kelley, U. of Maryland
CoI: Colin Snodgrass, The Open University (UK)
CoI: Alan Fitzsimmons, Queen's U. Belfast

Title: Roasting small bodies: Testing the effects of low perihelion distance on comets and asteroids

Abstract: Our recent investigation of ``sunskirting'' comet 322P/SOHO~1 (perihelion distance, $q$, of 0.05 AU) revealed a confusing picture: 322P has a cometary orbit, is active near perihelion but inactive near 1 AU, and has color, albedo, and rotation period that suggest it is an asteroid. In order to determine if 322P's properties are intrinsic or evolutionary due to repeated close approaches to the Sun, we seek to better understand the population of low-$q$ objects. We propose to study comet 96P/Machholz~1, which has the lowest perihelion distance (0.12 AU) of any periodic comet discovered from Earth, making it critical for investigating differences between ``normal'' comets and those seen only by {it SOHO}. Our 2017 observations of 96P found a rotation period near the rotational breakup limit. Follow-up observations with Goodman on SOAR in 2018A will allow us to test if the period has changed due to the recent perihelion passage (October 2017) and to further characterize its nucleus properties. We will also acquire snapshot color observations of two low-$q$ asteroids for comparison with 322P.

Program Type: Standard/Solar System

Scheduled Nights:
Run 1 (2018A):  SOAR/Goodman -- 1n on Jun 24 2018
Run 2 (2018A):  SOAR/Goodman -- 0.5n on Jul 10 2018


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



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