ExploreNEOs. VIII. Dormant Shortperiod Comets in the NearEarth Asteroid Population
Abstract
We perform a search for dormant comets, asteroidal objects of cometary origin, in the nearEarth asteroid (NEA) population based on dynamical and physical considerations. Our study is based on albedos derived within the ExploreNEOs program and is extended by adding data from NEOWISE and the Akari asteroid catalog. We use a statistical approach to identify asteroids on orbits that resemble those of shortperiod nearEarth comets (NECs) using the Tisserand parameter with respect to Jupiter, the aphelion distance, and the minimum orbital intersection distance with respect to Jupiter. From the sample of NEAs on cometlike orbits, we select those with a geometric albedo p_{V} ≤ 0.064 as dormant comet candidates, and find that only ∼50% of NEAs on cometlike orbits also have cometlike albedos. We identify a total of 23 NEAs from our sample that are likely to be dormant shortperiod NECs and, based on a debiasing procedure applied to the cryogenic NEOWISE survey, estimate both magnitudelimited and sizelimited fractions of the NEA population that are dormant shortperiod comets. We find that 0.3%3.3% of the NEA population with H ≤ 21, and ({9}_{5}^{+2})% of the population with diameters d ≥ 1 km, are dormant shortperiod NECs.
 Publication:

The Astronomical Journal
 Pub Date:
 October 2015
 DOI:
 10.1088/00046256/150/4/106
 arXiv:
 arXiv:1508.04116
 Bibcode:
 2015AJ....150..106M
 Keywords:

 comets: general;
 minor planets;
 asteroids: general;
 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 23 pages, 2 figures, 2 tables