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Title: KOI-2700b—a planet candidate with dusty effluents on a 22 hr orbit

Kepler planet candidate KOI-2700b (KIC 8639908b), with an orbital period of 21.84 hr, exhibits a distinctly asymmetric transit profile, likely indicative of the emission of dusty effluents, and reminiscent of KIC 1255b. The host star has T {sub eff} = 4435 K, M ≅ 0.63 M {sub ☉}, and R ≅ 0.57 R {sub ☉}, comparable to the parameters ascribed to KIC 12557548. The transit egress can be followed for ∼25% of the orbital period and, if interpreted as extinction from a dusty comet-like tail, indicates a long lifetime for the dust grains of more than a day. We present a semiphysical model for the dust tail attenuation and fit for the physical parameters contained in that expression. The transit is not sufficiently deep to allow for a study of the transit-to-transit variations, as is the case for KIC 1255b; however, it is clear that the transit depth is slowly monotonically decreasing by a factor of ∼2 over the duration of the Kepler mission. We infer a mass-loss rate in dust from the planet of ∼2 lunar masses per Gyr. The existence of a second star hosting a planet with a dusty comet-like tail would help to show that suchmore » objects may be more common and less exotic than originally thought. According to current models, only quite small planets with M{sub p} ≲ 0.03 M {sub ⊕} are likely to release a detectable quantity of dust. Thus, any 'normal-looking' transit that is inferred to arise from a rocky planet of radius greater than ∼1/2 R {sub ⊕} should not exhibit any hint of a dusty tail. Conversely, if one detects an asymmetric transit due to a dusty tail, then it will be very difficult to detect the hard body of the planet within the transit because, by necessity, the planet must be quite small (i.e., ≲ 0.3 R {sub ⊕}).« less
Authors:
;  [1] ; ;  [2] ;  [3] ;  [4]
  1. Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
  2. BAER Institute/NASA Ames Research Center, M/S 244-30, Moffett Field, Mountain View, CA 94035 (United States)
  3. Visidyne, Inc., 111 South Bedford St., Suite 103, Burlington, MA 01803 (United States)
  4. SETI Institute, 189 Bernardo Ave, Suite 100 Mountain View, CA 94043 (United States)
Publication Date:
OSTI Identifier:
22351505
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 784; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; ATTENUATION; COMPARATIVE EVALUATIONS; DETECTION; DUSTS; EMISSION; LIFETIME; MASS TRANSFER; PLANETS; SATELLITES; STARS; STELLAR WINDS