New Kepler Potential Planet Transit Signals
Post date: Nov 04, 2013 4:0:29 PM
The NASA Kepler team released a revised global list of 16,285 potential planet transit signals (formally known as Threshold-Crossing Events or TCE) from quarters one to sixteen, the four years of operation of Kepler (Table 1). This list already includes most of the 3,602 Kepler Objects of interest (KOI) with 170 Kepler Confirmed Planets.
Additional analysis is necessary to confirm the planetary nature of the over 12,000 remaining TCE objects. Many of these transits signals are expected to be false alarms, specially for long periods objects such as those orbiting within the habitable zone (HZ).
Nearly 1,500 TCE objects match our standard criteria for potentially habitable planets (planet size 0.4 — 2.6 Earth radii orbiting within the empirical HZ), but only about 20% of them might turn out to be real planets, still a large number. Nevertheless, this analysis provides some upper limits to interesting objects in the Kepler TCE sample (Table 2).
Table 1. Summary statistics of some planetary and stellar characteristics of the new 16,285 TCE list.
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Property MIN AVG MAX Count
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Planet Radius (EU): 0.00 15.53 5312.00 16285
Planet Period (days): 0.50 197.33 707.28 16285
Planet Semi-Major Axis (AU): 0.0101 0.5349 2.3200 16285
Planet Temperature(K): 63.10 875.85 14200.00 16285
Star Mass (SU): 0.09 1.06 3.71 16285
Star Radius (SU): 0.12 4.18 219.50 16285
Star Temperature (K): 2661.00 5715.10 15896.00 16285
Star Luminosity (SU): 0.0006 48.2446 14036.8495 16285
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EU = earth units, SU = solar units
Table 2. Basic analysis of the TCE objects.
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Habitable Exoplanets Catalog (HEC) Statistics
Data Source: NASA Kepler Threshold Crossing Events (TCE)
[Nov 4, 2013] Planetary Habitability Laboratory (phl.upr.edu)
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Stellar Systems 9743
Exoplanets 16285
Exoplanets in the Hot Zone 10982 (67.4%)
Exoplanets in the Warm 'Habitable' Zone 3646 (22.4%)
Exoplanets in the Cold Zone 1657 (10.2%)
Unclassified 0 ( 0.0%)
Potential Habitable Exoplanets 1486 ( 9.1%)
Expected Potential Habitable Exomoons 185 ( 1.1%)
Eta Earth 15.3 %
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Number of Multiple Systems
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1 2 3 4 5 6 7 8 9 10
6520 1832 537 292 228 204 93 30 3 4
66.9 18.8 5.5 3.0 2.3 2.1 1.0 0.3 <0.1 <0.1
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Planetary Class
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Mercurian Subterran Terran Superterran Neptunian Jovian
42 327 1382 5766 5063 3355
0.3 2.0 8.5 35.4 31.1 20.6
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Hot Zone
Category Count Percent
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Mercurians 19 0.1
Subterrans 274 1.7
Terrans 1123 6.9
Superterrans 3664 22.5
Neptunians 2695 16.5
Jovians 2858 17.5
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Warm 'Habitable' Zone
Category Count Percent
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Mercurians 3 0.0
Subterrans 29 0.2
Terrans 117 0.7
Superterrans 1340 8.2
Neptunians 1760 10.8
Jovians 396 2.4
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Cold Zone
Category Count Percent
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Mercurians 20 0.1
Subterrans 24 0.1
Terrans 142 0.9
Superterrans 762 4.7
Neptunians 608 3.7
Jovians 101 0.6
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References