PH2

Last updated
PH2 / Kepler-86 [1]
PH2 b and PH2 from an exomoon.jpg
Artist's conception of PH2 and its planet, PH2b, viewed from a hypothetical moon of the planet.
Credit: Haven Giguere, Matthew Giguere/Yale
Observation data
Epoch J2000 [2]        Equinox J2000 [2]
Constellation Cygnus [3]
Right ascension 19h 19m 03.26334s [4]
Declination +51° 57′ 45.4099″ [4]
Apparent magnitude  (V)12.699±0.010 [5]
Characteristics
Evolutionary stage Main sequence
Spectral type G5V [6] [note 1]
Apparent magnitude  (J)11.501±0.023 [2]
Apparent magnitude  (H)11.182±0.03 [2]
Apparent magnitude  (K)11.116±0.022 [2]
Apparent magnitude  (B1)12.34 [2]
Apparent magnitude  (R1)12.62 [2]
B−V color index 0.072 [6]
Astrometry
Radial velocity (Rv)−17.79±1.88 [4]  km/s
Proper motion (μ)RA: 3.427  mas/yr [4]
Dec.: 16.047  mas/yr [4]
Parallax (π)2.9134 ± 0.0105  mas [4]
Distance 1,120 ± 4  ly
(343 ± 1  pc)
Absolute bolometric
magnitude  (Mbol)		5.01+0.12
−0.12 [7] [note 2]
Details [5]
Mass 0.958±0.034  M☉
Radius 0.961+0.016
−0.015  R☉
Luminosity (bolometric)0.79+0.09
−0.08 [8]   L☉
Surface gravity (log g)4.45±0.02  cgs
Temperature 5711+60
−59  K
Metallicity [Fe/H]−0.03±0.04  dex
Rotation 22.6 days
Rotational velocity (v sin i)1.43±0.78 [8]  km/s
Other designations
PH2, Kepler-86, KOI-3663, KIC  12735740, TIC  416279912, 2MASS J19190326+5157453 [9]
Database references
SIMBAD data
KIC data

PH2, also known as Kepler-86, [1] or KIC 12735740 (2MASS J19190326+5157453), is a G-type star [8] [note 1] 1,120 light-years (340 parsecs ) distant [4] within the constellation Cygnus. [3] Roughly the size and temperature [6] of the Sun, [10] PH2 gained prominence when it was known to be the host of one of 42 planet candidates detected by the Planet Hunters citizen science project in its second data release. [11] The candidate orbiting around PH2, known as PH2 b, had been determined to have a spurious detection probability of only 0.08%, thus effectively confirming its existence as a planet. [8]

Contents

Located in its parent star's habitable zone, PH2 b (or Kepler-86b [1] ) is a Jupiter-size gas giant which could in theory host a natural satellite suitable for hosting life. [11] The report of the confirmed detection of PH2 b was submitted on January 3, 2013. [8] It was discovered by amateur Pole Rafał Herszkowicz using his laptop and access to the Internet project with data from the Kepler space observatory. [12]

History of detection

The Kepler search volume, in the context of the Milky Way Galaxy. LombergA1024.jpg
The Kepler search volume, in the context of the Milky Way Galaxy.

PH2 b was detected, along with 42 other planet candidates, in archival data from Kepler by the Planet Hunters project, in which human volunteers analyze the light curves of Kepler target stars, searching for planetary transit signals which may be missed by computer programs. [8] Previous work by Planet Hunters helped to confirm the existence of PH1b, a Neptune-mass planet within a four-star system.

All of the candidates in the study, including PH2 b, were identified by citizen scientists Abe J. Hoekstra, Thomas Lee Jacobs, Daryll LaCourse, Hans Martin Schwengler, Rafał Herszkowicz and Mike Chopin among others, with the help of Yale University astronomers. [8] In addition to PH2 b itself, twenty other planet candidates were found which are located in the habitable zones of their host stars; however, these have a relatively high probability of spurious detection and may well come from non-planetary sources. [8]

Although the planet's initial detection was made using Kepler data, PH2's stellar spectra, required to rule out background stars or faint companions with planets as sources for the observed transits, were collected using the HIRES instrument at the W. M. Keck Observatory. [8] Results of observations confirmed the existence of PH2 b with "99.9 percent confidence." [8] [11]

Planetary system

PH2 is host to one confirmed planet, PH2 b, orbiting with a period of about 282 days, placing it and any possible moons in the habitable zone. [11] The temperature in the upper atmosphere of the planet could range from 185 K (−88 °C; −127 °F) to 303 K (30 °C; 86 °F). [8] A moon of PH2 b would likely have "a rocky core, plus a greenhouse atmosphere of some sort that could have liquid water on its surface" in the words of the researchers, thus further improving its prospects for habitability. [11]

In 2019, the mass of the planet was measured by radial velocity, showing it to be close in mass to Saturn. [5]

The PH2 planetary system [5]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b108.81+29.79
−32.29  M🜨 		0.824+0.019
−0.017		282.52540+0.00010
−0.00011		0.280+0.121
−0.133		89.915+0.020
−0.022 ° 		9.49±0.16  R🜨

See also

Notes

Related Research Articles

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<span class="mw-page-title-main">Kepler-70</span> Star in the constellation Cygnus

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<span class="mw-page-title-main">Kepler-42</span> Red dwarf star in the constellation Cygnus

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Kepler-1520 is a K-type main-sequence star located in the constellation Cygnus. The star is particularly important, as measurements taken by the Kepler spacecraft indicate that the variations in the star's light curve cover a range from about 0.2% to 1.3% of the star's light being blocked. This indicates that there may be a rapidly disintegrating planet, a prediction not yet conclusively confirmed, in orbit around the star, losing mass at a rate of 1 Earth mass every billion years. The planet itself is about 0.1 Earth masses, or just twice the mass of Mercury, and is expected to disintegrate in about 100-200 million years. The planet orbits its star in just 15.7 hours, at a distance only two stellar diameters away from the star's surface, and has an estimated effective temperature of about 2255 K. The orbital period of the planet is one of the shortest ever detected in the history of the extrasolar planet search. In 2016, the planet was confirmed as part of a data release by the Kepler spacecraft.

<span class="mw-page-title-main">Planet Hunters</span> Citizen science project to find exoplanets

Planet Hunters is a citizen science project to find exoplanets using human eyes. It does this by having users analyze data from the NASA Kepler space telescope and the NASA Transiting Exoplanet Survey Satellite. It was launched by a team led by Debra Fischer at Yale University, as part of the Zooniverse project.

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<span class="mw-page-title-main">Kepler-69</span> Star in the constellation Cygnus

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<span class="mw-page-title-main">Kepler-186</span> Star in the constellation Cygnus

Kepler-186 is a main-sequence M1-type dwarf star, located 178.5 parsecs away in the constellation of Cygnus. The star is slightly cooler than the sun, with roughly half its metallicity. It is known to have five planets, including the first Earth-sized world discovered in the habitable zone: Kepler-186f. The star hosts four other planets discovered so far, though they all orbit interior to the habitable zone.

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<span class="mw-page-title-main">Kepler-452</span> G-type main-sequence star in the constellation Cygnus

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Kepler-1229 is a red dwarf star located about 870 light-years (270 pc) away from the Earth in the constellation of Cygnus. It is known to host a super-Earth exoplanet within its habitable zone, Kepler-1229b, which was discovered in 2016.

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References

  1. 1 2 3 Staff (September 25, 2013). "Congratulations! MT @planethunters: Our 2nd confirmed planet PH2 b has received the alternate Kepler designation of Kepler-86b". inagist/@NASAKepler. Archived from the original on September 27, 2013. Retrieved September 25, 2013.
  2. 1 2 3 4 5 6 7 "Gator Cone Search Result". The Two Micron All Sky Survey at IPAC. NASA/IPAC. Retrieved January 12, 2013.[ permanent dead link ]
  3. 1 2 "VizieR Detailed Page". VizieR. Harvard-Smithsonian Center for Astrophysics . Retrieved January 12, 2013.
  4. 1 2 3 4 5 6 7 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID   244398875. Gaia DR3 record for this source at VizieR.
  5. 1 2 3 4 Dubber, Sophie C.; Mortier, Annelies; et al. (December 2019). "Using HARPS-N to characterize the long-period planets in the PH-2 and Kepler-103 systems". Monthly Notices of the Royal Astronomical Society . 490 (4): 5103–5121. arXiv: 1910.03518 . Bibcode:2019MNRAS.490.5103D. doi:10.1093/mnras/stz2856.
  6. 1 2 3 "Kepler Data Search Results". MAST. Space Telescope Science Institute . Retrieved January 12, 2013.
  7. ↑ Mamajek, Eric (December 30, 2012). "Basic Astronomical Data for the Sun (BADS)". University of Rochester . Retrieved January 12, 2013.
  8. 1 2 3 4 5 6 7 8 9 10 11 Wang, Ji; Fischer, Debra A.; et al. (October 2013). "Planet Hunters. V. A Confirmed Jupiter-size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data". The Astrophysical Journal . 776 (1): 10. arXiv: 1301.0644 . Bibcode:2013ApJ...776...10W. doi:10.1088/0004-637X/776/1/10. S2CID   119241051.
  9. ↑ "Kepler-86". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 23 April 2023.
  10. ↑ Williams, David R. (March 2, 2012). "Sun Fact Sheet". National Aeronautics and Space Administration. Retrieved January 12, 2013.
  11. 1 2 3 4 5 Howell, Elizabeth (11 January 2013). "Amateur Astronomers Discover 42 Alien Planets". Space.com . Space.com. Retrieved January 12, 2013.
  12. ↑ "Polski informatyk Rafał Herszkowicz odkrył nową planete PH2b | Forsal.pl - Giełda, Waluty, Finanse" (in Polish). Forsal. 2013-03-27. Retrieved 2013-07-12.

Footnotes

  1. 1 2 The stellar temperature is 5629 K, roughly the same as the G2V Sun's 5778 K.
  2. ↑ Calculated based on -2.5 log10 of luminosity differences.
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