Kepler-1638#Planetary system

{{Starbox begin

| name = Kepler-1638

}}

{{Starbox image

| image = 250px

| caption = Constellation where Kepler-1638 is located

}}

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Cygnus{{cite web |author=Staff |title=Finding the constellation which contains given sky coordinates |url=http://djm.cc/constellation.html |date=2 August 2008 |work=DJM.cc |accessdate=16 July 2020}}

| ra = {{RA|19|41|55.76712}}

| dec = {{Dec|+48|31|27.9998}}

| appmag_v = {{val|14.769|0.206}}

}}

{{Starbox character

| engvar=en-UK

| type = main sequence star

| class = G4V{{cn|date=February 2021}}

| appmag_1_passband = J

| appmag_1 = {{val|13.550|0.023}}

| appmag_2_passband = H

| appmag_2 = {{val|13.204|0.024}}

| appmag_3_passband = K

| appmag_3 = {{val|13.138|0.035}}

| variable = Planetary transit, rotationally variable

}}

{{Starbox astrometry

| radial_v =

| prop_mo_ra = −5.092

| prop_mo_dec = +5.839

| pm_footnote =

| parallax = 0.6462

| p_error = 0.0165

| parallax_footnote =

| absmag_v =

| absmag_bol =

}}

{{Starbox detail

| source =

| mass = {{val|0.9700|0.0490|0.0590}}

| radius = {{val|0.9500|0.1660|0.0790}}

| luminosity_bolometric =

| habitable_inner =

| habitable_outer =

| gravity =

| temperature = {{val|5710.0|96.696|111.431}}

| metal_fe = {{val|-0.0100|0.1410|0.1880}}

| rotation =

| rotational_velocity =

| age_gyr = {{val|4.37|4.19|2.59}}

}}

{{Starbox catalog

| names = KOI-5856, KIC 11037818, 2MASS J19415577+4831280

}}

{{Starbox reference

|Simbad = Kepler-1638

}}

Kepler-1638 is a G-type main-sequence star located about 5,000 light years away in the constellation of Cygnus. One known exoplanet has been found orbiting the star: Kepler-1638b.{{Cite magazine|last=Burgess|first=Matt|date=2016-05-11|title=Nasa's Kepler telescope just found 1,284 exoplanets|language=en-GB|magazine=Wired UK|url=https://www.wired.co.uk/article/kepler-planets-new-exoplanets|access-date=2021-01-22|issn=1357-0978}}{{Cite web|title=Exoplanet-catalog|url=https://exoplanets.nasa.gov/exoplanet-catalog/2284/kepler-1638-b/|access-date=2021-01-22|website=Exoplanet Exploration: Planets Beyond our Solar System}}{{Cite web|last=May 2016|first=Mike Wall 11|title=1st Alien Earth Still Elusive Despite Huge Exoplanet Haul|url=https://www.space.com/32852-alien-earth-search-nasa-kepler-space-telescope.html|access-date=2021-01-22|website=Space.com|date=11 May 2016 |language=en}}As of January 2021, Kepler-1638 is the farthest star with a known exoplanet orbiting in the habitable zone.{{Cite web|title=The Habitable Exoplanets Catalog - Planetary Habitability Laboratory @ UPR Arecibo|url=http://phl.upr.edu/projects/habitable-exoplanets-catalog|access-date=2021-01-21|website=phl.upr.edu}}

Planetary system

{{Orbitbox planet begin

| table_ref =

}}

{{Orbitbox planet

| exoplanet = b

| radius_earth = {{val|1.87|0.33|0.22}}

| period = {{val|259.33683|0.01303}}

| semimajor = {{val|0.745|0.021|0.020}}

| inclination = {{val|89.9954|0.0021|0.0844}}

| mass_earth = ~4.16

}}

Kepler-1638 b is an exoplanet in orbit of its star, Kepler-1638, located in the constellation Cygnus. It was confirmed in 2016 as part of a study statistically validating hundreds of Kepler planets. Based on the parameters in the discovery paper, the planet is a super-Earth, with a radius of {{val|1.87|0.33|0.22|ul=Earth radius}}, and a predicted mass of 4.16 Earths. It has an orbit of {{val|259.337|0.013}} days in its system's habitable zone and orbits 0.745 AU from its star. It is the most distant known exoplanet that is considered potentially habitable.

However, these parameters were estimated before the first measurement of the host star's parallax was published as part of Gaia DR2 in 2018. The Gaia parallax suggests a distance of about {{convert|1548|pc|ly|lk=on|abbr=off}}, much farther than the pre-Gaia estimate of about {{convert|764|pc|ly|abbr=off}}. This revised distance results in a significantly larger estimate of the radius of the star, and thus of the planet, with a 2018 study finding a planetary radius of {{val|3.226|0.201|0.315|ul=Earth radius}}. This would make the planet an ice giant like Neptune, and thus not potentially habitable in an Earth-like sense.

References

{{reflist|refs=

{{cite web |title=Kepler-1638 |url=https://exoplanetarchive.ipac.caltech.edu/overview/Kepler-1638 |website=NASA Exoplanet Archive |access-date=2 February 2021}}

{{cite journal |title=False Positive Probabilities for all Kepler Objects of Interest: 1284 Newly Validated Planets and 428 Likely False Positives |journal=The Astrophysical Journal |first1=Timothy D. |last1=Morton |first2=Stephen T. |last2=Bryson |first3=Jeffrey L. |last3=Coughlin |first4=Jason F. |last4=Rowe |first5=Ganesh |last5=Ravichandran |first6=Erik A. |last6=Petigura |first7=Michael R. |last7=Haas |first8=Natalie M. |last8=Batalha |display-authors=5 |volume=822 |issue=2 |date=May 2016 |page=86 |doi=10.3847/0004-637X/822/2/86 |bibcode=2016ApJ...822...86M |arxiv=1605.02825|s2cid=20832201 |doi-access=free }}

{{cite journal |last1=Torres |first1=Guillermo |display-authors=etal |title=Validation of Small Kepler Transiting Planet Candidates in or near the Habitable Zone |journal=The Astronomical Journal |date=December 2017 |volume=154 |issue=6 |pages=264 |doi=10.3847/1538-3881/aa984b |arxiv=1711.01267 |bibcode=2017AJ....154..264T |s2cid=73678176 |doi-access=free }}

{{cite journal |last1=Berger |first1=Travis A. |last2=Huber |first2=Daniel |last3=Gaidos |first3=Eric |last4=van Saders |first4=Jennifer L. |title=Revised Radii of Kepler Stars and Planets Using Gaia Data Release 2 |journal=The Astrophysical Journal |date=October 2018 |volume=866 |issue=2 |pages=99 |doi=10.3847/1538-4357/aada83 |arxiv=1805.00231 |bibcode=2018ApJ...866...99B |doi-access=free }}

}}

Kepler-1638#Planetary system

Planetary system

References

See also