Kepler-1625b
| Discovery | |
|---|---|
Kepler Mission) | |
| Orbital characteristics | |
| 0.98 ± 0.14 AU | |
| Eccentricity | - |
| 287.378949 d | |
| Inclination | 89.97 ± 0.02 |
| Known satellites | Kepler-1625b I? |
| Star | Kepler-1625 |
| Physical characteristics | |
| 1.18+0.18 −0.32 RJ [1] | |
| Mass | ≤11.60 MJ[2] |
Kepler-1625b is a super-Jupiter
Kepler Mission.[6][7] Further evidence for a Neptunian moon was found the following year using the Hubble Space Telescope, where two independent lines of evidence constrained the mass and radius to be Neptune-like.[4] The mass-signature has been independently recovered by two other teams.[8][9] However, the radius-signature was independently recovered by one of the teams[9] but not the other.[8] The original discovery team later showed that this latter study appears affected by systematic error sources that may have influenced its findings.[10]
Characteristics
Mass and radius
Kepler-1625b is a
Jupiter masses. Any more massive and Kepler-1625b would be a brown dwarf. However, this mass value only corresponds to a 3-sigma upper limit and the mass of the planet remains undetected at this time.[2]
Orbit and temperature
Unlike the gas giants in our Solar System, Kepler-1625b orbits much closer, slightly closer than the orbital radius as the Earth around the Sun.years; 9.43 months) to orbit Kepler-1625, as a result of the star's slightly greater mass than the Sun. Kepler-1625b receives 2.6 times more insolation than the Earth,[4] meaning it lies at the inner edge of the habitable zone.[11] However, as the planet has likely no solid surface, bodies of liquid water are impossible.
Candidate exomoon
In July 2017, researchers found signs of a
In October 2018, researchers using the
Transit Timing Variation signature that indicated an approximately Neptune-mass moon, and an additional photometric dip that indicated a Neptune-radius moon.[4] The relative phasing of the two signatures was also consistent with that which a real moon would cause, with the effects in anti-phase.[4] The study concluded that the exomoon hypothesis is the simplest and best explanation for the available observations, though warned that it is difficult to assign a precise probability to its reality and urged follow-up analyses.[12][4]
In February 2019, a reanalysis of the combined Kepler and Hubble observations recovered both a moon-like dip and similar
transit timing variation signal.[9] However, the authors suggested that the data could also be explained by an inclined hot-Jupiter in the same system that has gone previously undetected, which could be tested using future Doppler spectroscopy radial velocity measurements. A second independent reanalysis was published in April 2019, which recovered one of the two lines of evidence, the transit timing variation, but the not the second, the moon-like dip.[8] The original discovery team responded to this soon after, finding that this re-analysis exhibits stronger systematics in their reduction which may be responsible for their differing conclusion.[10]
References
- ^ Heller, René. "The nature of the giant exomoon candidate Kepler-1625 b-i". Astronomy & Astrophysics. EDP Sciences. Retrieved 20 February 2025.
- ^ S2CID 210942758.
- S2CID 244895570. Retrieved April 1, 2022.
- ^ PMID 30306135.
- ^ "Exoplanet Exploration: Planets Beyond our Solar System". Exoplanet Exploration: Planets Beyond our Solar System. Archived from the original on October 3, 2018.
- ^ a b Crane, Leah (July 27, 2017). "First exomoon might have been spotted 4000 light years away". NewScientist. Retrieved April 1, 2022.
- ^ S2CID 118911978.
- ^ S2CID 129945202.
- ^ S2CID 119311103. Retrieved April 1, 2022.
- ^ S2CID 135465103.
- S2CID 27805994.
- ^ a b Drake, Nadia (3 October 2018). "Weird giant may be the first known alien moon - Evidence is mounting that a world the size of Neptune could be orbiting a giant planet far, far away". National Geographic Society. Archived from the original on October 3, 2018. Retrieved 4 October 2018.
- ^ "Kelpler-1625b-I". Extrasolar Planets Encyclopaedia. 15 July 2019. Archived from the original on 5 October 2018. Retrieved 14 December 2020.