Astronomy:HD 137010 b
| File:300px Artistic representation of exoplanet candidate HD 137010 b | |
| Discovery | |
|---|---|
| Discovered by | Kepler (K2)[1] |
| Discovery date | January 27, 2026 |
| Transit | |
| Orbital characteristics | |
| 0.88+0.3 −0.1 astronomical unit|AU | |
| Eccentricity | 0 |
| Orbital period | 355.0+200.0 −59.0 d |
| Inclination | >89.82+0.05 −0.03 |
| Star | HD 137010 |
| Physical characteristics | |
| Mean radius | 1.06+0.06 −0.05 R🜨 |
| Physics | 205.0 ± 25.0 K (−68.1 ± 25.0 °C; −90.7 ± 45.0 °F) |
HD 137010 b is an exoplanet candidate detected by the Kepler's K2 mission of NASA.[2] Orbiting the K-type dwarf star HD 137010 in the constellation of Libra,[3] it is located approximately 146 light-years from the Solar System.[2] The candidate was identified from a single 10-hour transit event observed during K2 Campaign 15 in 2017, suggesting an orbital period of about 355 days, nearly identical to that of Earth.[4] With a radius of 1.06 times that of Earth, it is classified as a potential Super-Earth or Earth analog, likely rocky in composition.[5] Due to its host star's lower luminosity, HD 137010 b receives only about 29% of the incident flux that Earth does, placing it near the outer edge of the system's habitable zone with an estimated equilibrium temperature around −68°C (−90°F), potentially colder than Mars.[2][5] Confirmation as a genuine exoplanet requires additional transits or alternative observations, which may be pursued with missions like TESS or CHEOPS.[4][6][7]
File:Concept animation of exoplanet candidate HD 137010 b.webm
Discovery and observation
HD 137010 b was first flagged as a potential planet candidate by citizen scientists participating in the Planet Hunters project, which sifts through data from NASA's Kepler Space Telescope.[4] The signal was overlooked by automated detection algorithms, which prioritize multiple transits, until astrophysicist Alexander Venner re-examined the K2 Campaign 15 data during his Ph.D. research at the University of Southern Queensland.[4] The single transit, lasting approximately 10 hours, was recorded in 2017 and indicated a small planetary body eclipsing its host star.[2] The discovery team, including collaborators from the Max Planck Institute for Astronomy, ruled out false positives such as stellar binaries through detailed modeling.[4][8]
The findings were published on January 27, 2026, in The Astrophysical Journal Letters under the title "A Cool Earth-sized Planet Candidate Transiting a Tenth Magnitude K-dwarf From K2".[8][5][2] Venner presented the results at the Rocky Worlds conference, highlighting the planet's Earth-like orbital architecture despite the single-event detection.[4] Follow-up observations are challenging due to the long orbital period, which reduces the likelihood of repeated transits within a single mission's timeframe, proposed strategies include radial velocity measurements or targeted monitoring with the James Webb Space Telescope (JWST).[2]
Host star
HD 137010 is a K-type dwarf with a visual magnitude of 10.1, making it observable with amateur telescopes.[5] The star has an effective temperature approximately 1,000 K cooler than the Sun's 5,772 K, resulting in about 70% of the Sun's mass and radius, and correspondingly lower luminosity.[2] This dimmer output shifts the habitable zone inward compared to solar-type systems, influencing the thermal environment of orbiting planets like HD 137010 b.[4]
Characteristics
HD 137010 b has an estimated radius of 1.06+0.06
−0.05 R🜨, placing it in the range of small, potentially terrestrial worlds.[5] Its orbital period is 355.0+200.0
−59.0 d, with a semi-major axis of 0.88+0.3
−0.1 astronomical unit|AU, yielding an nearly circular orbit (eccentricity ≈ 0) and near-edge-on inclination for transit visibility.[5] The planet receives an incident bolometric flux of 0.29+0.11
−0.13 times that incident on Earth (F⊕), leading to a blackbody equilibrium temperature of roughly −68 °C, though actual surface conditions would depend on atmospheric properties.[2][5] No mass or density measurements are available, but its size suggests a rocky composition similar to Earth.[9]
Habitability
Positioned at the outer boundary of its star's habitable zone as defined by Kopparapu et al. (2013), HD 137010 b may support liquid water under a thick, greenhouse-enhanced atmosphere rich in CO2, potentially resembling a super-Venus or early Martian environment.[5][2] Atmospheric models indicate a 40% probability of residing in the conservative habitable zone and 51% in the optimistic zone, but a comparable chance of being entirely too cold for surface habitability without extreme greenhouse forcing.[2] Its proximity to a relatively bright host star facilitates potential spectroscopic characterization of any atmosphere using future observatories like JWST, which could detect biosignatures from subsurface oceans or geothermal activity if present.[4] However, as an unconfirmed candidate, these assessments remain speculative, and the planet's true nature whether a frozen ice world or marginally temperate awaits validation.[10]
References
- ↑ Martin, Pierre-Yves (2026). "Planet HD 137010 b" (in en). https://exoplanet.eu/catalog/hd_137010_b--11844/.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 "Discovery Alert: An Ice-Cold Earth? - NASA Science" (in en-US). 2026-01-27. https://science.nasa.gov/universe/exoplanets/discovery-alert-an-ice-cold-earth/.
- ↑ "HD 137010 | NASA Exoplanet Archive". https://exoplanetarchive.ipac.caltech.edu/overview/HD%20137010.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 "Earth-size planet spotted with yearlong orbit" (in en). Science. https://www.science.org/content/article/earth-size-planet-spotted-yearlong-orbit. Retrieved 2026-02-08.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Cowing, Keith (2026-01-28). "A Cool Earth-sized Planet Candidate Transiting a Tenth Magnitude K-dwarf From K2" (in en-US). https://astrobiology.com/2026/01/a-cool-earth-sized-planet-candidate-transiting-a-tenth-magnitude-k-dwarf-from-k2.html.
- ↑ Lu, Donna (2026-01-29). "A potentially habitable new planet has been discovered 146 light-years away – but it may be -70C" (in en-GB). The Guardian. ISSN 0261-3077. https://www.theguardian.com/science/2026/jan/29/a-potentially-habitable-new-planet-has-been-discovered-146-light-years-awfrom-earth-but-it-may-be--70c.
- ↑ Gough, Evan (2026-01-29). "Finding A Frozen Earth In Old Data" (in en). https://www.universetoday.com/articles/finding-a-frozen-earth-in-old-data.
- ↑ 8.0 8.1 Venner, Alexander; Vanderburg, Andrew; Huang, Chelsea X.; Dholakia, Shishir; Schwengeler, Hans Martin; Howell, Steve B.; Wittenmyer, Robert A.; Kristiansen, Martti H. et al. (2026-02-01). "A Cool Earth-sized Planet Candidate Transiting a Tenth Magnitude K-dwarf From K2". The Astrophysical Journal Letters 997 (2): L38. doi:10.3847/2041-8213/adf06f. ISSN 2041-8205. Bibcode: 2026ApJ...997L..38V.
- ↑ Staff, ScienceAlert (2026-02-06). "Scientists Reveal a Frozen Bizarro Earth Only 150 Light-Years Away" (in en-US). https://www.sciencealert.com/scientists-reveal-a-frozen-bizarro-earth-only-150-light-years-away.
- ↑ Howlett, Joseph. "Another Earth or a blip in the data? We may never find out" (in en). https://www.scientificamerican.com/article/another-earth-or-a-blip-in-the-data-we-may-never-find-out/.
External links
- Anton Petrov (8 February 2026). NASA Missed This! Citizen Scientists Just Found an Earth Like Planet. Video on YouTube.
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