14h12m37.5330s, +04° 03′ 36.1177″| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 14h12m 37.53311s[1] |
| Declination | +04° 03′ 36.1166″[1] |
| Apparent magnitude (V) | 11.76[2] |
| Characteristics | |
| Spectral type | K1V |
| Astrometry | |
| Radial velocity (Rv) | 14.10±0.39[1] km/s |
| Proper motion (μ) | RA: 37.735 mas/yr[1] Dec.: -142.816 mas/yr[1] |
| Parallax (π) | 6.9985 ± 0.0204 mas[1] |
| Distance | 466 ± 1 ly (142.9 ± 0.4 pc) |
| Details[3] | |
| Mass | 0.81 M☉ |
| Radius | 0.78 R☉ |
| Temperature | 5079±88 K |
| Metallicity | -0.04±0.08[4] |
| Rotational velocity (v sin i) | 1.8 km/s |
| Other designations | |
Guahayona, Gaia DR2 3668036348641580288, TYC 320-1027-1, GSC 0320-01027, 2MASS J14123753+0403359[2] | |
| Database references | |
| SIMBAD | data |
HAT-P-26 is a K-type main-sequence star about 466 light-years (143 parsecs) away. A survey in 2015 did not find any stellar companions in orbit around it,[5] although a red dwarf companion with a temperature 4000+100
−350 K is suspected on wide orbit.[6]
The designation HAT-P-26 indicates that this was the 26th star found to have a planet by the HATNet Project.
In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project.[7] The approved names, proposed by a team from Puerto Rico, were announced in June 2023. HAT-P-26 is named Guahayona and its planet is named Guataubá, after figures from Taíno mythology.[8]
In 2010 a transiting hot Neptune like planet was detected.[4] The transiting planet HAT-P-26b was detected by the HATNet Project using telescopes located in Hawaii and Arizona. The planet is likely formed by pebble accretion mechanism.[9]
The transmission spectrum of HAT-P-26b was taken in 2015, with the best fit favouring either a cloudless atmosphere or an atmosphere with a low-lying cloud deck.[10] The atmospheric composition of the planet was measured in 2019, and a water vapor volume fraction of 1.5+2.1
−0.9% was detected. HAT-P-26 is carbon depleted, with a C/O ratio constrained to less than 0.33. Also, the planet's atmosphere contains light metal hydrides.[11] The measured planetary temperature is equal to 563+58
−54 K.
In 2019, a transit timing variation analysis of HAT-P-26b indicated the possible presence of a second planet in the system on a wide, 1141-days orbit.[12]
In 2023, the atmosphere of the planet was confirmed to contain 12±2% steam at 590+20
−30K.[13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Guataubá | >0.0585±0.00717 MJ | 0.0479±0.0006 | 4.234516±0.000015 | 0.124±0.060 | 88.6±0.9° | 0.5647±0.0517 RJ |
| c (unconfirmed) | — | — | 1141 | — | — | — |
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