L 98-59

Last updated
L 98-59
Observation data
Epoch J2000       Equinox J2000
Constellation Volans
Right ascension 08h 18m 07.62144s [1]
Declination −68° 18′ 46.8054″ [1]
Apparent magnitude  (V)11.69±0.05 [2]
Characteristics
Evolutionary stage Red dwarf (main sequence)
Spectral type M3V [3]
B−V colour index +1.53 [2]
R−I colour index +1.28 [2]
Variable type None
Astrometry
Radial velocity (Rv)−6.10±0.19 [1]  km/s
Proper motion (μ)RA: 94.794(18)  mas/yr [1]
Dec.: −340.084(20)  mas/yr [1]
Parallax (π)94.2664 ± 0.0155  mas [1]
Distance 34.599 ± 0.006  ly
(10.608 ± 0.002  pc)
Details [3]
Mass 0.273±0.030  M☉
Radius 0.303+0.026
−0.023  R☉
Luminosity (bolometric)0.01128±0.00042  L☉
Surface gravity (log g)4.86±0.13  cgs
Temperature 3415±135  K
Metallicity [Fe/H]−0.46±0.26  dex
Rotation 80.9+5.0
−5.3  d
Age >800  Myr
Other designations
2MASS J08180763-6818468, TOI-175, TYC 9193-2365-1, Gaia DR2 5271055243163629056
Database references
SIMBAD data

L 98-59 (TOI-175, TIC 307210830) is a bright M dwarf star, located in the constellation of Volans, at a distance of 10.608 parsecs (34.60 light-years ), as measured by Gaia. [4]

Contents

Broadband photometry shows that it is an M3 dwarf star with three confirmed terrestrial-sized planets in transit, which were announced in March 2019 by TESS, [5] as well as a fourth non-transiting planet and fifth candidate. [6]

In August 2021, new evidence was announced for a fifth, potentially habitable planet, labeled L 98-59 f. Though still unconfirmed, [6] this planet is believed to have 2.46 times Earth's mass, and an orbital period of 23.15 days. [7] [8]

Planetary system

The three inner planets of L 98-59 were discovered in 2019 by TESS. [5] The potential super-Venus planet L 98-59 e was discovered in 2021, along with potentially habitable (located in the middle of the habitable zone) super-Earth candidate L 98-59 f. [3] In September 2021, suggested tests of the abilities of the Hubble Space Telescope and the upcoming James Webb Space Telescope to detect and describe the atmospheric features of the three inner planets were reported. [9]

The two innermost planets, L 98-59 b and c, as well as L 98-59 e are possibly hot rocky worlds. L 98-59 d has a low density, indicating large amounts of water, potentially making up as much as 30% of its entire mass. It may therefore be covered in a deep global ocean. [7] Hubble observations of the three transiting planets in 2022 have found no clear evidence of atmospheres, with high mean molecular weight atmospheres, cloudy or hazy atmospheres, or no atmospheres being consistent with the observed flat spectra. [10] [11] [12] One study found some evidence of an atmosphere on L 98-59 c, which has yet to be confirmed as of 2023. [13]

The L 98-59 planetary system [3]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b 0.40+0.16
−0.15  M🜨 		0.02191+0.00080
−0.00084		2.2531136+0.0000012
−0.0000015		0.103+0.117
−0.045		87.71+1.16
−0.44 ° 		0.85+0.061
−0.047  R🜨
c2.22+0.26
−0.25  M🜨 		0.0304+0.0011
−0.0012		3.6906777+0.0000016
−0.0000026		0.103+0.045
−0.058		88.11+0.36
−0.16 ° 		1.385+0.095
−0.075  R🜨
d1.94±0.28  M🜨 0.0486+0.0018
−0.0019		7.4507245+0.0000081
−0.0000046		0.074+0.057
−0.046		88.449+0.058
−0.111 ° 		1.521+0.119
−0.098  R🜨
e≥3.06+0.33
−0.37  M🜨 		0.0717+0.0060
−0.0048		12.796+0.020
−0.019		0.128+0.108
−0.076		——
f(unconfirmed)≥2.46+0.66
−0.82 M🜨 		0.1034+0.0042
−0.0044		23.15+0.60
−0.17		0.21+0.17
−0.11		——
Artist's impression of the L 98-59 system, compared to the inner Solar System. Distances are not to scale. Comparison of the L 98-59 exoplanet system with the inner Solar System.jpg
Artist's impression of the L 98-59 system, compared to the inner Solar System. Distances are not to scale.

See also

Related Research Articles

<span class="mw-page-title-main">HD 219134</span> Star in the constellation Cassiopeia

HD 219134 is a main-sequence star in the constellation of Cassiopeia. It is smaller and less luminous than the Sun, with a spectral class of K3V, which makes it an orange-hued star. HD 219134 is relatively close to our system, with an estimated distance of 21.34 light years. This star is close to the limit of apparent magnitude that can still be seen by the unaided eye. The limit is considered to be magnitude 6 for most observers. This star has a magnitude 9.4 optical companion at an angular separation of 106.6 arcseconds.

Pi Mensae, also known as HD 39091, is a yellow dwarf star in the constellation of Mensa. This star has a high proper motion. The apparent magnitude is 5.67, which can be visible to the naked eye in exceptionally dark, clear skies. It is nearly 60 light-years away. The star is slightly larger than the Sun in terms of mass, size, luminosity, temperature and metallicity, and is about 730 million years younger. It hosts three known planets.

HD 106515 is a binary star in the constellation of Virgo.

<span class="mw-page-title-main">Gliese 180</span> Star in the constellation Eridanus

Gliese 180, is a small red dwarf star in the equatorial constellation of Eridanus. It is invisible to the naked eye with an apparent visual magnitude of 10.9. The star is located at a distance of 39 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −14.6 km/s. It has a high proper motion, traversing the sky at the rate of 0.765 arcseconds per year.

<span class="mw-page-title-main">LHS 1140</span> Star in the constellation Cetus

LHS 1140 is a red dwarf in the constellation of Cetus. Based on stellar parallax measurement, it is 48.8 light-years away from the Sun. 'LHS' refers to the Luyten Half-Second Catalogue of stars with proper motions exceeding half a second of arc annually. The star is over 5 billion years old and has only about 18% the mass of the Sun and 21% of its radius. LHS 1140's rotational period is 130 days. No flares have been observed.

GJ 9827 is a star in the constellation of Pisces. It is a K-type main-sequence star with an apparent magnitude of 10.250. It is 97 light-years away, based on parallax.

GJ 1132 is a small red dwarf star 41.1 light-years away from Earth in the constellation Vela. In 2015, it was revealed to have a hot rocky Earth-sized planet orbiting it every 1.6 days. In 2018, a second planet and a potential third were revealed.

WASP-49 is a yellow dwarf main-sequence star. Its surface temperature is 5600 K. WASP-49 is depleted of heavy elements relative to Sun, with metallicity Fe/H index of -0.23, meaning it has an abundance of iron 59% of the Sun's level.

<span class="mw-page-title-main">LTT 1445</span> Star system in the constellation Eridanus

LTT 1445 is a triple M-dwarf system 22.4 light-years distant in the constellation Eridanus. The primary LTT 1445 A hosts two exoplanets—one discovered in 2019 that transits the star every 5.36 days, and another found in 2021 that transits the star every 3.12 days, close to a 12:7 resonance. As of August 2019 it is the second closest transiting exoplanet system discovered, with the closest being HD 219134 bc.

WASP-29 is a binary star system in the constellation of Phoenix. The primary star is an orange main sequence star. Its comoving companion, a red dwarf star, was discovered in 2021. The star system kinematically belongs to the thin disk of the Milky Way.

HAT-P-41 is a binary star system. Its primary is a F-type main-sequence star. Its surface temperature is 6390±100 K. compared to the Sun, HAT-P-41 is enriched in heavy elements, with a metallicity Fe/H index of 0.21±0.10, but is much younger at an age of 2.2±0.4 billion years.

<span class="mw-page-title-main">L 98-59 b</span> Terrestrial planet orbiting L 98-59

L 98-59 b is an exoplanet having a size between that of the Earth and Mars and a mass only half that of Venus. It orbits L 98-59, a red dwarf 35 light-years away in the constellation Volans. There are at least 3 other planets in the system: L 98-59 c, d, e, and the unconfirmed L 98-59 f. Its discovery was announced on 27 June 2019 on the NASA website. It was the smallest planet discovered by TESS until the discovery of LHS 1678b, and was the lowest-mass planet whose mass has been measured using radial velocities until Proxima Centauri d was found in 2022.

References

  1. 1 2 3 4 5 6 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.
  2. 1 2 3 Zacharias, N.; Finch, C. T.; Girard, T. M.; Henden, A.; Bartlett, J. L.; Monet, D. G.; Zacharias, M. I. (1 February 2013). "The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". The Astronomical Journal. 145 (2): 44. arXiv: 1212.6182 . Bibcode:2013AJ....145...44Z. doi:10.1088/0004-6256/145/2/44. ISSN   0004-6256. S2CID   119299381.
  3. 1 2 3 4 Demangeon, Oliver D. S.; Zapatero Osorio, M. R.; Alibert, Y.; Barros, S. C. C.; Adibekyan, V.; Tabernero, H. M.; et al. (July 2021). "A warm terrestrial planet with half the mass of Venus transiting a nearby star" (PDF). Astronomy & Astrophysics. 653: 38. arXiv: 2108.03323 . Bibcode:2021A&A...653A..41D. doi:10.1051/0004-6361/202140728. S2CID   236957385.
  4. ↑ Cloutier, R.; Astudillo-Defru, N.; Bonfils, X.; Jenkins, J. S.; Berdiñas, Z.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J.; Jenkins, J. M. (2019-09-01). "Characterization of the L 98-59 multi-planetary system with HARPS - Mass characterization of a hot super-Earth, a sub-Neptune, and a mass upper limit on the third planet". Astronomy & Astrophysics . 629: A111. arXiv: 1905.10669 . Bibcode:2019A&A...629A.111C. doi:10.1051/0004-6361/201935957. hdl: 1721.1/125703 . ISSN   0004-6361. S2CID   166228063.
  5. 1 2 Kostov, Veselin B.; Schlieder, Joshua E.; Barclay, Thomas; Quintana, Elisa V.; Colon, Knicole D.; Brande, Jonathan; Collins, Karen A.; Feinstein, Adina D.; Hadden, Samuel; Kane, Stephen R.; Kreidberg, Laura (2019-06-27). "The L 98-59 System: Three Transiting, Terrestrial-Sized Planets Orbiting a Nearby M-dwarf". The Astronomical Journal . 158 (1): 32. arXiv: 1903.08017 . Bibcode:2019AJ....158...32K. doi: 10.3847/1538-3881/ab2459 . hdl: 1721.1/124742 . ISSN   1538-3881. S2CID   118855908.
  6. 1 2 "Comparison of the L 98-59 exoplanet system with the inner Solar System". European Southern Observatory . Retrieved 2021-08-07.
  7. 1 2 "EarthSky | An inner solar system much like ours, 35 light-years away". Earth & Sky . 2021-08-06. Retrieved 2021-08-07.
  8. ↑ "New ESO observations show rocky exoplanet has just half the mass of Venus". European Southern Observatory. 5 August 2021. eso2112. Retrieved 8 August 2021.
  9. ↑ Pidhorodetska, Daria; et al. (29 September 2021). "L 98-59: A Benchmark System of Small Planets for Future Atmospheric Characterization". The Astronomical Journal . 162 (4): 169. arXiv: 2106.00685 . Bibcode:2021AJ....162..169P. doi: 10.3847/1538-3881/ac1171 . S2CID   235293792.
  10. ↑ Damiano, Mario; Hu, Renyu; et al. (November 2022). "A Transmission Spectrum of the Sub-Earth Planet L98-59 b in 1.1-1.7 μm". The Astronomical Journal . 164 (5): 225. arXiv: 2210.10008 . Bibcode:2022AJ....164..225D. doi: 10.3847/1538-3881/ac9472 .
  11. ↑ Zhou, Li; Ma, Bo; et al. (November 2022). "Hubble WFC3 Spectroscopy of the Rocky Planet L 98-59 b: No Evidence for a Cloud-free Primordial Atmosphere". The Astronomical Journal . 164 (5): 203. arXiv: 2210.10699 . Bibcode:2022AJ....164..203Z. doi: 10.3847/1538-3881/ac8fe9 .
  12. ↑ Zhou, Li; Ma, Bo; et al. (February 2023). "Hubble WFC3 Spectroscopy of the Terrestrial Planets L 98-59 c and d: No Evidence for a Clear Hydrogen Dominated Primary Atmosphere". Research in Astronomy and Astrophysics . 23 (2): 025011. arXiv: 2212.09526 . Bibcode:2023RAA....23b5011Z. doi:10.1088/1674-4527/acaceb. S2CID   254854167.
  13. ↑ Barclay, Thomas; et al. (2023), The transmission spectrum of the potentially rocky planet L 98-59 c, arXiv: 2301.10866
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.