LTT 3780
LTT 3780, also known as TOI-732 or LP 729-54, is the primary of the binary stellar system LDS 3977 in the constellation Hydra.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 10h 18m 35.137s |
| Declination | −11° 43′ 0.242″ |
| Apparent magnitude (V) | 13.14 |
| Characteristics | |
| Spectral type | M4V |
| Apparent magnitude (b) | 14.678 |
| Apparent magnitude (g) | 11.8465 |
| Apparent magnitude (j) | 9.007 |
| Astrometry | |
| Proper motion (μ) | RA: -341.409 mas/yr Dec.: -247.870 mas/yr |
| Parallax (π) | 45.4644 ± 0.0827 mas[1] |
| Distance | 71.7 ± 0.1 ly (22.00 ± 0.04 pc) |
| Absolute magnitude (MV) | 11.43 |
| Details | |
| Mass | 0.401 M☉ |
| Radius | 0.374 R☉ |
| Surface gravity (log g) | 4.896 cgs |
| Temperature | 3331 K |
| Metallicity [Fe/H] | 0.28 dex |
| Rotational velocity (v sin i) | 1.3 km/s |
| Age | 5 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Characteristics
LTT 3780 is an M-type main-sequence star. It is of similar age to Sun and relatively enriched in metals.
Planetary system
In 2020, an analysis carried out by a team of astronomers led by astronomer Ryan Cloutier of the TESS project confirmed the existence of two planets on mildly eccentric orbits, the inner being a super-Earth and the outer a small gas giant about half the mass of Uranus.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.34+0.24 −0.23 M🜨 |
0.01203+0.00054 −0.00053 |
0.77±0.001 | 0.064+0.075 −0.046 |
85.9° | 1.35±0.06 R🜨 |
| c | 6.29+0.63 −0.61 M🜨 |
0.0762±0.0034 | 12.252131+0.000072 −0.000064 |
0.115+0.07 −0.065 |
89.08° | 2.42±0.1 R🜨 |
References
- 162-44 G 162-44, entry, SIMBAD. Accessed March 6, 2020.
- Cloutier, Ryan; Eastman, Jason D.; Rodriguez, Joseph E.; Astudillo-Defru, Nicola; Bonfils, Xavier; Mortier, Annelies; Watson, Christopher A.; Stalport, Manu; Pinamonti, Matteo; Lienhard, Florian; Harutyunyan, Avet; Damasso, Mario; Latham, David W.; Collins, Karen A.; Massey, Robert; Irwin, Jonathan; Winters, Jennifer G.; Charbonneau, David; Ziegler, Carl; Matthews, Elisabeth; Crossfield, Ian J. M.; Kreidberg, Laura; Quinn, Samuel N.; Ricker, George; Vanderspek, Roland; Seager, Sara; Winn, Joshua; Jenkins, Jon M.; Vezie, Michael; et al. (2020). "A pair of TESS planets spanning the radius valley around the nearby mid-M dwarf LTT 3780". The Astronomical Journal. 160 (1): 3. arXiv:2003.01136. Bibcode:2020AJ....160....3C. doi:10.3847/1538-3881/ab91c2. S2CID 211817805.
- Nowak, G.; Luque, R.; Parviainen, H.; Pallé, E.; Molaverdikhani, K.; Béjar, V. J. S.; Lillo-Box, J.; Rodríguez-López, C.; Caballero, J. A.; Zechmeister, M.; Passegger, V. M.; Cifuentes, C.; Schweitzer, A.; Narita, N.; Cale, B.; Espinoza, N.; Murgas, F.; Zapatero Osorio, M. R.; Pozuelos, F. J.; Aceituno, F. J.; Amado, P. J.; Barkaoui, K.; Barrado, D.; Bauer, F. F.; Benkhaldoun, Z.; Caldwell, D. A.; Casasayas Barris, N.; Chaturvedi, P.; Chen, G.; et al. (2020). "The CARMENES search for exoplanets around M dwarfs. Two planets on the opposite sides of the radius gap transiting the nearby M dwarf LP 729-54". Astronomy & Astrophysics. A173: 642. arXiv:2003.01140. doi:10.1051/0004-6361/202037867. S2CID 211818198.
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