WASP-45

WASP-45 is a K-type main-sequence star about 701 light-years (215 parsecs) away. The star's age cannot be well constrained, but it is probably older than the Sun. Yet, WASP-45 is enriched in heavy elements compared to the Sun, having 240% of the solar abundance.^[4]

WASP-45

Observation data Epoch J2000      Equinox J2000
Constellation	Sculptor
Right ascension	00h 20m 56.99413s[1]
Declination	−35° 59′ 53.7466″[1]
Apparent magnitude (V)	11.8[2]
Characteristics
Spectral type	K2V[3]
Astrometry
Radial velocity (Rv)	4.71±0.33[1] km/s
Proper motion (μ)	RA: 52.831 mas/yr[1] Dec.: −46.940 mas/yr[1]
Parallax (π)	4.6520 ± 0.0226 mas[1]
Distance	701 ± 3 ly (215 ± 1 pc)
Details[4]
Mass	0.932+0.045 −0.046 M☉
Radius	0.891±0.013 R☉
Luminosity	0.510±0.013 L☉
Surface gravity (log g)	4.508+0.023 −0.025 cgs
Temperature	5167±29 K
Metallicity [Fe/H]	0.388+0.090 −0.10 dex
Rotational velocity (v sin i)	2.3±0.7 km/s
Age	5.4+4.7 −3.5 Gyr
Other designations
TOI-229, TIC 120610833, WASP-45, TYC 6996-583-1, GSC 06996-00583, 2MASS J00205699-3559537[2]
Database references
SIMBAD	data

The star has low ultraviolet emission, therefore it is suspected to have a low starspot activity,^[5] although chromospheric activity was reported elsewhere.^[3]

There is a companion star at a separation of 4.4 arcseconds, corresponding to 929 AU.^[6]

Planetary system

In 2011 a transiting hot Jupiter planet, WASP-45b, was detected.^[3] The planet equilibrium temperature is 1170±24 K. No Rayleigh scattering was detected in the planetary atmosphere, implying the existence of hazes or a high cloud deck.^[7]

The WASP-45 planetary system^[7][4]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	1.018+0.046 −0.045 MJ	0.04089+0.00065 −0.00069	3.1260876(35)[8]	<0.043[8]	84.686±0.098°	0.978+0.026 −0.024 RJ

References

1. 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. "WASP-45". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 10 December 2023.
3. Anderson, D. R.; Collier Cameron, A.; Gillon, M.; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Queloz, D.; Smalley, B.; Smith, A. M. S.; Triaud, A. H. M. J.; West, R. G.; Pepe, F.; Pollacco, D.; Ségransan, D.; Todd, I.; Udry, S. (2012), "WASP-44b, WASP-45b and WASP-46b: three short-period, transiting extrasolar planets", Monthly Notices of the Royal Astronomical Society, 422 (3): 1988–1998, arXiv:1105.3179, Bibcode:2012MNRAS.422.1988A, doi:10.1111/j.1365-2966.2012.20635.x, S2CID 34406657
4. Addison, Brett; Wright, Duncan J.; Wittenmyer, Robert A.; Horner, Jonathan; Mengel, Matthew W.; Johns, Daniel; Marti, Connor; Nicholson, Belinda; Okumura, Jack; Bowler, Brendan; Crossfield, Ian; Kane, Stephen R.; Kielkopf, John; Plavchan, Peter; Tinney, C. G.; Zhang, Hui; Clark, Jake T.; Clerte, Mathieu; Eastman, Jason D.; Swift, Jon; Bottom, Michael; Muirhead, Philip; McCrady, Nate; Herzig, Erich; Hogstrom, Kristina; Wilson, Maurice; Sliski, David; Johnson, Samson A.; Wright, Jason T.; et al. (2019), "MINERVA-Australis I: Design, Commissioning, & First Photometric Results", Publications of the Astronomical Society of the Pacific, 131 (1005): 115003, arXiv:1901.11231, Bibcode:2019PASP..131k5003A, doi:10.1088/1538-3873/ab03aa, S2CID 119370785
5. Shkolnik, Evgenya L. (2013), "An Ultraviolet Investigation of Activity on Exoplanet Host Stars", The Astrophysical Journal, 766 (1): 9, arXiv:1301.6192, Bibcode:2013ApJ...766....9S, doi:10.1088/0004-637X/766/1/9, S2CID 118415788
6. Mugrauer, M. (December 2019). "Search for stellar companions of exoplanet host stars by exploring the second ESA-Gaia data release". Monthly Notices of the Royal Astronomical Society. 490 (4): 5088–5102. Bibcode:2019MNRAS.490.5088M. doi:10.1093/mnras/stz2673.
7. Ciceri, S.; Mancini, L.; Southworth, J.; Lendl, M.; Tregloan-Reed, J.; Brahm, R.; Chen, G.; d'Ago, G.; Dominik, M.; Figuera Jaimes, R.; Galianni, P.; Harpsøe, K.; Hinse, T. C.; Jørgensen, U. G.; Juncher, D.; Korhonen, H.; Liebig, C.; Rabus, M.; Bonomo, A. S.; Bott, K.; Henning, Th.; Jordán, A.; Sozzetti, A.; Alsubai, K. A.; Andersen, J. M.; Bajek, D.; Bozza, V.; Bramich, D. M.; Browne, P.; et al. (2016), "Physical properties of the planetary systems WASP-45 and WASP-46 from simultaneous multi-band photometry", Monthly Notices of the Royal Astronomical Society, 456 (1): 990–1002, arXiv:1511.05171, Bibcode:2016MNRAS.456..990C, doi:10.1093/mnras/stv2698, S2CID 14670311
8. Bonomo, A. S.; Desidera, S.; et al. (June 2017). "The GAPS Programme with HARPS-N at TNG. XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets". Astronomy & Astrophysics. 602: A107. arXiv:1704.00373. Bibcode:2017A&A...602A.107B. doi:10.1051/0004-6361/201629882.