Issue |
A&A
Volume 684, April 2024
|
|
---|---|---|
Article Number | A83 | |
Number of page(s) | 24 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202348813 | |
Published online | 05 April 2024 |
Wolf 327b: A new member of the pack of ultra-short-period super-Earths around M dwarfs★
1
Instituto de Astrofísica de Canarias (IAC),
calle Vía Láctea s/n,
38205
La Laguna, Tenerife, Spain
e-mail: fmurgas@iac.es
2
Departamento de Astrofísica, Universidad de La Laguna (ULL),
38206
La Laguna, Tenerife, Spain
3
Instituto de Astrofísica de Andalucía (IAA-CSIC),
Glorieta de la Astronomía s/n,
18008
Granada, Spain
4
Center for Astroparticles and High Energy Physics (CAPA), Universidad de Zaragoza,
50009
Zaragoza, Spain
5
School of Sciences, European University Cyprus,
Diogenes street, Engomi,
1516
Nicosia, Cyprus
6
Center for Astrophysics | Harvard & Smithsonian,
60 Garden Street,
Cambridge, MA
02138, USA
7
Max Planck Institute for Solar System Research,
Justus-von-Liebig-Weg 3,
37077,
Göttingen, Germany
8
Centro Astronónomico Hispano en Andalucía, Observatorio de Calar Alto, Sierra de los Filabres,
04550
Gérgal, Almería, Spain
9
Astrobiology Research Unit, Université de Liège,
19C Allée du 6 Août,
4000
Liège, Belgium
10
Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology,
77 Massachusetts Avenue,
Cambridge, MA
02139, USA
11
Sternberg Astronomical Institute Lomonosov Moscow State University
119992,
Universitetskii prospekt, 13,
Moscow, Russia
12
Centro de Astrobiología (CSIC-INTA),
ESAC campus,
28692
Villanueva de la Cañada, Madrid, Spain
13
NASA Exoplanet Science Institute, IPAC, California Institute of Technology,
Pasadena, CA
91125 USA
14
Departamento de Física de la Tierra y Astrofísica and IPARCOSUCM (Instituto de Física de Partículas y del Cosmos de la UCM), Facultad de Ciencias Físicas, Universidad Complutense de Madrid,
28040
Madrid, Spain
15
Department of Multi-Disciplinary Sciences, Graduate School of Arts and Sciences, The University of Tokyo,
3-8-1 Komaba, Meguro,
Tokyo
153-8902, Japan
16
Komaba Institute for Science, The University of Tokyo,
3-8-1 Komaba, Meguro,
Tokyo
153-8902, Japan
17
Jet Propulsion Laboratory, California Institute of Technology,
4800 Oak Grove Drive,
Pasadena, CA
91109, USA
18
Thüringer Landessternwarte Tautenburg,
Sternwarte 5,
07778
Tautenburg, Germany
19
Max-Planck-Institut für Astronomie,
Königstuhl 17,
69117
Heidelberg, Germany
20
Institut d’Estudis Espacials de Catalunya (IEEC),
c/ Gran Capità 2-4,
08034
Barcelona, Spain
21
NASA Ames Research Center,
Moffett Field, CA
94035, USA
22
Department of Astronomy and Astrophysics, University of Chicago,
Chicago, IL
60637, USA
23
Institut für Astrophysik und Geophysik, Georg-August-Universität,
Friedrich-Hund-Platz 1,
37077
Göttingen, Germany
24
Astrobiology Center,
2-21-1 Osawa, Mitaka,
Tokyo
181-8588, Japan
25
Department of Physics and Astronomy, University of Kansas,
Lawrence, KS
66045, USA
26
Landessternwarte, Zentrum für Astronomie der Universität Heidelberg,
Königstuhl 12,
69117
Heidelberg, Germany
27
Steward Observatory and Department of Astronomy, The University of Arizona,
Tucson, AZ
85721, USA
28
Hamburger Sternwarte, Universität Hamburg,
Gojenbergsweg 112,
21029
Hamburg, Germany
29
Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology,
Cambridge, MA
02139, USA
30
Department of Aeronautics and Astronautics, MIT,
77 Massachusetts Avenue,
Cambridge, MA
02139, USA
31
Department of Physics and Astronomy, Vanderbilt University,
Nashville, TN
37235, USA
32
Institute of Astronomy and Astrophysics, Academia Sinica,
PO Box 23-141,
Taipei
10617, Taiwan, ROC
33
Department of Astrophysics, National Taiwan University,
Taipei
10617, Taiwan, ROC
34
SETI Institute,
Mountain View, CA
94043 USA
35
Vereniging Voor Sterrenkunde (VVS),
Oostmeers 122 C,
8000
Brugge, Belgium
36
Centre for Mathematical Plasma-Astrophysics, Department of Mathematics,
KU Leuven, Celestijnenlaan 200B,
3001
Heverlee, Belgium
37
Public Observatory ASTROLAB IRIS, Provinciaal Domein “De Palingbeek”,
Verbrandemolenstraat 5,
8902
Zillebeke, Ieper, Belgium
38
Department of Astrophysical Sciences, Princeton University,
4 Ivy Lane,
Princeton, NJ
08544, USA
39
Società Astronomica Lunae,
Castelnuovo Magra, Italy
40
Institut de Ciències de l’Espai (ICE, CSIC),
Campus UAB, c/ de Can Magrans s/n,
08193
Bellaterra, Barcelona, Spain
Received:
1
December
2023
Accepted:
21
January
2024
Planets with orbital periods shorter than 1 day are rare and have formation histories that are not completely understood. Small (Rp < 2 R⊕) ultra-short-period (USP) planets are highly irradiated, probably have rocky compositions with high bulk densities, and are often found in multi-planet systems. Additionally, USP planets found around small stars are excellent candidates for characterization using present-day instrumentation. Of the current full sample of approximately 5500 confirmed exoplanets, only 130 are USP planets and around 40 have mass and radius measurements. Wolf 327 (TOI-5747) is an M dwarf (R* = 0.406 ± 0.015 R⊙, M* = 0.405 ± 0.019 M⊙, Teff = 3542 ± 70 K, and V = 13 mag) located at a distance d = 28.5 pc. NASA’s planet hunter satellite, TESS, detected transits in this star with a period of 0.573 day (13.7 h) and with a transit depth of 818 ppm. Ground-based follow-up photometry, high resolution imaging, and radial velocity (RV) measurements taken with the CARMENES spectrograph confirm the presence of this new USP planet. Wolf 327b is a super-Earth with a radius of Rp = 1.24 ± 0.06 R⊕ and a mass of Mp = 2.53 ± 0.46 M⊕, yielding a bulk density of 7.24 ± 1.66 g cm−3 and thus suggesting a rocky composition. Owing to its close proximity to its host star (a = 0.01 au), Wolf 327b has an equilibrium temperature of 996 ± 22 K. This planet has a mass and radius similar to K2-229b, a planet with an inferred Mercury-like internal composition. Planet interior models suggest that Wolf 327b has a large iron core, a small rocky mantle, and a negligible (if any) H/He atmosphere.
Key words: techniques: photometric / techniques: radial velocities / planets and satellites: detection / planets and satellites: terrestrial planets / stars: individual: Wolf 327 / stars: late-type
Radial velocity measurement table is available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/684/A83
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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