Cannabaceae

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KELT-21b
Discovery
Discovered byMarshall Johnson et al.[1]
Discovery siteKELT
Discovery date2018
Transit method
Orbital characteristics
0.05224 AU (7,815,000 km)
3.6127647[1] d
Inclination86.46[1]
StarKELT-21 A
(HD 332124)
Physical characteristics
1.586[1] RJ
Mass<3.91[1] MJ
Mean density
<1.24 g cm−3
Temperature2,051 K (1,778 °C; 3,232 °F)[1]

KELT-21b is an extrasolar planet discovered in 2017. It is a hot Jupiter with radius of about 1.586 MJ.[1]

Host star

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KELT-21b orbits KELT-21 A (HD 332124). It orbits the primary star in a triple star system, with the other two stars located 1.2 arcseconds away. These two stars, designated KELT-21 B and C, have masses of 0.13 M☉ and 0.11 M☉, respectively.[1] The primary star is heavy at 1.458±0.029M☉, extremely hot at 8210±771 K and rapidly rotating (equatorial velocity equal to 141 km/s).[2] In comparison, the Sun has a temperature of 5772 K[3] and rotates at an equatorial velocity of 1.997 km/s.[4] The planetary orbit is well aligned with the equatorial plane of the host star, with misalignment equal to −5.6+1.7
−1.9°.[5]

Transmission planetary spectroscopy was performed in 2021, based on a single transit observation in 2019. High planetary gravity and relatively low planetary temperature made detection of an atmosphere impossible that time.[6]

References

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  1. ^ a b c d e f g h Johnson, Marshall C; Rodriguez, Joseph E; Zhou, George; Gonzales, Erica J; Cargile, Phillip A; Crepp, Justin R; Penev, Kaloyan; Stassun, Keivan G; Gaudi, B. Scott; Colón, Knicole D; Stevens, Daniel J; Strassmeier, Klaus G; Ilyin, Ilya; Collins, Karen A; Kielkopf, John F; Oberst, Thomas E; Maritch, Luke; Reed, Phillip A; Gregorio, Joao; Bozza, Valerio; Novati, Sebastiano Calchi; d'Ago, Giuseppe; Scarpetta, Gaetano; Zambelli, Roberto; Latham, David W; Bieryla, Allyson; Cochran, William D; Endl, Michael; Tayar, Jamie; et al. (2018). "KELT-21b: A Hot Jupiter Transiting the Rapidly Rotating Metal-poor Late-A Primary of a Likely Hierarchical Triple System". The Astronomical Journal. 155 (2): 100. arXiv:1712.03241. Bibcode:2018AJ....155..100J. doi:10.3847/1538-3881/aaa5af. S2CID 73559090.
  2. ^ Garai, Z.; Pribulla, T.; Kovács, J.; Szabó, Gy M.; Claret, A.; Komžík, R.; Kundra, E. (2022), "Rapidly rotating stars and their transiting planets: KELT-17b, KELT-19Ab, and KELT-21b in the CHEOPS and TESS era", Monthly Notices of the Royal Astronomical Society, 513 (2): 2822–2840, arXiv:2204.09077, doi:10.1093/mnras/stac1095
  3. ^ Williams, D. R. (1 July 2013). "Sun Fact Sheet". NASA Goddard Space Flight Center. Archived from the original on 15 July 2010. Retrieved 12 August 2013.
  4. ^ "Solar System Exploration: Planets: Sun: Facts & Figures". NASA. Archived from the original on 2 January 2008.
  5. ^ Rice, Malena; Wang, Songhu; Wang, Xian-Yu; Stefánsson, Guđmundur; Isaacson, Howard; Howard, Andrew W.; Logsdon, Sarah E.; Schweiker, Heidi; Dai, Fei; Brinkman, Casey; Giacalone, Steven; Holcomb, Rae (2022), "A Tendency Toward Alignment in Single-star Warm-Jupiter Systems", The Astronomical Journal, 164 (3): 104, arXiv:2207.06511, Bibcode:2022AJ....164..104R, doi:10.3847/1538-3881/ac8153, S2CID 250526491
  6. ^ Stangret, M.; Casasayas-Barris, N.; Pallé, E.; Orell-Miquel, J.; Morello, G.; Luque, R.; Nowak, G.; Yan, F. (2022), "High-resolution transmission spectroscopy study of ultra-hot Jupiters HAT-P-57b, KELT-17b, KELT-21b, KELT-7b, MASCARA-1b, and WASP-189b", Astronomy & Astrophysics, 662: A101, arXiv:2111.13064, Bibcode:2022A&A...662A.101S, doi:10.1051/0004-6361/202141799, S2CID 244709777


source: Https://en.wikipedia.org/wiki/KELT-21b

One thought on “Cannabaceae”

  1. Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
    View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction

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