Jovian exoplanet orbiting HR 8799
HR 8799 c is anextrasolar planet located approximately 129light-years away in theconstellation ofPegasus , orbiting the 6thmagnitude Lambda Boötis star HR 8799 . This planet has a mass between 5 and 10Jupiter masses and a radius from 20 to 30% larger thanJupiter 's. It orbits at 38AU from HR 8799 with an unknown eccentricity and a period of 190 years; it is the 2nd planet discovered in the HR 8799 system. Along with two other planets orbiting HR 8799, this planet was discovered on November 13, 2008, by Marois et al., using theKeck and theGemini observatories inHawaii . These planets were discovered using thedirect imaging technique.[ 1] [ 5] [ 6] [ 7] [ 8] 2M1207b ,DH Tau b ,GQ Lup b ,AB Pic b ,CHXR 73 b ,HD 203030 b ,CT Cha b and1RXS J1609b ), confirming the feasibility of direct spectrographic studies of exoplanets.[ 2] [ 9]
The spectrum of the planet HR 8799 c. The spectrum of the star and the planet was obtained with the NACO adaptive optics instrument onESO ’sVery Large Telescope . Near infrared spectroscopy from 995 to 1769 nanometers made with the Palomar Observatory show evidence ofammonia , perhaps someacetylene but neithercarbon dioxide nor substantialmethane .[ 10] [ 11] [ 12]
Later, in November 2018, researchers confirmed the existence ofwater and the absence of methane in the atmosphere of HR 8799c, using high-resolution spectroscopy and near-infrared adaptive optics (NIRSPAO ) at the Keck Observatory.[ 13] [ 14]
The detection of water andcarbon monoxide in the planetary atmosphere was announced in 2021.[ 15]
^ Value given assuming the planet's orbit is circular and is being observed face-on. ^a b c Marois, Christian; et al. (November 2008). "Direct Imaging of Multiple Planets Orbiting the Star HR 8799".Science 322 (5906):1348– 1352.arXiv :0811.2606 Bibcode :2008Sci...322.1348M .doi :10.1126/science.1166585 .PMID 19008415 .S2CID 206516630 . ^a b Jason, M.; C. Bergfors; M. Goto; W. Brandner; D. Lafrenière (2010)."Spatially resolved spectroscopy of the exoplanet HR 8799 c" (PDF) .The Astrophysical Journal .710 (1):L35 – L38 .arXiv :1001.2017 Bibcode :2010ApJ...710L..35J .doi :10.1088/2041-8205/710/1/l35 .S2CID 9159181 . Retrieved2010-01-13 . ^ Marois; Zuckerman; Konopacky; Macintosh; Barman (2010). "Images of a fourth planet orbiting HR 8799".Nature .468 (7327):1080– 1083.arXiv :1011.4918 Bibcode :2010Natur.468.1080M .doi :10.1038/nature09684 .PMID 21150902 .S2CID 4425891 . ^ "Exoplanet HR 8799 c" . Retrieved29 July 2024 .^ "Astronomers capture first images of newly-discovered solar system" (Press release). W. M. Keck Observatory. 2008-11-13. Archived fromthe original on 2013-11-26. Retrieved2008-12-02 .^ "Gemini Releases Historic Discovery Image of Planetary First Family" (Press release). Gemini Observatory. 2008-11-13. Retrieved2008-12-02 .^ Achenbach, Joel (2008-11-13)."Scientists Publish First Direct Images of Extrasolar Planets" .The Washington Post . Retrieved2008-12-02 . ^ Fabrycky; et al. (2010). "Stability of the directly imaged multiplanet system HR 8799: resonance and masses".Astrophys. J .710 (2):1408– 1421.arXiv :0812.0011 Bibcode :2010ApJ...710.1408F .doi :10.1088/0004-637X/710/2/1408 .S2CID 11760422 . ^ Janson, M. (13 January 2010)."VLT Captures First Direct Spectrum of an Exoplanet" .ESO . La Silla Observatory: 2.Bibcode :2010eso..pres....2. Retrieved2010-01-13 . ^ B. R. Oppenheimer (2013). "Reconnaissance of the HR 8799 Exosolar System I: Near IR Spectroscopy".The Astrophysical Journal .768 (1).Cornell University : 24.arXiv :1303.2627 Bibcode :2013ApJ...768...24O .doi :10.1088/0004-637X/768/1/24 .S2CID 7173368 . ^ "Alien planet's atmosphere contains water and carbon monoxide" . Archived fromthe original on 2019-03-30. Retrieved2013-03-14 .^ "Giant Alien Planet in Supersized Solar System May Solve Mystery" .Space.com Archived from the original on 2023-06-07.^ W. M. Keck Observatory (20 November 2018)."Exoplanet stepping stones - Researchers are perfecting technology to one day look for signs of alien life" .EurekAlert! . Retrieved21 November 2018 .^ Wang, Ji; et al. (20 November 2018)."Detecting Water in the Atmosphere of HR 8799 c with L-band High-dispersion Spectroscopy Aided by Adaptive Optics" .The Astronomical Journal 156 (6): 272.arXiv :1809.09080 Bibcode :2018AJ....156..272W .doi :10.3847/1538-3881/aae47b S2CID 119372301 . ^ Wang, Jason J.; et al. (2021), "Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy",The Astronomical Journal ,162 (4): 148,arXiv :2107.06949 Bibcode :2021AJ....162..148W ,doi :10.3847/1538-3881/ac1349 S2CID 235898867 HR 8799 c at Wikimedia Commons
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