Planet pengembara
Planet pengembara (dalam bahasa Inggris disebut rogue planet) adalah benda langit sebesar planet yang mengorbit pusat galaksi secara langsung. Objek semacam ini terlempar dari sistem keplanetan yang menjadi tempat terbentuknya planet ini, walaupun terdapat kemungkinan objek ini memang tidak pernah mengitari suatu bintang atau katai coklat.[1][2][3] Galaksi Bima Sakti sendiri diperkirakan memiliki miliaran planet pengembara.[4]
Beberapa planet pengembara mungkin terbentuk dengan cara yang sama seperti bintang, dan Persatuan Astronomi Internasional mengusulkan agar objek semacam itu disebut "katai sub-coklat".[5] Contohnya adalah Cha 110913-773444, yang mungkin terlempar dari sistem keplanetannya dan menjadi planet pengembara, atau terbentuk sendirian dan menjadi katai sub-cokelat.[6]
Pada Desember 2013, diumumkan kemungkinan penemuan sebuah bulan luar surya yang mengelilingi sebuah planet pengembara.[7]
Observasi
Ahli astrofisika Takahiro Sumi dari Universitas Osaka di Jepang dan rekan-rekannya, yang membentuk Observasi Microlensing dalam Astrofisika dan kolaborasi Eksperimen Gravitasi Optik Lensa, menerbitkan studi mereka tentang microlensing pada tahun 2011. Mereka mengamati 50 juta bintang di Bima Sakti menggunakan teleskop MOA-II 1,8 meter di Observatorium Mount John Selandia Baru dan teleskop Universitas Warsawa 1,3 meter di Observatorium Las Campanas Chile. Mereka menemukan 474 insiden microlensing, sepuluh di antaranya cukup singkat untuk menjadi planet seukuran Jupiter tanpa bintang terkait di sekitarnya. Para peneliti memperkirakan dari pengamatan mereka bahwa ada hampir dua planet pengembara bermassa Jupiter untuk setiap bintang di Bima Sakti. [8] [9] [10] Perkiraan lain menunjukkan jumlah yang jauh lebih besar, hingga 100.000 kali lebih banyak planet pengembara daripada bintang di Bima Sakti. [11] Sebuah studi tahun 2017 oleh Przemek Mróz dari Universitas Warsawa Observatory dan rekannya, dengan statistik enam kali lebih besar dari studi 2011, menunjukkan batas atas planet bermassa bebas Jupiter atau planet orbit lebar 0,25 planet per bintang urutan utama di Bima Sakti Cara. [12]
Kandidat planet pengembara terdekat termasuk WISE 0855−0714 pada jarak 7,27±0,13 tahun cahaya. [13]
Retensi panas di ruang antar bintang
Planet luar surya menghasilkan sedikit panas dan tidak dipanaskan oleh sebuah bintang.[14] Pada tahun 1998, David J. Stevenson menduga bahwa beberapa objek seukuran planet di ruang antar bintang mungkin memiliki atmosfer tebal yang membuat permukaannya tidak beku.[15]
Planet-planet Pengembara yang Dikenal
| Eksoplanet | Massa (MJ) | Usia (Miliar Tahun) | Jarak (tahun cahaya) | Catatan | Penemuan |
|---|---|---|---|---|---|
| OTS 44 | ~11.5 | 0.5–3 | 554 | Katai coklat bermassa rendah | 1998 |
| S Ori 52 | 2–8 | 1–5 | 1,150 | Usia dipertanyakan | 2000[16] |
| Cha 110913-773444 | 5–15 | ~2 | 529 | Kandidat | 2004[17] |
| SIMP J013656.5+093347 | 11-13 | ~200 | 20-22 | Kandidat | 2006[18][19] |
| UGPS J072227.51−054031.2 | 5–40 | 13 | Massa Tidak Pasti | 2010 | |
| [MPK2010b] 4450 | 2–3 | 325 | Kandidat | 2010[20] | |
| CFBDSIR 2149−0403 | 4–7 | 110–130 | 117–143 | Kandidat | 2012[21] |
| MOA-2011-BLG-262 | ~4 | Kemungkinan katai merah | 2013 | ||
| PSO J318.5-22 | 5.5–8 | 21–27 | 80 | Dikonfirmasi | 2013[22] |
| 2MASS J2208+2921 | 11–13 | 21–27 | 115 | Kandidat | 2014[23] |
| WISE J1741-4642 | 4–21 | 23–130 | Kandidat | 2014[24] | |
| WISE 0855−0714 | 3–10 | 7.1 | Kemungkinan katai coklat | 2014[25] | |
| 2MASS J12074836–3900043 | 11–13 | 7–13 | 200 | Kandidat | 2014[26] |
| SIMP J2154–1055 | 9–11 | 30–50 | 63 | Usia dipertanyakan | 2014[27] |
| SDSS J111010.01+011613.1 | 10–12 | 110–130 | 63 | Konfirmasi | 2015[28] |
| 2MASS J1119–1137 | 4–8 | 7–13 | 94 | Kandidat | 2016[29] |
| WISEA 1147 | 5–13 | 7–13 | 94 | Kandidat | 2016[30] |
| OGLE-2012-BLG-1323 | 0.007245–0.07245 | Kandidat | 2017[31][32][33] | ||
| OGLE-2017-BLG-0560 | 1.9–20 | Kandidat | 2017[34][35][36] |
Referensi
- ^ Shostak, Seth (24 February 2005). Orphan Planets: It's a Hard Knock Life. Space.com, 24 February 2005. Retrieved on 5 February 2009 from http://www.space.com/searchforlife/seti_orphan_planets_050224.html.
- ^ Lloyd, Robin (18 April 2001). Free-Floating Planets – British Team Restakes Dubious Claim. Space.com, 18 April 2001. Retrieved on 5 February 2009 from http://www.space.com/scienceastronomy/astronomy/free_floaters_010403-1.html. Error in webarchive template: Check
|url=value. Empty. - ^ Author unknown (18 April 2001). Orphan 'planet' findings challenged by new model. NASA Astrobiology, 18 April 2001. Retrieved on 5 February 2009 from "Archived copy". Diarsipkan dari versi asli tanggal 22 March 2009. Diakses tanggal 9 February 2009.
- ^ Neil deGrasse Tyson in Cosmos: A Spacetime Odyssey as referred to by National Geographic
- ^ Working Group on Extrasolar Planets – Definition of a "Planet" Position Statement on the Definition of a "Planet" (IAU) Error in webarchive template: Check
|url=value. Empty. - ^ Rogue planet find makes astronomers ponder theory
- ^ Bennett, D.P.; Batista, V.; et al. (13 December 2013). "A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge". The Astrophysical Journal. 785 (2): 155. arXiv:1312.3951
. Bibcode:2014ApJ...785..155B. doi:10.1088/0004-637X/785/2/155.
- ^ Homeless' Planets May Be Common in Our Galaxy Error in webarchive template: Check
|url=value. Empty. by Jon Cartwright, Science Now, 18 May 2011, Accessed 20 May 2011 - ^ Planets that have no stars: New class of planets discovered, Physorg.com, 18 May 2011. Accessed May 2011.
- ^ T. Sumi; et al. (2011). "Unbound or Distant Planetary Mass Population Detected by Gravitational Microlensing". Nature. 473 (7347): 349–352. arXiv:1105.3544v1 . Bibcode:2011Natur.473..349S. doi:10.1038/nature10092. PMID 21593867.
- ^ "Researchers say galaxy may swarm with 'nomad planets'". Stanford University. 2012-02-23. Diakses tanggal 29 February 2012.
- ^ P. Mroz; et al. (2017). "No large population of unbound or wide-orbit Jupiter-mass planets". Nature. 548 (7666): 183–186. arXiv:1707.07634 . Bibcode:2017Natur.548..183M. doi:10.1038/nature23276. PMID 28738410.
- ^ Luhman, Kevin L.; Esplin, Taran L. (September 2016). "The Spectral Energy Distribution of the Coldest Known Brown Dwarf". The Astronomical Journal. 152 (2). 78. arXiv:1605.06655 . Bibcode:2016AJ....152...78L. doi:10.3847/0004-6256/152/3/78.
- ^ Sean Raymond (9 April 2005). "Life in the dark" (dalam bahasa English). Aeon. Diakses tanggal 9 April 2016.
- ^ Stevenson, David J.; Stevens, C. F. (1999). "Life-sustaining planets in interstellar space?". Nature. 400 (6739): 32. Bibcode:1999Natur.400...32S. doi:10.1038/21811. PMID 10403246.
- ^ Zapatero Osorio, M. R. (6 October 2000). "Discovery of Young, Isolated Planetary Mass Objects in the σ Orionis Star Cluster". Science. 290 (5489): 103. Bibcode:2000Sci...290..103Z. doi:10.1126/science.290.5489.103.
- ^ Luhman, Kevin L. (10 December 2005). "Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk". Astrophysical Journal Letters. 635 (1): L93–L96. arXiv:astro-ph/0511807 . Bibcode:2005ApJ...635L..93L. doi:10.1086/498868.
- ^ Artigau, Étienne; Doyon, René; Lafrenière, David; Nadeau, Daniel; Robert, Jasmin; Albert, Loïc (n.d.). "Discovery of the Brightest T Dwarf in the Northern Hemisphere". The Astrophysical Journal Letters. 651 (1): L57. arXiv:astro-ph/0609419 . doi:10.1086/509146. ISSN 1538-4357.
- ^ Gagné, Jonathan; Faherty, Jacqueline K.; Burgasser, Adam J.; Artigau, Étienne; Bouchard, Sandie; Albert, Loïc; Lafrenière, David; Doyon, René; Bardalez-Gagliuffi, Daniella C. (15 May 2017). "SIMP J013656.5+093347 is Likely a Planetary-Mass Object in the Carina-Near Moving Group". The Astrophysical Journal. 841 (1): L1. arXiv:1705.01625 . doi:10.3847/2041-8213/aa70e2. ISSN 2041-8213.
- ^ Marsh, Kenneth A. (1 February 2010). "A Young Planetary-Mass Object in the ρ Oph Cloud Core". Astrophysical Journal Letters. 709 (2): L158–L162. arXiv:0912.3774 . Bibcode:2010ApJ...709L.158M. doi:10.1088/2041-8205/709/2/L158.
- ^ Delorme, Philippe (25 September 2012). "CFBDSIR2149-0403: a 4-7 Jupiter-mass free-floating planet in the young moving group AB Doradus?". Astronomy & Astrophysics. 548A: 26. arXiv:1210.0305 . Bibcode:2012A&A...548A..26D. doi:10.1051/0004-6361/201219984.
- ^ Liu, Michael C. (10 November 2013). "The Extremely Red, Young L Dwarf PSO J318.5338-22.8603: A Free-floating Planetary-mass Analog to Directly Imaged Young Gas-giant Planets". Astrophysical Journal Letters. 777 (1): L20. arXiv:1310.0457 . Bibcode:2013ApJ...777L..20L. doi:10.1088/2041-8205/777/2/L20.
- ^ Gagné, Jonathan (10 March 2014). "BANYAN. II. Very Low Mass and Substellar Candidate Members to Nearby, Young Kinematic Groups with Previously Known Signs of Youth". Astrophysical Journal. 783 (2): 121. arXiv:1312.5864 . Bibcode:2014ApJ...783..121G. doi:10.1088/0004-637X/783/2/121.
- ^ Schneider, Adam C. (9 January 2014). "Discovery of the Young L Dwarf WISE J174102.78-464225.5". Astronomical Journal. 147 (2): 34. arXiv:1311.5941 . Bibcode:2014AJ....147...34S. doi:10.1088/0004-6256/147/2/34.
- ^ Luhman, Kevin L. (10 May 2014). "Discovery of a ~250 K Brown Dwarf at 2 pc from the Sun". Astrophysical Journal Letters. 786 (2): L18. arXiv:1404.6501 . Bibcode:2014ApJ...786L..18L. doi:10.1088/2041-8205/786/2/L18.
- ^ Gagné, Jonathan (10 April 2014). "The Coolest Isolated Brown Dwarf Candidate Member of TWA". Astrophysical Journal Letters. 785 (1): L14. arXiv:1403.3120 . Bibcode:2014ApJ...785L..14G. doi:10.1088/2041-8205/785/1/L14.
- ^ Gagné, Jonathan (1 September 2014). "SIMP J2154-1055: A New Low-gravity L4β Brown Dwarf Candidate Member of the Argus Association". Astrophysical Journal Letters. 792 (1): L17. arXiv:1407.5344 . Bibcode:2014ApJ...792L..17G. doi:10.1088/2041-8205/792/1/L17.
- ^ Gagné, Jonathan (20 July 2015). "SDSS J111010.01+011613.1: A New Planetary-mass T Dwarf Member of the AB Doradus Moving Group". Astrophysical Journal Letters. 808 (1): L20. arXiv:1506.04195 . Bibcode:2015ApJ...808L..20G. doi:10.1088/2041-8205/808/1/L20.
- ^ Kellogg, Kendra (11 April 2016). "The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog". Astrophysical Journal Letters. 821 (1): L15. arXiv:1603.08529 . Bibcode:2016ApJ...821L..15K. doi:10.3847/2041-8205/821/1/L15.
- ^ Schneider, Adam C. (21 April 2016). "WISEA J114724.10-204021.3: A Free-floating Planetary Mass Member of the TW Hya Association". Astrophysical Journal Letters. 822 (1): L1. arXiv:1603.07985 . Bibcode:2016ApJ...822L...1S. doi:10.3847/2041-8205/822/1/L1.
- ^ Becky Ferreira (9 Nov 2018). "Rare Sighting of Two Rogue Planets That Do Not Orbit Stars" (dalam bahasa English). Motherboard. Diakses tanggal 10 February 2019.
- ^ Jake Parks (16 November 2018). "These Two New 'Rogue Planets' Wander the Cosmos Without Stars" (dalam bahasa English). Discover Magazine. Diakses tanggal 10 February 2019.
- ^ Jake Parks (15 November 2018). "Two free-range planets found roaming the Milky Way in solitude" (dalam bahasa English). Astronomy Magazine. Diakses tanggal 10 February 2019.
- ^ Becky Ferreira (9 Nov 2018). "Rare Sighting of Two Rogue Planets That Do Not Orbit Stars" (dalam bahasa English). Motherboard. Diakses tanggal 10 February 2019.
- ^ Jake Parks (16 November 2018). "These Two New 'Rogue Planets' Wander the Cosmos Without Stars" (dalam bahasa English). Discover Magazine. Diakses tanggal 10 February 2019.
- ^ Jake Parks (15 November 2018). "Two free-range planets found roaming the Milky Way in solitude" (dalam bahasa English). Astronomy Magazine. Diakses tanggal 10 February 2019.
