鯨魚座DK

鯨魚座DK，也稱為HD 12039，距離地球135 ly（41 pc），是位於星座鯨魚座的一顆變星。因為表面磁活動與恆星自轉耦合引起的光度變化，它被歸類為天龍座BY型變星。它與太陽相似，恆星分類為G4V，表明這是一顆主序星恆星，通過氫的核融合在其核心產生能量。表面有效溫度 5,585K，使恆星呈現黃色。它的質量與太陽差不多，但只發出太陽89%的光度。這是一顆年輕的恆星，年齡估計在750萬至800萬年之間 to 30 million years.。 2006年，利用史匹哲太空望遠鏡的紅外觀測，在這顆恆星周圍的軌道上發現了一個碎片場。這些碎片被認為是一個小行星帶，碎片的量測溫度為110 K，這使其位於距離恒星4到6AU之間的軌道上，或者與木星繞太陽運行的距離大致相同。這個岩屑盤可能是由一個直徑100公里的星子在碰撞中破裂形成的。該恆星系統在70μm處沒有顯示出任何過量發射，這表明它沒有一個冷的外部塵埃盤。 這顆恆星被檢查是否存在一顆質量在2-10木星質量範圍內、軌道距離為3-15.5AU的太陽系外行星。然而，在2007年，很可能發現了一顆近距離的恆星伴星。此對象與主對象相隔0.15弧秒，因此不太可能是背景天體。 這顆恆星已被提議為杜鵑-時鐘座星協（英语：Tucana-Horologium association）（Tuc-Hor）的成員，這是一個在太空中有共同運動的年輕恆星流。這個星協已有3,000萬年的年齡。 這顆恆星的空間速度分量是[U, V, W] = [−0.6, −16.3, 5.0] km/s。它圍繞銀河系運行，軌道離心率為0.06，與星系核心的距離在7.11−8.01 kpc之間變化。其軌道的傾斜使其高出銀河系平面90秒差距 MAST: Barbara A. Mikulski Archive for Space Telescopes. Space Telescope Science Institute. [8 December 2021].  Vallenari, A.; et al. Gaia Data Release 3. Summary of the content and survey properties. Astronomy & Astrophysics. 2022. arXiv:2208.00211 . doi:10.1051/0004-6361/202243940 .  已忽略未知参数|collaboration= (帮助) Gaia DR3 record for this source at VizieR. Torres, G. R.; et al. Search for associations containing young stars (SACY). I. Sample and searching method. Astronomy and Astrophysics. December 2006, 460 (3): 695–708. Bibcode:2006A&A...460..695T. S2CID 16080025. arXiv:astro-ph/0609258 . doi:10.1051/0004-6361:20065602.  Nordström, B.; et al. The Geneva-Copenhagen Survey of the Solar Neighbourhood. Publications of the Astronomical Society of Australia. 2004, 21 (2): 129–133. Bibcode:2004PASA...21..129N. S2CID 123457673. arXiv:0811.3982 . doi:10.1071/AS04013.  Holmberg, J.; Nordstrom, B.; Andersen, J. The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics. Astronomy and Astrophysics. July 2009, 501 (3): 941–947. Bibcode:2009A&A...501..941H. S2CID 118577511. arXiv:0811.3982 . doi:10.1051/0004-6361/200811191.  Detailed Description of V/130. VizieR catalogue service. Centre de Données astronomiques de Strasbourg. [2009-09-07].  Weidenschilling, S. J. Collisional and Luminosity Evolution of a Debris Disk: The Case of HD 12039. The Astrophysical Journal. October 2010, 722 (2): 1716–1726. Bibcode:2010ApJ...722.1716W. doi:10.1088/0004-637X/722/2/1716 .  Roccatagliata, V.; et al. Long-wavelength observations of debris discs around sun-like stars. Astronomy and Astrophysics. April 2009, 497 (2): 409–421. Bibcode:2009A&A...497..409R. S2CID 18417944. arXiv:0902.0338 . doi:10.1051/0004-6361/200811018.  Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M., Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo (PDF), Astronomy and Astrophysics, January 2009, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377  [永久失效連結] Kazarovets, A. V.; et al. The 74th Special Name-list of Variable Stars. Information Bulletin on Variable Stars. 1999, 4659: 1 [2011-11-05]. Bibcode:1999IBVS.4659....1K. （原始内容存档于2018-11-30）.  Wichmann, R.; Schmitt, J. H. M. M.; Hubrig, S. Nearby young stars. Astronomy and Astrophysics. March 2003, 399 (3): 983–994. Bibcode:2003A&A...399..983W. doi:10.1051/0004-6361:20021867 .  Hines, Dean C.; et al. The Formation and Evolution of Planetary Systems (FEPS): Discovery of an Unusual Debris System Associated with HD 12039. The Astrophysical Journal. February 20, 2006, 638 (2): 1070–1079. Bibcode:2006ApJ...638.1070H. S2CID 14919914. arXiv:astro-ph/0510294 . doi:10.1086/498929.  Greaves, Jane; et al. The composition of debris around HD 12039: water from asteroids?. Spitzer Proposal ID #40310. May 2007: 40310. Bibcode:2007sptz.prop40310G.  Klahr, Hubert; Brandner, Wolfgang. Planet formation: theory, observations and experiments. Cambridge University Press. 2006: 28. ISBN 978-0-521-86015-4.  Biller, Beth A.; et al. An Imaging Survey for Extrasolar Planets around 45 Close, Young Stars with the Simultaneous Differential Imager at the Very Large Telescope and MMT. The Astrophysical Journal Supplement Series. November 2007, 173 (1): 143–165. Bibcode:2007ApJS..173..143B. doi:10.1086/519925 .  Zuckerman, B.; Song, Inseok. Young Stars Near the Sun. Annual Review of Astronomy & Astrophysics. 2004, 42 (1): 685–721. Bibcode:2004ARA&A..42..685Z. S2CID 34114530. doi:10.1146/annurev.astro.42.053102.134111.  Makarov, Valeri V. Unraveling the Origins of Nearby Young Stars. The Astrophysical Journal Supplement Series. March 2007, 169 (1): 105–119. Bibcode:2007ApJS..169..105M. doi:10.1086/509887 .  Spitzer Team Says Debris Disk Could Be Forming Infant Terrestrial Planets. Jet Propulsion Laboratory/Space Science Institute. December 14, 2005 [2011-01-24].