天蝎座V1309 SCO 红新星

     天蝎座V1309 SCO 是我个人所有天文发现中最有意义的一次发现,天蝎座V1309发现者有日本的天文爱好者 K. Nishiyama ,F. Kabashima, Y. Sakuri和我跟高兴老师,虽然不是第一发现者,但还是让我感到无比荣幸天蝎座V1309 SCO是天蝎座发现的一颗新星,后来科学家发现它是由双星合并形成的红新星。天蝎座V1309V1309 SCO是仅有的几个确认的红新星,第一颗被确认的发光红新星是2006年在M851星系的M85OT2006-1,而著名的麒麟座V838很可能也是一个红新星。

可能的“红新星”麒麟座V838在爆发后演化图景,由哈勃望远镜观测

什么是红新星?

      直到2006年,人类才真正确认了一次双星合并事件。利克天文台(Lick Observatory)超新星搜寻项目在距地球6000万光年的M85星系中发现了M85 OT2006-1的爆发,加州大学伯克利分校和加州理工的天文学家随后进行了详尽分析,发现这次爆发来源于两个低质量双星的合并,不同于之前其它所知道的新星爆发。但因此次爆发前的监测信息不足,所以,我们对于合并之前的双星系统十分缺乏了解。在这一年,天文学家们根据观测所得,为双星合并所形成的新星赋予了一个名字:“亮红新星”(luminous red novae)。

      真正帮助天文学家解开“红新星”之谜的钥匙,藏在天蝎座V1309之中。这个系统最早是被中国和日本的天文爱好者发现的,他们随后将相关信息提交给了国际天文联合会的天体变源监测组织。然而,天蝎座V1309的详尽数据来自一个名为Optical Gravitational Lensing Experiment(简写为OGLE;光学引力透镜实验)的巡天项目。该项目由波兰华沙大学的天文学家于2001年正式启动,初衷是对大面积天区进行监测,希望寻找亮度发生变化的天体源,发现引力透镜现象,从而检验一些最初被认为可能构成暗物质的天体,比如黑洞。天蝎座V1309所在的位置刚好处于OGLE的监测天区之内,所以天文学家得到了其在爆发前直至爆发后的、长时间范围的大量观测数据。之后的数据分析不仅仅确认了这是一个“红新星”系统(双星合并后的系统),还为我们提供了更为重要的信息,即这个双星系统在合并之前是如何随时间演化的。

       正是在天蝎座V1309系统合并前的观测数据以及建模基础之上,莫尔纳教授等人对KIC 9832227的系统演化做出了判断,预测这两颗恒星“亲密接触”并最终合并,将发生在2021年9月-2022年9月间。

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IAU8972号公报      

Circular No. 8972
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)


V1309 SCORPII = NOVA SCORPII 2008
S. Nakano, Sumoto, Japan, reports the discovery by K.
Nishiyama (Kurume, Fukuoka-ken) and F. Kabashima (Miyaki-cho, Saga-
ken) of a bright star (mag 9.5) on unfiltered CCD images obtained
on Sept. 2.4594 UT with a 0.40-m f/9.8 reflector, the presumed nova
being located at R.A. = 17h57m32s.93 +/- 0s.01, Decl. =
-30o43'10".1 +/- 0".1 (equinox 2000.0). Nothing is visible at this
position on their unfiltered CCD frames taken on Aug. 20.476
(limiting mag 12.8) and 21.470 (limiting mag 12.1) using a patrol
camera (+ 105-mm-f.l. f/5.6 lens). They note nearby USNO-B1.0-
catalogue stars at position end figures 33s.221, 10".56 (red mag
12.7) and 33s.015, 10".39 (red mag 14.8). Additional independent
discoveries also were reported from survey images obtained with
digital cameras and telephoto lenses by Y. Sakurai (Mito, Ibaraki-
ken, Japan; via Nakano; nova at mag 9.7 on Sept. 3.4) and by Guoyou
Sun (Qufu, Shandong, China) and Xing Gao (Urumqi, Xinjiang, China)
in the course of the Xingming Observatory Nova Survey (mag
approximately 10.5 on Sept. 2.6). Following posting on the CBAT
unconfirmed-objects webpage, several other observers sent
observations of V1309 Sco that were included with additional
discovery details on CBET 1496. Additional selected magnitudes
(mostly from unfiltered CCD images) for the nova: 1958 Apr. 18,
[19.0 (red Palomar Sky Survey, via C. Jacques and E. Pimentel, Belo
Horizonte, Brazil); 2008 July 30, [12 (Sakurai); Aug. 14, 20, 21,
and 30, [13.5: (Sun and Gao); 30.783, [14.5 (D. Chekhovich, S.
Korotkiy, and T. Kryachko, Karachay-Cherkessia, Russia); 31, [13.5:
(Sun and Gao); Sept. 2.735, 10.5 (Chekhovich et al.); 3.512, 9.0
(Nishiyama and Kabashima); 4.489, 8.3 (Nishiyama and Kabashima);
5.483, 7.1 (Nishiyama and Kabashima). N. N. Samus, Institute of
Astronomy, Moscow, informs us that this nova has been assigned the
designation V1309 Sco.
H. Naito, Nishi-Harima Astronomical Observatory, reports that
low-resolution spectra of V1309 Sco were taken on Sept. 3.49 and
4.47 UT by M. Fujii (Ibara, Okayama, Japan, 0.28-m reflector; range
400-800 nm, resolution R about 500) and on Sept. 5.47 by Naito with
the 2.0-m NAYUTA telescope (+ MALLS; range 410-670 nm, R about 1200).
The spectra show a smooth continuum with some absorption lines and
strong Balmer emission lines, which indicate that this object is
indeed a classical nova. The expansion velocities derived from the
FWHM of H_alpha are somewhat slow (670 km/s on Sept. 3.49, 670 km/s
on Sept. 4.47, and 470 km/s on Sept. 5.47). The spectrum also
shows an interstellar Na D absorption line (EW = 0.6 nm). The
ratios of H_alpha to H_beta are 10 on Sept. 4.47 and 6.7 on Sept.
5.47.

(C) Copyright 2008 CBAT
2008 September 6 (8972) Daniel W. E. Green

 

 

相关文章 (论文):

1,五年后,我们将见证双星合并  http://www.kepuchina.cn/qykj/hkht/201701/t20170124_65726.shtml

2,WIKI V1309 Scorpii  https://en.wikipedia.org/wiki/V1309_Scorpii

3,Post-outburst spectra of a stellar-merger remnant of V1309 Scorpii: from a twin of V838 Monocerotis to a clone of V4332 Sagittarii. https://arxiv.org/abs/1504.03421v2