本周初,17P/Holmes彗星让地球上的彗星观测者们着实惊叹了一把。10月24日,在数小时内它的亮度增加了50万倍之多。这次爆发让它从一颗大约7年才绕太阳运行一圈的模糊昏暗彗星成为一颗能与英仙座内较亮恒星媲美,并能用肉眼看到的彗星。这张影像就是在当天拍摄的,地点在伊朗首都德黑兰,影像中突出了城市上空新出现的肉眼可见的彗星。Holmes彗星爆发的原因可能是新形成的彗冰突然爆发,甚至可能是彗核发生分裂。在今后的几天里,这颗彗星还将保持明亮的状态。(文:节选自“每日天文一图”)
17P/Holmes
Orbital Elements
The following orbital elements are taken from MPC 51822:
17P/Holmes
Epoch 2007 May 20.0 TT = JDT 2454240.5
T 2007 May 4.4995 TT MPC
q 2.053169 (2000.0) P Q
n 0.1432508 Peri. 24.2585 +0.9756506 +0.1267918
a 3.617468 Node 326.8675 -0.2124462 +0.7491399
e 0.432429 Incl. 19.1132 +0.0545208 +0.6501640
P 6.88
From 139 observations 1964-2001, mean residual 0".7. Nongravitational
parameters A1 = +0.19, A2 = +0.0287.
Elements are also available for the current standard epoch:
17P/Holmes
Epoch 2007 Oct. 27.0 TT = JDT 2454400.5
T 2007 May 4.5277 TT MPC
q 2.053218 (2000.0) P Q
n 0.1431946 Peri. 24.2712 +0.9756707 +0.1266254
a 3.618414 Node 326.8646 -0.2123230 +0.7491869
e 0.432564 Incl. 19.1126 +0.0546417 +0.6501423
P 6.88
星历表
Date TT R. A. (2000) Decl. Delta r Elong. Phase m1 m2
WARNING!
This comet gets close to the sun during the period covered
in the ephemeris below. Observers are warned to be wary
of observing comets near the sun. NEVER point any kind of
optical instrument at the sun--instant blindness will be
the probable result.
2007 09 27 04 01.48 +46 22.6 1.756 2.337 113.0 23.3 16.8 20.2
2007 10 02 04 02.37 +47 14.2 1.728 2.355 116.8 22.3 16.8 20.1
2007 10 07 04 02.22 +48 01.8 1.702 2.373 120.7 21.2 16.8 20.1
2007 10 12 04 01.00 +48 44.8 1.678 2.391 124.6 20.1 16.8 20.0
2007 10 17 03 58.71 +49 22.2 1.659 2.410 128.6 18.9 16.8 20.0
2007 10 22 03 55.40 +49 53.1 1.642 2.428 132.5 17.6 16.9 19.9
2007 10 27 03 51.17 +50 16.6 1.630 2.447 136.3 16.3 16.9 19.9
2007 11 01 03 46.14 +50 31.9 1.623 2.467 139.9 15.0 16.9 19.8
2007 11 06 03 40.50 +50 38.3 1.620 2.486 143.2 13.8 17.0 19.8
2007 11 11 03 34.47 +50 35.4 1.623 2.506 146.0 12.8 17.0 19.8
2007 11 16 03 28.31 +50 23.1 1.631 2.526 148.2 11.9 17.1 19.8
2007 11 21 03 22.27 +50 02.1 1.646 2.546 149.4 11.4 17.2 19.8
2007 11 26 03 16.60 +49 33.0 1.666 2.567 149.7 11.2 17.2 19.8
2007 12 01 03 11.49 +48 57.0 1.692 2.587 149.0 11.3 17.3 19.9
2007 12 06 03 07.09 +48 15.5 1.724 2.608 147.3 11.8 17.4 20.0
2007 12 11 03 03.53 +47 29.9 1.761 2.628 144.8 12.5 17.5 20.1
2007 12 16 03 00.88 +46 41.7 1.805 2.649 141.8 13.3 17.6 20.2
2007 12 21 02 59.17 +45 52.3 1.854 2.670 138.4 14.2 17.7 20.3
2007 12 26 02 58.38 +45 02.9 1.908 2.692 134.6 15.1 17.9 20.4
2007 12 31 02 58.47 +44 14.5 1.967 2.713 130.7 15.9 18.0 20.5
2008 01 05 02 59.41 +43 28.0 2.030 2.734 126.7 16.8 18.1 20.6
2008 01 10 03 01.13 +42 43.8 2.097 2.755 122.7 17.5 18.2 20.7
2008 01 15 03 03.59 +42 02.5 2.168 2.777 118.6 18.1 18.3 20.8
2008 01 20 03 06.71 +41 24.3 2.242 2.798 114.6 18.6 18.5 20.9
2008 01 25 03 10.44 +40 49.2 2.319 2.820 110.6 19.1 18.6 21.0
2008 01 30 03 14.71 +40 17.3 2.399 2.842 106.6 19.4 18.7 21.1
2008 02 04 03 19.47 +39 48.4 2.480 2.863 102.7 19.6 18.8 21.2