绿色彗星LONEOS接近太阳，挑战观测极限

彗星LONEOS (C/2007 F1) 已经进入地球轨道以内，亮度大增，最新拍摄的照片上，绿色的彗星拖着一条暗弱的短尾，从地面的观测来看，彗星比预报明亮1等以上，9月29日实际亮度大约在8.2等，而当时的预报约10等，彗星继续向太阳靠近，并于10月27日经过近日点，日心距离在0.4AU，估计亮度可达4等左右，近日点前北半球的观测者可在傍晚西方低空搜索这颗彗星，近日点之后，彗星迅速向南移动，但与太阳的角距很小，地面观测条件很差。

C/2007 F1 (LONEOS)
C/2007 F1 (LONEOS)
Epoch 2007 Oct. 27.0 TT = JDT 2454400.5
T 2007 Oct. 28.7595 TT                                  MPC
q   0.402372             (2000.0)            P               Q
z  -0.000216       Peri.  153.7117      +0.9137883      +0.3906744
+/-0.000018       Node   172.8882      -0.0827780      -0.0889004
e   1.000087       Incl.  116.0843      +0.3976667      -0.9162261
Date                   TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase   m1    m2

2007 09 27    11 55.28   +27 58.8    1.595    0.877    29.6    34.4  10.4
2007 10 02    12 11.74   +27 36.5    1.440    0.782    31.2    41.6   9.7
2007 10 07    12 32.23   +26 46.7    1.277    0.686    32.3    51.0   8.9
2007 10 12    12 58.53   +24 59.7    1.109    0.594    32.2    63.6   8.0
2007 10 17    13 32.90   +21 13.2    0.944    0.509    30.3    80.6   6.9
2007 10 22    14 16.80   +13 34.6    0.801    0.442    25.7   102.5   6.0
2007 10 27    15 06.90   +00 23.5    0.721    0.405    20.4   121.4   5.4
2007 11 01    15 53.05   -15 42.3    0.739    0.412    21.8   116.3   5.5
2007 11 06    16 27.14   -29 00.4    0.842    0.459    27.5    94.7   6.2
2007 11 11    16 49.82   -37 56.7    0.983    0.533    31.3    75.0   7.2
2007 11 16    17 05.21   -43 49.1    1.133    0.620    33.1    60.6   8.2
2007 11 21    17 16.54   -47 52.8    1.276    0.714    33.8    50.4   9.1
2007 11 26    17 25.69   -50 52.6    1.410    0.810    34.0    43.0   9.8
2007 12 01    17 33.69   -53 13.6    1.534    0.905    34.1    37.6  10.5



http://www.spaceweather.com/


COMET LONEOS: "Comet LONEOS (C/2007 F1) is here!" reports Tony Cook of Leeds, UK, who took this picture on Sept. 30th:

"Over the next month this comet is predicted to increase in brightness to 4th magnitude--barely visible to the naked eye but an easy target for backyard telescopes," he says.

Comet LONEOS is not a frequent visitor to the inner solar system. One analysis suggests it was last in the neighborhood 42,000 years ago. It's equally possible, however, that the comet has never been close to the sun before; this could be its first plunge. The uncertainty adds suspense to Oct. 29th when LONEOS will approach the sun almost as close as Mercury. Will fresh veins of ice newly heated by sunlight burst forth to produce surprisingly bright jets and clouds? Stay tuned!

Cook's Sept. 30th image "was taken under bright moonlight just before dawn," he adds. "Even under these difficult conditions a fine but faint linear tail can be seen. As the moon departs and the comet gets closer to the sun, the view can only get better and brighter!"

Astrophotographers, if you wish to try to catch the comet, look below the handle of the Big Dipper for a green 8th magnitude fuzzball.

下了快一周的雨了～

26 27刚好周末  估计有希望看看！！

顺便问一下
没有跟踪
曝上几十秒能出来不？

条件的确很差

傍晚西方低空，最亮4等。。。这还有什么希望

4等实在是有些暗，我们这里天气最好的时候极限星等也不过4.5