我觉得好象有点类似“再发新星”啊！::42::
谢谢叶教授和苏老师，我会将二位的话转载到校刊上~~
彗核的物质成分和内部结构又是怎样的呢？目前还不很清楚。从彗核的质量和大小，可以初步算出它的平均密度，如，哈雷彗星的平均密度约0.3克/立方厘米
http://baike.baidu.com/view/431237.htm
另外：
为了产生增亮~1M倍的效果，彗星大概耗去了30t的物质
这个是怎么估算的？
以及持续几个星期甚至几个月的高亮度需要多少物质？
撞击产生的爆发能持续多久?和彗星的成分结构有关系吗？
[ 本帖最后由 suhuasky 于 2007-10-26 17:29 编辑 ]
彗星的地质变化？
或者是因为彗星结构松动在动力学和热力学的因素下坍塌？
[ 本帖最后由 suhuasky 于 2007-10-26 17:34 编辑 ]
我还是认为不排除撞击的可能性，小龙给出的彗星直径3.4公里左右，如果是直径十米或二十米甚至更大些的产生的撞击呢？何况现在彗星在小行星带区域，撞击产生的爆发持续多久和彗星的结构、成分肯定有直接的关系。
要验证也不难吧，小龙能不能找找哪个小行星轨道和彗星香蕉？
::070821_20.jpg:: ::070821_20.jpg::
呜呜 西安 阴天
嘿嘿，我昨天拍了，今天阴天，赚到了
原帖由 活动星图 于 2007-10-26 18:00 发表 http://www.astronomy.com.cn/bbs/images/common/back.gif
要验证也不难吧，小龙能不能找找哪个小行星轨道和彗星香蕉？
无法验证！在主带上几十米大小的小行星目前还观测不到。::42::
囧神在上。。。
麻烦您把前边的帖子，从头到尾，稍微长一些的都好好看看，答案那里有。
最新报告
Hello Everyone,
I was able to easily observe Comet Holmes this morning from Edmond
Oklahoma USA despite light pollution and nearby full moon. My naked-
eye magnitude estimate is 2.3 using comparison stars of 1.8 (Alpha Per)
and 3.0 (Delta Per). Coma was visible through very small 10x25
binoculars. Time of observation 0915 UT.
Russ
（2.3等，10月26日09：15UT USA ）
特殊处理过的彗核精细结构照片
日本彗星专家Seiichi Yoshida 网站关于17的资料：
Surprisingly, a great outburst occured on Oct. 24 and now it becomes so bright as 2.5 mag, visible with naked eyes! Almost stellar, so it looks like a nova. It was observed as 14.5 mag in July, then it had been fading down to 17 mag until mid October as predicted. This comet was also in great outburst at the discovery in 1892 and became so bright as 5 mag. At that time, the comet faded after the first outburst, but soon brightened again in the second outburst. The further brightness is uncertain. But the comet will be observable in excellent condition for a while after this.
Date(TT)R.A. (2000) Decl. Delta r Elong.m1 Best Time(A, h)Oct. 20 3 56.82 49 41.6 1.648 2.421 130 16.0 2:06 (180, 75)Oct. 27 3 51.15 50 16.7 1.630 2.447 136 2.5 1:33 (180, 75) The following orbital elements are taken from MPC 51822: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. m1 = 1.5 + 5 log d + 35 log r[ ,172.5]( - 2007 Oct. 24)
m1 = -18 + 5 log d + 50 log r(2007 Oct. 24 - ) * Gray curve is:m1 = 1.5 + 5 log d + 35 log r
[ 本帖最后由 suhuasky 于 2007-10-26 22:17 编辑 ]
北京大雾！可恶！听说明晚阴转晴！但愿吧！
目前大连能见度20米::070821_20.jpg::
每日彗星预报（亮度是按老数据，可自行推算）
Ephemeris of comet 17P Holmes
日期Geo R.A.Geo DecR (AU)距离El ? Mag
26 十月 200703h 52m 06.9s+50°12' 42"2.44361.6325135.616.9
27 十月 200703h 51m 12.0s+50°16' 46"2.44751.6304136.316.9
28 十月 200703h 50m 15.3s+50°20' 30"2.45131.6285137.116.9
29 十月 200703h 49m 16.7s+50°23' 54"2.45521.6269137.816.9
30 十月 200703h 48m 16.3s+50°26' 58"2.45901.6254138.516.9
31 十月 200703h 47m 14.3s+50°29' 41"2.46291.6240139.216.9
01 十一月 200703h 46m 10.6s+50°32' 03"2.46681.6229139.916.9
02 十一月 200703h 45m 05.5s+50°34' 03"2.47071.6220140.616.9
03 十一月 200703h 43m 59.0s+50°35' 42"2.47461.6213141.316.9
04 十一月 200703h 42m 51.2s+50°36' 58"2.47851.6208142.017.0
05 十一月 200703h 41m 42.2s+50°37' 53"2.48241.6204142.617.0
06 十一月 200703h 40m 32.2s+50°38' 25"2.48631.6203143.217.0
07 十一月 200703h 39m 21.2s+50°38' 35"2.49031.6205143.817.0
08 十一月 200703h 38m 09.4s+50°38' 22"2.49421.6208144.417.0
09 十一月 200703h 36m 56.9s+50°37' 47"2.49821.6213145.017.0
10 十一月 200703h 35m 43.9s+50°36' 49"2.50211.6221145.517.0
11 十一月 200703h 34m 30.3s+50°35' 29"2.50611.6231146.017.0
12 十一月 200703h 33m 16.5s+50°33' 46"2.51011.6243146.517.1
13 十一月 200703h 32m 02.5s+50°31' 42"2.51411.6257147.017.1
14 十一月 200703h 30m 48.4s+50°29' 15"2.51801.6274147.417.1
15 十一月 200703h 29m 34.4s+50°26' 26"2.52201.6293147.817.1
16 十一月 200703h 28m 20.5s+50°23' 15"2.52611.6314148.217.1
17 十一月 200703h 27m 07.0s+50°19' 44"2.53011.6338148.517.1
18 十一月 200703h 25m 53.9s+50°15' 51"2.53411.6364148.817.1
19 十一月 200703h 24m 41.3s+50°11' 38"2.53811.6392149.017.1
20 十一月 200703h 23m 29.4s+50°07' 05"2.54221.6423149.217.2
21 十一月 200703h 22m 18.3s+50°02' 11"2.54621.6456149.417.2
22 十一月 200703h 21m 08.1s+49°56' 59"2.55031.6491149.617.2
23 十一月 200703h 19m 58.8s+49°51' 28"2.55431.6529149.717.2
24 十一月 200703h 18m 50.7s+49°45' 38"2.55841.6569149.717.2
25 十一月 200703h 17m 43.7s+49°39' 31"2.56251.6611149.717.2
26 十一月 200703h 16m 38.0s+49°33' 07"2.56651.6656149.717.3
27 十一月 200703h 15m 33.7s+49°26' 27"2.57061.6703149.617.3
28 十一月 200703h 14m 30.7s+49°19' 30"2.57471.6753149.517.3
29 十一月 200703h 13m 29.3s+49°12' 18"2.57881.6805149.417.3
30 十一月 200703h 12m 29.5s+49°04' 51"2.58291.6860149.217.3
01 十二月 200703h 11m 31.3s+48°57' 11"2.58701.6916149.017.3
02 十二月 200703h 10m 34.8s+48°49' 16"2.59121.6976148.717.4
03 十二月 200703h 09m 40.2s+48°41' 09"2.59531.7037148.417.4
04 十二月 200703h 08m 47.4s+48°32' 50"2.59941.7101148.117.4
05 十二月 200703h 07m 56.5s+48°24' 20"2.60361.7168147.717.4
06 十二月 200703h 07m 07.6s+48°15' 39"2.60771.7236147.317.4
07 十二月 200703h 06m 20.7s+48°06' 49"2.61181.7307146.917.4
08 十二月 200703h 05m 35.9s+47°57' 49"2.61601.7381146.417.5
09 十二月 200703h 04m 53.1s+47°48' 41"2.62021.7457145.917.5
10 十二月 200703h 04m 12.6s+47°39' 25"2.62431.7535145.417.5
11 十二月 200703h 03m 34.1s+47°30' 02"2.62851.7615144.817.5
12 十二月 200703h 02m 57.9s+47°20' 33"2.63271.7698144.317.6
13 十二月 200703h 02m 23.9s+47°10' 59"2.63681.7782143.717.6
14 十二月 200703h 01m 52.0s+47°01' 20"2.64101.7870143.117.6
15 十二月 200703h 01m 22.5s+46°51' 36"2.64521.7959142.517.6
16 十二月 200703h 00m 55.2s+46°41' 49"2.64941.8050141.817.6
17 十二月 200703h 00m 30.1s+46°32' 00"2.65361.8144141.117.6
18 十二月 200703h 00m 07.3s+46°22' 08"2.65781.8240140.517.7
19 十二月 200702h 59m 46.7s+46°12' 15"2.66201.8338139.817.7
20 十二月 200702h 59m 28.4s+46°02' 20"2.66621.8438139.117.7
21 十二月 200702h 59m 12.3s+45°52' 25"2.67041.8540138.417.7
22 十二月 200702h 58m 58.4s+45°42' 31"2.67471.8644137.617.8
23 十二月 200702h 58m 46.8s+45°32' 37"2.67891.8750136.917.8
24 十二月 200702h 58m 37.3s+45°22' 44"2.68311.8859136.117.8
25 十二月 200702h 58m 30.0s+45°12' 53"2.68731.8969135.417.8
26 十二月 200702h 58m 24.8s+45°03' 04"2.69161.9081134.617.9
27 十二月 200702h 58m 21.8s+44°53' 17"2.69581.9194133.917.9
28 十二月 200702h 58m 20.8s+44°43' 33"2.70011.9310133.117.9
29 十二月 200702h 58m 22.0s+44°33' 53"2.70431.9428132.317.9
30 十二月 200702h 58m 25.2s+44°24' 16"2.70861.9547131.517.9
31 十二月 200702h 58m 30.4s+44°14' 43"2.71281.9669130.718.0
01 一月 200802h 58m 37.7s+44°05' 14"2.71711.9792129.918.0
02 一月 200802h 58m 46.9s+43°55' 50"2.72131.9916129.118.0
03 一月 200802h 58m 58.2s+43°46' 31"2.72562.0043128.318.0
04 一月 200802h 59m 11.4s+43°37' 17"2.72992.0171127.518.1
05 一月 200802h 59m 26.5s+43°28' 09"2.73412.0301126.718.1
06 一月 200802h 59m 43.5s+43°19' 07"2.73842.0432125.918.1
07 一月 200803h 00m 02.4s+43°10' 10"2.74272.0565125.118.1
08 一月 200803h 00m 23.1s+43°01' 20"2.74702.0700124.318.2
09 一月 200803h 00m 45.7s+42°52' 37"2.75122.0836123.518.2
10 一月 200803h 01m 10.0s+42°44' 00"2.75552.0974122.718.2
11 一月 200803h 01m 36.1s+42°35' 30"2.75982.1113121.918.2
12 一月 200803h 02m 03.9s+42°27' 07"2.76412.1253121.018.3
13 一月 200803h 02m 33.4s+42°18' 51"2.76842.1395120.218.3
14 一月 200803h 03m 04.6s+42°10' 42"2.77272.1538119.418.3
15 一月 200803h 03m 37.4s+42°02' 41"2.77702.1683118.618.3
16 一月 200803h 04m 11.8s+41°54' 47"2.78132.1829117.818.4
17 一月 200803h 04m 47.8s+41°47' 00"2.78562.1976117.018.4
18 一月 200803h 05m 25.3s+41°39' 22"2.78992.2124116.218.4
19 一月 200803h 06m 04.4s+41°31' 50"2.79422.2273115.418.4
20 一月 200803h 06m 44.9s+41°24' 27"2.79852.2424114.618.5
21 一月 200803h 07m 26.9s+41°17' 11"2.80282.2576113.818.5
22 一月 200803h 08m 10.3s+41°10' 02"2.80712.2728113.018.5
23 一月 200803h 08m 55.0s+41°03' 02"2.81142.2882112.218.5
24 一月 200803h 09m 41.1s+40°56' 08"2.81582.3037111.418.6
25 一月 200803h 10m 28.5s+40°49' 23"2.82012.3193110.618.6
26 一月 200803h 11m 17.3s+40°42' 45"2.82442.3350109.818.6
27 一月 200803h 12m 07.3s+40°36' 14"2.82872.3507109.018.6
28 一月 200803h 12m 58.5s+40°29' 51"2.83302.3666108.218.6
29 一月 200803h 13m 51.0s+40°23' 35"2.83732.3826107.418.7
30 一月 200803h 14m 44.7s+40°17' 26"2.84172.3986106.618.7
31 一月 200803h 15m 39.6s+40°11' 25"2.84602.4147105.818.7
01 二月 200803h 16m 35.6s+40°05' 31"2.85032.4309105.118.8
02 二月 200803h 17m 32.8s+39°59' 44"2.85472.4472104.318.8
引用: suhuasky 在文中说道:
核的物质成分和内部结构又是怎样的呢？目前还不很清楚。从彗核的质量和大小，可以初步算出它的平均密度，如，哈雷彗星的平均密度约0.3克/立方厘米
http://baike.baidu.com/vi...
忘记加一个reference：这是孟奂的估计结果，这次增亮大约耗去了0.3%的物质。
如果密度更低的话那就更没戏了，撞击的小行星肯定更小。
不过从我们掌握的彗星资料来看，撞击也好，内部因素也好，概率都太小了。除非17P结构很特殊。
引用: suhuasky 在文中说道:
特殊处理过的彗核精细结构照片
http://yeiht.y234.cn/wordpress/wp-gallery/Lulin-Sky-Survey/17p_071025_15.PNG
这张的喷流更精细一些，再看看昨晚的怎么样。可能是个测rotation period的好机会……