Weekly Information about Bright Comets (2010 Dec. 18: North)

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Updated on December 31, 2010
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Best time and the azimuth, altitude (A,h) are at lat. 35 deg in the Northern Hemisphere.
Azimuth indicates 0 for south, 90 for west, 180 for north, 270 for east.

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* 103P/Hartley 2

It approached to the earth down to 0.12 A.U. and brightened up to 4.6 mag in October (Oct. 18, Juan Jose Gonzalez). It was very large, double of the full moon, and very bright, visible with naked eyes. Now it is fading, but still bright as 8.4 mag (Dec. 18, Katsumi Yoshimoto). After this, it keeps observable for a long time until 2011 June when it fades down to 17 mag.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   7 30.06  -18 14.0   0.379   1.264   130    7.7   1:45 (  0, 37)  
Dec. 25   7 24.17  -17 54.3   0.421   1.316   135    8.2   1:12 (  0, 37)  

* 9P/Tempel 1

The condition in this apparition is bad. It keeps unobservable for a while. In the Southern Hemisphere, it will appear in the morning sky at 12.5 mag in February, then it keeps observable while fading gradually. In the Northern Hemisphere, it is not observable until when it fades down to 15 mag.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  16 13.43  -19  8.8   2.409   1.532    20   12.5   5:31 (295,  1)  
Dec. 25  16 36.16  -20 31.1   2.382   1.522    22   12.4   5:35 (297,  2)  

* P/2010 V1 ( Ikeya-Murakami )

Bright new comet discovered visually by Kaoru Ikeya and Shigeki Murakami. Now it is 13.7 mag (Dec. 18, D. Chestnov and A. Novichonok). Its envelope similar to 17P/Holmes is getting diffuse rapidly. In the Northern Hemisphere, it keeps observable for a long time after this in the morning low sky. It locates very low in the Southern Hemisphere, but it will be getting higher gradually.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  14 24.84  -15 43.3   2.208   1.694    46   13.2   5:31 (310, 22)  
Dec. 25  14 41.51  -17 32.8   2.185   1.718    49   13.9   5:35 (315, 23)  

* C/2009 P1 ( Garradd )

Already very bright as 11.5 mag (Nov. 24, Juan Jose Gonzalez). It is expected to keep so bright as 6-8 mag for a long time from 2011 to 2012, and to be observable in good condition in the Northern Hemisphere. In 2010, it is observable in good condition in the Southern Hemisphere while brightening slowly. It locates low in the Northern Hemisphere, but it keeps observable until the end of 2010.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  21 55.81  -29 39.2   5.092   4.622    56   13.3  18:21 ( 30, 18)  
Dec. 25  21 57.09  -28 40.4   5.124   4.558    50   13.3  18:24 ( 36, 16)  

* 29P/Schwassmann-Wachmann 1

Now it is 13.8 mag (Dec. 18, D. Chestnov and A. Novichonok).

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  11 16.60   -0 22.5   6.069   6.242    95   13.9   5:31 (  0, 55)  
Dec. 25  11 17.29   -0 36.9   5.957   6.243   102   13.8   5:04 (  0, 54)  

* C/2009 Y1 ( Catalina )

Now it is 12.9 mag, much brighter than originally expected and visible visually (Dec. 4, Seiichi Yoshida). In the Northern Hemisphere, it will be observable at 13-14 ag in good condition from autumn to winter. In the Southern Hemisphere, it will be unobservable until 2011 spring.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  20 25.61   44  4.6   2.593   2.561    77   13.9  18:21 (119, 47)  
Dec. 25  20 42.75   40 53.0   2.654   2.549    73   13.9  18:24 (116, 44)  

* C/2009 K5 ( McNaught )

It brightened up to 7.9 mag in April and May (May 5, Juan Jose Gonzalez). Now it is fading. The central part is so faint as 15-16 mag. However, extremely faint large coma extends, and the total brightness is still bright as 12.5 mag (Dec. 5, Uwe Pilz). It keeps observable for a long time until when it fades out in the Northern Hemisphere. It is not observable in the Southern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   5  7.20   44 26.7   2.382   3.314   157   14.0  23:18 (180, 81)  
Dec. 25   4 51.45   42 21.5   2.469   3.384   154   14.3  22:35 (180, 83)  

* (596) Scheila

Big asteroid discovered in 1906. It suddenly showed the cometary activity on Dec. 11. Now it is 13.4 mag (Dec. 11, S. Larson), brighter than quiescent phase by 1 mag. The coma extends up to 5 arcmin. It is very bright as 11.5 mag visually (Dec. 17, Juan Jose Gonzalez).

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   9 59.54   28 43.7   2.457   3.099   122   14.2   4:14 (  0, 84)  
Dec. 25   9 59.86   29 30.2   2.371   3.089   129   14.0   3:47 (  0, 84)  

* 10P/Tempel 2

It has kept bright as 8.5 mag since July until September. Now it is fading, but it is still bright as 12.5 mag (Dec. 4, Katsumi Yoshimoto). It will be visible visually until December.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   1 21.79   -8 15.9   1.612   2.146   109   14.2  19:34 (  0, 47)  
Dec. 25   1 27.63   -6 39.5   1.729   2.189   104   14.5  19:13 (  0, 48)  

* C/2010 B1 ( Cardinal )

Now it is 13.8 mag and visible visually (Nov. 13, Juan Jose Gonzalez). It keeps observable at 14-15 mag in good condition from autumn to next spring.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   6 27.01   -1 48.8   2.078   2.986   152   14.4   0:43 (  0, 53)  
Dec. 25   6 10.93   -4 29.2   2.069   2.974   152   14.3  23:53 (  0, 50)  

* C/2006 W3 ( Christensen )

It reached up to 7.7 mag in 2009 summer (2009 Aug. 13, Chris Wyatt). It is fading now. It will never be observable again in the Northern Hemisphere. It becomes low also in the Southern Hemisphere. Therefore, no observations have been reported since October. But it will be getting higher after January. In the Southern Hemisphere, it keeps observable in good condition until 2011 autumn when it becomes fainter than 18 mag.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  17 47.84  -48 48.2   6.599   5.727    25   14.9  18:21 ( 48,-29)  
Dec. 25  17 52.32  -49 11.1   6.642   5.775    26   14.9   5:35 (313,-26)  

* C/2009 F4 ( McNaught )

Now it is 14.8 mag (June 23, Hidetaka Sato). It keeps bright as 14-15 mag for a long time after this until 2013. It is not observable in the Northern Hemisphere. In the Southern Hemisphere, it locates low now. But it will be getting higher gradually after December. It must be bright, however, no observations have been reported since early July.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  15 39.37  -56 42.9   6.836   6.116    40   15.0   5:31 (328,-17)  
Dec. 25  15 45.87  -57 44.1   6.773   6.093    43   15.0   5:35 (331,-15)  

* 65P/Gunn

It brightened up to 11.5 mag in July (July 18, Juan Jose Gonzalez). Now it is 14.9 mag (Nov. 25, A. Novichonok and D. Chestnov). Fading slowly. It is observable in excellent condition in the Southern Hemisphere. It will be getting lower in the evening sky gradually, and will be unobservable in January.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  21 56.13  -22 18.3   3.373   2.973    58   15.1  18:21 ( 34, 25)  
Dec. 25  22  5.62  -21 15.5   3.472   2.994    53   15.2  18:24 ( 39, 23)  

* C/2006 S3 ( LONEOS )

Now it is 14.5 mag and visible visually (Sept. 30, Alan Hale). It will be observable at 13-14 mag for a long time from 2011 to 2012. It will be getting lower gradually in the evening sky after this. It will be unobservable in November in the Southern Hemisphere, or in December in the Northern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  20 10.62   -7 15.8   7.015   6.283    39   15.2  18:21 ( 65, 20)  
Dec. 25  20 11.94   -7 19.6   7.058   6.254    32   15.2  18:24 ( 70, 14)  

* 43P/Wolf-Harrington

Now it is 15.1 mag (Dec. 18, D. Chestnov and A. Novichonok). It has a long tail by CCD observations. It keeps observable after this while fading gradually.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  12 47.30  -20 38.7   2.393   2.212    67   15.3   5:31 (335, 30)  
Dec. 25  12 55.53  -21 55.1   2.359   2.261    72   15.4   5:35 (342, 31)  

* C/2010 FB87 ( WISE-Garradd )

Now it is 14.5 mag (Nov. 8, K. Hills), much brighter than originally expected. It keeps 16 mag until 2011 spring. It keeps observable in good condition in the Southern Hemisphere. But in the Northern Hemisphere, it locates very low in 2011 spring only.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  10  9.24  -68 59.3   2.946   2.873    76   15.5   4:25 (  0,-14)  
Dec. 25   9 37.70  -69 45.8   2.887   2.884    79   15.5   3:26 (  0,-15)  

* C/2008 FK75 ( Lemmon-Siding Spring )

Now it is 15.2 mag (Nov. 27, A. Novichonok and D. Chestnov). It will be fading very slowly after this. In the Northern Hemisphere, it keeps observable for a long time until 2012 spring when it fades down to 17-18 mag. It will not be observable in the Southern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  19 17.98   31 50.5   4.971   4.557    59   15.6  18:21 (109, 31)  
Dec. 25  19 28.18   31 53.6   5.007   4.565    58   15.6  18:24 (112, 27)  

* 240P/2010 P1 ( NEAT )

Now it is 14.0 mag and visible visually (Dec. 17, Juan Jose Gonzalez). It is observable at 15 mag in good condition from autumn to winter. It locates somewhat low in the Southern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   6 45.76   36 54.0   1.251   2.204   160   15.7   1:02 (180, 88)  
Dec. 25   6 38.77   38 42.8   1.257   2.219   163   15.8   0:27 (180, 86)  

* (3200) Phaethon

It passed the perihelion on Nov. 25. In the Northern Hemisphere, it appeared in the evening sky. It keeps observable until February when it becomes fainter than 18 mag. It will not be observable in the Southern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  19 59.43   -7 17.3   1.146   0.689    36   15.9  18:21 ( 67, 19)  
Dec. 25  20 45.92   -3  0.9   1.230   0.831    42   16.3  18:24 ( 68, 24)  

* C/2010 G2 ( Hill )

A small outburst occured and it brightened by 2 mag, up to 16.1 mag, on 2010 Aug. 31 (Bernhard Haeusler). Now it is 15.5 mag (Dec. 4, Ken-ichi Kadota). It will brighten up to 11.5 mag in 2011 autumn. In the Northern Hemisphere, it keeps observable for a long time until 2012 spring. In the Southern Hemisphere, it is not observable until 2011 November.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  16 26.65   21 27.6   4.101   3.525    48   16.0   5:31 (259, 22)  
Dec. 25  16 33.86   22 29.0   3.987   3.466    51   15.9   5:35 (261, 27)  

* C/2010 A4 ( Siding Spring )

Now it is 16.0 mag (Dec. 4, D. Chestnov & A. Novichonok). It will be fading slowly after this. It is not observable at all in the Northern Hemisphere. It is observable in good condition in the Southern Hemisphere, but it will be getting lower gradually after January.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   0 36.94  -68 35.9   2.956   2.832    73   16.4  18:48 (  0,-13)  
Dec. 25   0 25.00  -64 48.8   3.030   2.851    70   16.5  18:24 (  2,-10)  

* 123P/West-Hartley

Now it is 16.8 mag (Nov. 27, A. Novichonok and D. Chestnov). In the Northern Hemisphere, it keeps observable in good condition until 2011 spring when it brightens up to 16 mag. In the Southern Hemisphere, it keeps locating low.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   5 14.73   37 44.8   1.642   2.604   164   17.0  23:26 (180, 87)  
Dec. 25   5  6.91   38 10.2   1.631   2.576   159   16.9  22:51 (180, 87)  

* C/2009 K3 ( Beshore )

It was observed only during 3 days in 2009 May, then it has been lost. The ephemeris says that it passes the perihelion in 2011 January and it will be observable at 17 mag. But actually, it will not be found.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   8  2.91  -18  7.3   3.245   3.906   126   17.0   2:19 (  0, 37)  
Dec. 25   7 48.50  -18 37.6   3.178   3.904   131   16.9   1:37 (  0, 36)  

* C/2008 S3 ( Boattini )

Now it is 17.5 mag (Nov. 27, Ken-ichi Kadota). It keeps 17 mag for a long time from 2009 to 2012. It is observable in good condition in the Northern Hemisphere. It locates somewhat low in the Southern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   1  0.41   16  6.6   7.634   8.085   114   17.0  19:13 (  0, 71)  
Dec. 25   0 57.59   15 47.9   7.749   8.080   106   17.0  18:42 (  0, 71)  

* C/2010 S1 ( LINEAR )

Now it is 16.9 mag (Nov. 28, A. Novichonok and D. Chestnov). It is expected to be 15 mag and will be observable in good condition in 2013. It is observable in good condition in the Northern Hemisphere, but not observable in the Southern Hemisphere now.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   1 55.38   59 39.0   7.817   8.442   126   17.2  20:07 (180, 65)  
Dec. 25   1 49.09   59  1.6   7.844   8.410   122   17.2  19:34 (180, 66)  

* 203P/2008 R4 ( Korlevic )

Now it is 17.4 mag (Dec. 9, Tzec Maun observatory). It tends to be brightest after the perihelion passage. At the discovery in 1999, it became brightest one year after the perihelion passage. At this time, it became brightest three months after the perihelion passage, then it is fading. It keeps observable in good condition at 18 mag until may.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  10 34.60    7  2.6   3.147   3.578   108   17.4   4:49 (  0, 62)  
Dec. 25  10 35.61    6 49.4   3.066   3.593   114   17.3   4:23 (  0, 62)  

* 2008 YB3

Large Centaur-type asteroid. It keeps observable at 17-18 mag for a long time until 2013.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   8 10.03  -18 22.5   5.883   6.495   124   17.4   2:25 (  0, 37)  
Dec. 25   8  5.51  -18  1.8   5.814   6.493   130   17.4   1:53 (  0, 37)  

* C/2007 VO53 ( Spacewatch )

Now it is 17.3 mag (Oct. 2, Ken-ichi Kadota). It is fading slowly. In the Northern Hemisphere, it keeps observable in good condition until 2011 summer. It is not observable in the Southern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  17  3.71   44 14.8   5.461   5.177    68   17.4   5:31 (233, 26)  
Dec. 25  17  9.31   43 46.0   5.471   5.196    68   17.4   5:35 (235, 30)  

* C/2005 L3 ( McNaught )

It had been bright as 13-14 mag for a long time from 2007 to 2009. Now it is fading, but it is 15.3 mag still now (Dec. 10, D. Chestnov and A. Novichonok), much brighter than predicted. It keeps observable at 16-17 mag in good condition until next spring.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  11 58.94   36 41.6   8.999   9.229   100   17.6   5:31 (256, 81)  
Dec. 25  11 57.45   37 11.9   8.932   9.264   106   17.6   5:35 (223, 87)  

* 31P/Schwassmann-Wachmann 2

Now it is 18.1 mag (Dec. 13, Tzec Maun Observatory). It was observed at 18 mag in winter between 2009 and 2010. It will be observable again at 18 mag in good condition from winter to spring in 2011.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18  10 56.30    9 39.6   3.064   3.440   104   17.7   5:11 (  0, 65)  
Dec. 25  10 58.72    9 36.4   2.970   3.442   110   17.6   4:46 (  0, 65)  

* 241P/2010 P2 ( LINEAR )

Now it is 17.3 mag (Dec. 14, Catalina Sky Survey). It has already passed the perihelion, however, it tends to be brightest after the perihelion passage. In the Northern Hemisphere, it will be observable at 17.5 mag in good condition until the end of 2010. It locates extremely low in the Southern Hemisphere.

Date(TT)  R.A. (2000) Decl.   Delta     r    Elong.  m1   Best Time(A, h)  
Dec. 18   9 22.23   19 58.3   1.651   2.395   128   17.8   3:37 (  0, 75)  
Dec. 25   9 18.61   19 14.2   1.621   2.432   136   17.8   3:06 (  0, 74)  

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