Monthly Information about Comets in December 1996
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Updated on December 10, 1996 |
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Comets Ranking
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Here is the ranking of comets in December, 1996.
Comet C/1995 O1 (Hale-Bopp), the probable greatest comet in this century, had seemed to go faint a bit in September and surprised us. But it began to brighten again after that and reached 4.5 mag now. It comes to conjunction with Sun through this and next month, then it will appears at dawn in mid January and the highlight comes. Comet C/1996 Q1 ( Tabur ) had been brightening rapidly and reached 5 mag in late September. But, to be very surprised, it turned to go faint in October. It stopped brightening just after October came and had been stable with 5-6 mag until mid October, and it has suddenly faded away on 20th and reached to 9 mag in a few days. Now it is 10 mag or fainter, extremely diffused. Though 96P/Machholz 1 and 85P/Boethin have not been observed yet at this return, they have already closed to Sun and set under the horizon. We have another chance to observe 85P/Boethin in next autumn, but it is almost impossible to see 96P/Machholz 1 this time.
Other faint comets are as follows.
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Explanations
Comet Hale-Bopp, the probable greatest comet in this century, has
stopped its favorable brightening until July in August, then it seemed
to go faint a bit as 6 mag and made us impatient in September. But it
began to brighten again after that. It reached about 4.5 mag in late
November and early December.
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C/1996 J1 (Evans-Drinkwater) is a new comet discovered on May 16 with
magnitude about 16. It had been observed until July with magnitude 13.
Then it closes to the sun. It will pass the perihelion on Dec. 30 but
is still not observable. The predicted magnitude is 9 mag.
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Comet C/1996 Q1 ( Tabur ) is a new comet discovered on Aug. 19 by
Mr. Tabur in Australia as 10 mag. It had been brightening more rapidly
than expected in September and reached to 5 mag and became a naked-eye
object in late September. The change of magnitude in this period is
along the equation:
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81P/Wild 2, which will pass the perihelion on May 6, 1997, has been
brightening so rapidly. It was about 16.5 mag in September, 15 mag in
October, 14 mag in November and then reached 13 mag in early
December. Observations with eyes are also reported. The change of the
magnitude is along the equation:
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116P/Wild 4, which has been bright as 12 mag in this spring, moves
from Libra to Scorpius in December and enters Ophiuchus in January. It
is still at conjunction with the sun and not observable.
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126P/IRAS is a periodic comet discovered in 1983 by a satellite and
this is the first return. It had not been recovered for a while
because it was not observable in the Northern Hemisphere, but finally
recovered on Aug. 8. The magnitude is 13, same as expected. It began
to be seen in the Northern Hemisphere after late September.
Unfortunately the total magnitude has reached only 12 mag in
October. It has already passed the perihelion on Oct. 29 and been
getting faint. It was 13 mag in early December.
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118PShoemaker-Levy 4, which is in its first return now, will pass the
perihelion on Jan. 12. This return is best, just at opposition around
the perihelion date.
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22P/Kopff has already passed the perihelion on July 2. The condition
of this return is best, almost opposition around the perihelion day,
and reached 8 mag. Though it keeps high altitude after that for a
while, only a few observations were reported after mid September
somehow. They show the comet has been coming faint as same as
pre-perihelion brightening. It was observed as 13.5 mag in early
December. The total light curve of this return is along the equation:
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Comet 85P/Boethin, which will pass the perihelion on Apr. 17, 1997,
has finally set in the west not been observable already though it has
not been observed in this return yet. The condition of this return is
quite worst. It should be 9.5 mag around the perihelion but too close
to the sun to see it. It will appear again at dawn next October 1997,
but then it is as faint as 17 mag.
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22P/Schwassmann-Wachmann 1 has bursted out in February during the last
season. It reached about 11 mag, then became faint and diffused and
set in the west as 14 mag in June.
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65P/Gunn has already passed the perihelion on July 24. The condition
of this return is good and it had been observed as 12 mag from May to
July. It has been going gradually faint after this and observed as
13.5 mag in September. But no observations succeeded after that.
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A new comet C/1996 P2 (Russell-Watson) was discovered on August 10 as
13 mag in the southern constellation Sculptor. It has already passed
the perihelion on Mar. 1 and the perihelion distance is as far as 2.0
AU, so it is going fainter slowly.
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Comet 46P/Wirtanen, which will pass the perihelion on Mar. 14, has
been observed as 19 mag from July and October, which is much fainter
than expected. But it seemed to begin brightening recently. It was
15.5 mag in December. However this comet will be bright as only 12-13
mag in next spring if the the brightening keeps the current pace. Yet
this comet tends to brighten so rapidly around perihelion date, please
watch out the magnitude.
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124P/Mrkos is returning for the first time. It has been already
recovered in October 1995 as 19.5 mag, but no observations are
reported since it because it has been too close to the Sun during
1996. It is still too low in the southeast sky at dawn this month and
impossible to observe it. The condition of this return is so bad and
no one tell anything on it. But the perihelion date is Nov. 9 and it
is brightest now as 15 mag.
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A new comet discovered on Sept. 7 as 14 mag. The perihelion date is
Aug. 28, so it was discovered under the best condition, around
opposition just on perihelion day. It was seen overhead at midnight in
September in the Northern Hemisphere and the magnitude was around
11.5-12.5. But it moved southwards rapidly and became to be seen only
in the evening sky. So only few observations were reported after mid
October. It seemed to fade awar more rapidly, 14 mag in early November
and 16 mag in early December.
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Comet 121P/Shoemaker-Holt 2 was discovered in 1989 and is now in its
first return. If the comet had kept the brightness at the discovery,
it would have been observed as 12-13 mag for a while. But actually, it
was recovered in November 1995 as 18 mag, which was 5 mag fainter than
expected. Then it has been as 19 mag and becomes at conjunction with
the sun around the perihelion on Aug. 20. However, after it began to
appear again at dawn in October, it was observed as 16 mag, which was
2-3 mag brighter than before-perihelion. In 1989 it was discovered
after perihelion, too. So maybe this is a comet which becomes brighter
after perihelion.
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Faint Comets
| C/1996 B2 (Hyakutake), which became one of the greatest comets as 0 mag with 100 deg long tail in March and April, is now not seen in the Northern Hemisphere. It has been observed in the Southern Hemisphere after the perihelion day on May 1, and reached 12 mag in early September. But no observations has been reported after that and recent status is so unclear. The predicted magnitude is about 16. It is is Corona Austrina in December and January. Though it was low both at dusk and at dawn even in the Southern Hemisphere in October and November, the altitude at dawn becomes higher after this. But maybe no more observations are reported. |
| 95P/Chiron, whose period is about 50 years and which is also registered as an asteroid (2060), begins to appear at dawn again. It passed the perihelion in February and was observed as 15 mag in the last season. But the perihelion distance is so large and the magnitude changes slightly. It will be 15 mas again when it is at opposition in next spring. We can trace it for a few years at least. It is just in the south of Spica now. |
| 57P/du Toit-Neujmin-Delporte, which was expected to be as 18-19 mag from pre-perihelion observations, has bursted out and been as bright as 12-13 mag in late July. Then it has been stable with magnitude about 15 after September. I wonder Until when this stable situation continues. It moves from the root of Pisces to Aries in December and January and is seen high in the south sky at dusk. |
| A lost periodic comet D/1978 C2 (Tritton), which had not recovered in 1984 and 1990, is expected to be brightest now. It is around the forefoot of Leo and high in the south sky at dawn. This comet seems to go both bright and faint rapidly, so the chance to recover it is for a moment. Though it will be at opposition in February, the magnitude will be 18 then. The predicted position is good just on the ecliptic. Will the comet happen to be recovered. |
| A famous periodic comet for its quite small q (0.12 AU), 96P/Machholz 1, is too close to the sun and impossible to see it this month. The condition of this return is worst to see the comet in the Northern Hemishpere and can never observe it. It has been slightly observable in August and September in the Southern Hemisphere. But no observations succeeded. It will keep close to the sun after this and the comet goes faint rapidly. In the Northern Hemisphere it comes to be observable late in next March but the magnitude will be fainter than 20 mag then. Probably no one can see this comet in this return after all. |
| 119P/Parker-Hartley is in its first return now. It had been already observed in last autumn and winter as 16-17 mag. It passed the perihelion on June 24 and was too close to observe it then. Now the comet appears at dawn again. It is in Gemini as 16.5 mag. It is at opposition in January and seen overhead at midnight. Then it faints to 18.5 mag at set in the west in May. |
| 32P/Comas Sola has been much brighter than expected, about 14.5 mag, in early 1996. Then it becomes at conjunction with the sun around the perihelion on Jun. 10. But it has appeared again at dawn last month. It is in Virgo and seen high in the morning sky. The brightness is still about 16 mag. There are 95P/Chiron and 67P/Churyumov-Gerasimenko in the neiborhood. |
| Comet 107P/Wilson-Harrington, which is also registered as an asteroid (4015), passes the perihelion on this Dec. 6. It was observed as 19 mag in May but no following observations was reported. It moves Capricornus -> Aquarius -> Pisces from December to January. It is in the southwest sky at dusk as ever, but the altitude at the end of day light becomes highter, 25 -> 35 deg in December, 35 -> 45 deg in January. It is close to 22P/Kopff, 2P/Encke and P/1996 R2 ( Lagerkvist ) in early January. It passes 5 deg north of Saturn. Because the perihelion distance is 1.00 AU, it can close to the Earth so much and be bright if the comet passes the perihelion in late September. But the condition of this return is bad and reaches 17 mag at most. |
| Comet C/1996 N1 (Brewington), which was discovered on July 4, brightened as 8 mag in August and faded slowly 8.5 -> 10 mag in September. But in mid October it fade away rapidly from 11 mag to 14 mag. Then the comet seemed to be diffused and no following observations succeeded despite the good location. It moves from Pegasus to Andromeda in December and January. It is seen at a good position, almost overhead at dusk, but the predicted magnitude is so faint as 17 -> 19. Because the comet is extremely diffused, it is much harder to observe it. |
| 94P/Russell 4, which will passes the perihelion on Feb. 3, has been observed as 19 mag in November, a bit fainter than expected. It is in Leo in December and Virgo in January as 17-18 mag in the south sky at dawn. It enteres among the galaxies in Virgo. Though this is a small faint comet, the condition is good and reaches 16 mag almost at opposition in next March. Then it is observable until the end of summer when it becomes low in the west as 19 mag. |
| A new periodic comet P/1996 R2 ( Lagerkvist ), which was discovered on Sept. 10 as 17 mag, passes the perihelion on Jan. 20. It has been observed as 16.5 mag recently, which is about 1 mag brighter than at discovery. It moves from Aquarius to Pisces in December and January and seen in the south sky at dusk. It gathers with 22P/Kopff and 46P/Wirtanen near Saturn in early February. Then it becomes too low to observe it. After conjunction with the sun, it becomes to be observable again as 18-19 mag in next summer. |
| A famous periodic comet 2P/Encke will begin to brighten gradually for the perihelion on May 23. It has been already observed as 19-20 mag from July to October. It is in Aquarius to Pisces as 17 mag in December and January. The condition of this return is worst for observers in the Northern Hemisphere. It will be observable until mid February before perihelion , when it is 16 mag, and after perihelion, it reappears in August in Scorpius in the evening southern sky, when the comet is already 12.5 mag. Then it is observable until late November as 19 mag. On the other hand, the condition in the Southern Hemisphere is good. Because the comet closes to the Earth as 0.19 AU on July 5, it becomes much bright in June and July. The comet appears as 7 mag in late June and goes faint 7 -> 10 mag in the high altitude at dusk in July. |
| 100P/Hartley 1, which will pass the perihelion on May 28, has been observable at dawn since mid September and has to be coming brightening now. But no one could observe it yet at this return. It moves from Coma Berenices to Arcturus in December and January. There are many galaxies along the path. It is seen almost overhead in the morning sky and brightens 18 -> 17 mag this month, so it will be observed at first soon. This time the condition is good, almost opposition around the perihelion date, and the magnitude will reach 14 mag in next spring. Then it is observable until it becomes 16 mag in summer. |
| Comet C/1996 E1 ( NEAT ) has been not so clear on its magnitude since the discovery. Anyway on the average, it reached as 11-12 in summer and faded as 13-14 mag in October. After that the comet became so diffused and very hard to observe it. It goes faint as 17 -> 19 mag in Aquarius in the southwest sky at dusk. But it is much harder to observe it than the magnitude shows. In addition the altitude becomes lower rapidly and too low in January. It closes about 1 deg to 43P/Wolf-Harrington on Dec. 6. |
| 43P/Wolf-Harrington, which will pass the perihelion on Sept. 29, 1997, is coming brighter slowly now. It is in Aquarius in December and January and seen in the southwest sky at dusk as 18 mag. The altitude is coming lower and lower, and it becomes too low to observe it in late January. After conjunction with the sun, it appears again at dawn as 13.5 mag in early next summer. Then it reaches 12 mag in autumn and observable with the same brightness for a while. It closes about 1 deg to C/1996 E1 ( NEAT ) on Dec. 6. It passes about 2 deg north of a globular nebula M2(6.5 mag, 13') on Jan. 10. |
| C/1994 J2 ( Takamizawa ), which was discovered in May 1994 and was observed as 9-10 mag in May and June, has been observed for a long time and even now. It was about as bright as 15 mag in autumn in 1995, 16.5 mag in early 1996. Now it is observed as 18 mag. The comet is in the bottom of Orion, almost at opposition and seen in the south sky at midnight. It will be observed as 18-19 mag until next spring. It closes about 10' to Kappa-Ori(2.1 mag) on Dec. 21. In January it moves towards Rigel. |
| A new periodic comet P/1996 A1 ( Jedicke ) discovered in January 1996 as 17 mag has been observed as 16-17 mag until last June. Then it was at conjunction with the sun and it appears again at dawn now. For the recovery in next return, more observations can be a big help. In December and January it is in the south of the head of Virgo and very close to 29P/Schwassmann-Wachmann 1. They closed about 10' each other on Nov. 5 and the distance is still about 1 deg in early December. |
| 67P/Churyumov-Gerasimenko, which passed the perihelion in January 1996 and reached 11 mag then, has been not observable at conjunction with the sun after it faded as 14.5 mag in June. Now it appears again at dawn, just north of Spica. The predicted magnitude is about 18, but not so clear. The altitude will become higher and higher after this. There are 32P/Comas Sola and 95P/Chiron in the neiborhood now. |
| A new asteroid 1996 PW was discovered on Aug. 9 as 18 mag. But the true character is a quite rare object. The orbital elements show that it moves on an orbit with 2.5AU perihelion distance and 3000 year period. That is a typical one of a long periodic comet. But the following observations say that it is quite stella as 17 mag and no sign as a comet has been detected. It has already passed the perihelion on Aug. 8 and it faints 18.5 -> 19 mag this month. It is near Fomalhaut in early December and moves to Beta-Cetus (2.0 mag) and closes it in early February. It is seen in the south or southwest sky at dusk. It will be observable until early February and it will reach 21 mag when it appears again after conjucntion. Then this object goes far away from our solor system and will never be observed again. It was remarkable in comparison with the asteroid-like comet P/1996 N2 (Elst-Pizarro) which was also discovered in this summer. |
| A new asteroid (5145) Pholus, which was discovered on Jan. 9, 1992 as 17 mag, was quite a rare object. The orbital elements show that it moves on an orbit with 8.7AU perihelion distance and 90 year period. Because that is very similar to that of 95P/Chiron, which had been regarded as an asteroid for a long time and the true character is a comet, maybe this object is also a comet. But no coma was detected by the following observations. Though 5 years have already passed since the perihelion date, it can be observed as 18 mag because of the large perihelion distance. No observations are reported after April 1994, but there are some images on films taken in 1997, 14 years before the perihelion, so the object will be observed for a few years after this. It is in Coma Berenices and high in the morning sky this month. The motion is so slight. |
| 74P/Smirnova-Chernykh is now just after the ahelion and in its faintest period as 18 mag. It will brighten slowly until next perihelion in 2001. It is in Aquarius and seen low in the south or southwest sky at dusk now. It set in the west in late January. |
| 129P/Shoemaker-Levy 3 was recovered in October with a predicted magnitude, 19 mag. The perihelion date is Mar. 4, 1998, more than one year ahead, but the orbit is like a circle, the eccentricity is 0.25, and it has already been a CCD target. It is in Pisces in December and January and seen high in the evening sky. It passes about 40' south of a galaxy M74(9.1 mag, 10') on Feb. 2. This comet is a small one and reaches only 17 mag around the perihelion. |
| A new periodic comet P/1996 N2 ( Elst-Pizarro ), discovered on July 14 as 18 mag, is a remarkable object. The orbital elements show that it moves on a typical asteroid orbit. It has already faded away so much and the current image shows only the tail with no nucleus. Maybe the comet has bursted a bit temporarily and the tail extended and then discovered. It is in Aquarius now and seen in the southwest sky at dusk. It will set in the west in February. It was remarkable in comparison with the comet-like asteroid 1996 PW which was also discovered in this summer. |
| 111P/Helin-Roman-Crockett has just passed the perihelion on Oct. 31. But the eccentricity is 0.14, like a circle, so the magnitude will change slightly. It has been observed as 21 mag since 1995, which is so faint. It is in the south of Pollux in Gemini now. It is at opposition in January and locates overhead at midnight. |
| 120P/Mueller 1 is now at opposition. The condition of this return is worst, at conjunction around the perihelion in last April. So it brightens at most at opposition both half a year before and after the perihelion. So now it is brightest but the magnitude is extremely faint, fainter than 20 mag. It is in Auriga and almost overhead. |
| 127P/Holt-Olmstead is also just after opposition now. It has been brightest this autumn but the magnitude was so faint as 21 mag. The perihelion date is next February, but it goes fainter after this. It is in Aquarius and so low in the southwest sky at dusk. |
Ephemeris Table
m1 = -0.4 + 5 log d + 8.0 log r
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m1 = 6.5 + 5 log d + 10.0 log r
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m1 = 10.5 + 5 log d + 10.0 log r
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m1 = 5.2 + 5 log d + 21.5 log r
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m1 = 1.4 + 5 log d + 27.0 log r
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m1 = 8.5 + 5 log d + 15.0 log r
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m1 = 6.7 + 5 log d + 21.0 log r
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m1 = 5.3 + 5 log d + 21.0 log r
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m1 = 6.5 + 5 log d + 20.0 log r
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m1 = 4.0 + 5 log d + 7.5 log r
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m1 = 7.7 + 5 log d + 10.0 log r
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m1 = 6.5 + 5 log d + 10.0 log r
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m1 = 11.5 + 5 log d + 15.0 log r
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m1 = 12.0 + 5 log d + 10.0 log r
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m1 = 6.2 + 5 log d + 20.0 log r
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m1 = 7.0 + 5 log d + 15.0 log r
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m1 = 2.0 + 5 log d + 18.0 log r
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m1 = 4.0 + 5 log d + 7.5 log r
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m1 = 10.0 + 5 log d + 10.0 log r
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m1 = 13.0 + 5 log d + 20.0 log r
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m1 = 13.0 + 5 log d + 12.0 log r
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m1 = 2.0 + 5 log d + 25.0 log r
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m1 = 5.5 + 5 log d + 22.5 log r
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m1 = 16.5 + 5 log d + 5.0 log r
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m1 = 10.8 + 5 log d + 15.0 log r
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m1 = 10.5 + 5 log d + 15.0 log r
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m1 = 9.0 + 5 log d + 15.0 log r
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m1 = 11.0 + 5 log d + 12.0 log r
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m1 = 9.0 + 5 log d + 20.0 log r
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m1 = 7.4 + 5 log d + 23.0 log r
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m1 = 8.0 + 5 log d + 15.0 log r
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m1 = 4.2 + 5 log d + 10.0 log r
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m1 = 3.0 + 5 log d + 17.0 log r
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m1 = 9.3 + 5 log d + 11.5 log r
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m1 = 14.0 + 5 log d + 5.0 log r
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m1 = 8.0 + 5 log d + 5.0 log r
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m1 = 8.5 + 5 log d + 10.0 log r
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m1 = 11.0 + 5 log d + 10.0 log r
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m1 = 13.5 + 5 log d + 7.5 log r
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m1 = 7.0 + 5 log d + 20.0 log r
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m1 = 14.0 + 5 log d + 10.0 log r
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m1 = 14.0 + 5 log d + 15.0 log r
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Finding Charts (PostScript)
These finding charts are made with
StellaNavigator Ver.2.0 for Windows (AstroArts / ASCII)
.