|
Japanese version Home page |
Updated on August 1 1996 |
|
Back to last version. Go to next version. | |
|
Here is the ranking of comets in August, 1996.
Comet C/1995 O1 (Hale-Bopp), the probable greatest comet in this century, is really coming bright now. The magnitude is already 5.5-6.0 now, which means a naked-eye object. This comet is the hottest topic in this summer. New comet C/1996 N1 (Brewington) discovered on July 4 is 9-10 mag in the evening sky. A periodic comet 22P/Kopff passes the perihelion last month and is about 9 mag. 57P/du Toit-Neujmin-Delporte, which is normally 18 mag or fainter, bursted to be 13 mag. This comet is usually too faint to observe but now is a big chance to see it. In addition, someone report that comet C/1996 E1 (NEAT), which has been expected to be about 15 mag, bursted suddenly and is 10-11 mag now. But many people says that they cannot see it. Maybe it is too low in the northern sky. Anyway the brightness of this comet is indistinct. The super comet C/1996 B2 (Hyakutake), which passed 0.10 AU far from the earth and reached 0 mag with 100 deg tail late in March, left to the southern sky. It passed the perihelion on May 1 and is getting fainter slowly day by day. It is about 8 mag now.
Other faint comets are as follows.
|
Comet C/1995 O1 (Hale-Bopp), which was discovered a year ago (July
1995) with 11 mag and said to be extremely bright in next spring, is
really coming bright now. It was about 10 mag just before set in the
west last autumn. After conjunction with Sun it appeared in the east
again at dawn in late February with magnitude 8-9. It has been coming
brighter favorably, 7-8 mag in May, 6 mag in June, 5.5-6.0 mag in
July and already been a naked-eye object. The diameter is already 15',
half of the Moon. You can see the comet even through 5cm finding
scope. This is a big present for our summer vacation.
|
| Date | Time | Comet mag. | Star | Star mag. |
| Jul. 30 | 20:30 | 5.8 mag | PPM201505 | 9.5 mag |
| Sep. 4 | 21:51 | 5.3 mag | PPM200854 | 9.8 mag |
The comet moves west until late September, then starts to move to the northeast in Ophiuchus after October. But because the speed is not fast now, it will be in Ophiuchus until its set in the west in early December. The magnitude reaches 4 mag if it goes along expectation. On the way it closes a globular cluster M14 (7.5 mag, 12') in Ophiuchus from mid October to late October. The hilight is October 27 and the distance is about 20'. The magnitude of the comet is about 4-5.
It is not observable from late December to early January. After that it appears at dawn in mid January and seen in the dawn sky till mid March. In this period the magnitude brightens rapidly from 2 mag to -1 mag. March 9 is the day of a solar eclipse in Mongolia and Siberia and the comet is seen overhead just in the eclipse. The "eclipse comet" is after an interval of 115 years. The comet outruns the Sun around March 20. But Hale-Bopp can be watched even both in the evening and at dawn these days because it passes 45 degress north of the Sun at this conjunction and the brightness is at peak, -1 mag. It is seen in the evening sky from late March to late May and the magnitudes goes down from -2 to 1. It begins to move south these days. After set in the west in late May with magnitude 1, we cannot see the comet for a while. In autumn it appears just over the horizon in the south east with magnitude 5 from September to October. But it leaves to the south in November and then will never seen again in the Northern Hemisphere.
C/1996 B2 (Hyakutake), discovered in the morning on January 31 by Yuji
Hyakutake in Japan, became one of the greatest comets since comet West
in 1976. The comet closes 0.10 AU to the earth on March 25 and then it
was 0 mag with 100 deg long tail. On the contrary it shined overhead at
midnight so we could watch it all night. We could see it move among
stars with a telescope.
|
22P/Kopff has passed the perihelion on July 2 and observed as 8-9 mag
last month. It became much larger in July, as 5-10' diameter. Perhaps
it is because the comet is at perihelion. It goes far away from both
the sun and the earth after this and faints day by day.
|
On July 4 Mr. Howard Brewington in New Mexico discovered a new comet
C/1996 N1 (Brewington) in the evening sky with magnitude 10.
This comet passes the perihelion on this August 3, and is brightest
now.
|
Returning periodic comet P/1983 M1 (IRAS) is expedted to see with
magnitude 11 from autumn to winter but not yet detected in late
July. Now the comet is not observable in the Northern Hemisphere but
the condition in the Southern Hemisphere is so good and probably 12.5
-> 11.5 mag this month. It will be detected soon.
|
A periodic comet 116P/Wild 4 has been as bright as 12 mag in this
spring and passes its perihelion on August 31. But the condition of
this return is bad and cannot be observed because it is too close to
the sun this month.
|
C/1996 E1 (NEAT) is a new comet discovered on March 15. Some people
reports that this comet bursted and is 10 mag now, so it is noteworthy
now. This is very low in the northern sky now but rises higher and
higher after this. Please confirm the image of this comet.
|
C/1996 J1 (Evans-Drinkwater) is a new comet discovered on May 16 with
magnitude about 16. The reported magnitude is 16 and very faint but
actually it seems to be about 14 mag now. The perihelion is January 2,
1997, much in advance, and the distance is 1.2 AU. It brightenes
slowly after this and reaches 9-10 mag around its perihelion.
|
65P/Gunn has already passed the perihelion on 24 July. This comet has
been observed as 12-13 mag for these several months. It will be
gradually faint after this.
|
| Date | Period | Comet mag. | Object | Kind | Mag | Diameter | Distance |
| Aug. 16 | - 17 | 13 mag | M4 | globular cluster | 5.9 mag | 26' | passes in front |
| Aug. 16 | 12 days | 13 mag | M4 | globular cluster | 5.9 mag | 26' | in 1 deg |
| Aug. 20 | 12 days | 13 mag | Antares | 1.0 mag | in 1 deg | ||
| Sept. 17 | 4 days | 13.5 mag | M62 | globular cluster | 6.5 mag | 14' | in 2 degs |
| Sept. 17 | 4 days | 13.5 mag | M19 | globular cluster | 7.1 mag | 14' | in 3 degs |
| Sept. 25 | 13.5 mag | NGC6304 | globular cluster | 8.3 mag | 7' | 40' | |
| Sept. 26 | 13.5 mag | NGC6316 | globular cluster | 9.0 mag | 5' | 1.5 deg |
But the comet is so low in the west and so faint that it is hard to enjoy these phenomena.
A Periodic comet 57P/du Toit-Neujmin-Delporte passed the perihelion in
last spring, March 5, has made a super outburst and brightened 6 mag
and is now 13 mag at dawn.
|
32P/Comas Sola has already passed its perihelion on June 10 and
is at conjunction and not observable now. Even the condition of this
return is bad, it was observed brighter than expected. About 15 mag in
this year. The magnitude equation from last August (20 mag) is
|
22P/Schwassmann-Wachmann 1 bursted out in last February and reached
about 11 mag. But after that it extremely diffused and has beed quite
hard to observe. The diameter was about 4-5' in March and April but is
less than 1' now. The reported magnitudes were decreasing since May
and about 14 mag in mid June.
|
A famous periodic comet for its quite small q (0.12 AU), 96P/Machholz 1,
which passes the perihelion on October 15, will begin to be bright
rapidly now. It is in the southern sky and not yet observed in this
return. But the magnitude brightens from 16.5 to 14.5 in August, from
14.5 to 9 in September and so the observations will be reported
soon. By the way this comet cannot be observed in the Northern
Hemisphere in this return at all.
|
125P/Spacewatch was detected in March with magnitude 17 and kept 17
mag after that. But it was observed brighter in July, 15.5 mag in
early July and 14.5 mag in late July. It passed the perihelion on July
14 and seems to become fainter after this. It is about 15 mag this
month.
|
| 95P/Chiron, originally considered as an asteroid and registered again as a comet, is still west of Spica this month and too low in the west to observe it. The height just after daylight is only about 10 degrees even in early August. It is under the horizon in late August. The comet will be observable again in December. It passed its first perihelion in last February but the distance from the Sun is 8.5 AU and no happenings on it. It has been stellar with magnitude 15. The observation of it finish this month but CCD users can observe it for some years after this because of the large q and its slow magnitude curve like an asteroid. Generally about 16 mag in 2000, 17 mag in 2002 and 18 mag in 2004. |
| P/1987 U1 (Shoemaker-Holt 1), which passes the perihelion in November 1997, has not been detected yet. It is in the northeast of Aquarius and should be about 16.5 mag in August and September. It is at opposition in next month. But those who tried to detect it in July could not get the image. So probably the comet is much fainter. Anyway because the condition is best now, it is a good target for CCD users. This season is pre-perihelion and expected to be 16.5 mag in summer and autumn. It sets in the west in next February with magnitude 17 and appears again in July with magnitude 16. Then it reaches 15 mag in November at opposition. It will be observable for a few years after that. |
| 119P/Parker-Hartley is in its first return now. It passed the perihelion on June 24 and was too close to observe it then. Now the comet appears at dawn again. Before the perihelion it was observed from last summmer to last winter with magnitude from 19 to 16. It will go away from the sun after this but the distance changes so slightly that it will be observable as 16-17 mag until the opposition in January. Then it faints to 18.5 mag at set in the west in May. It is now in Gemini in August and September and moves together with 81P/Wild 2 within 3 degrees. Especially those two comets and Venus and M1(nebula, 8.3 mag, 6') are all within 5 degrees. |
| 118PShoemaker-Levy 4, which is also in its first return now, appeared at dawn again. It was observed as 22 -> 20 mag from last summer to autumn and brightened as 17 mag in last July. It is brighter than expected. The comet is in Taurus in August and Orion in September. The magnitude is 17.5 -> 16.5 then. The perihelion is in next January and it is just at opposition. So the condition of this return is best and brightens as 14.5 mag in winter. Then it will be observable until setting in the west in June as 18 mag. |
| 117P/Helin-Roman-Alu 1 has been observed as 17 mag since detected in May 1995. But it is in the head of Scorpius and will be low in the west this month and maybe unable to observe it. The perihelion is March 1997 and the distance is 3.7 AU so the comet becomes observable with 17 mag in next May. |
|
C/1995 Y1 (Hyakutake) was discovered at dawn
on December 26 and brightened as 8 mag in February and March. Then it
came faint and 11 mag in April. But it suddenly darken after that and
reached 16 mag late in May. It was observed as 17-18 mag in
July. Comparing the two magnitude equations, before darkening and
after darkening,
|
| A periodic comet P/1990 R2 (Holt-Olmstead) will pass its perihelion in next February as its first return. It is at opposition in August and September. It has been low in the south and not detected yet but it should be 17.5 mag now. But those who tried to detect it in July could not get the image. Maybe it is much fainter. The condition of this return is not good and hard to see at its perihelion because it is close to the sun. The magnitude is only 18.5 at that time. About one mag brighter in this autumn than at perihelion and the position is better, just after opposition, therefore this summer and autumn is best to observe it. It is one of good targets for CCD users. |
| 46P/Wirtanen passes its perihelion in next March and was expected to be 10 mag then. But it was observed in July as 19 mag, 1 mag fainter than expected. It is at opposition in Piscis Austrinus in August, and enters into Microscopium in September. It is low in the south and will be an evening low-sky object soon. But it keeps the same position, 25 deg high in the evening, from December to next July. The comet will brighten as 12 mag in March and faint to 16 mag in July. By the way comet P/1990 R2 (Holt-Olmstead) is also in Piscis Austrinus with magnitude 18. |
| Comet 85P/Boethin, which will pass the perihelion in next April, has not been observed in this return yet. It is in the Milky Way in the northwest of Sagittarius in August and September and be close to open clusters M6(4.1 mag, 15') and M7(3.2 mag, 80'). It is already in the south in the evening and will be low in the west in September, become unable to observe in October. The condition of this return is worst. It should be 9.5 mag around the perihelion but too close to the sun to see it. After setting in October, it will appear at dawn about one year later, October 1997. Then it is as faint as 17 mag. |
| 81P/Wild 2, which will pass the perihelion in May 1997, appears again at dawn. It was about 20.5 mag in last January and is now 18 mag in Gemini. It moves along a periodic comet 119P/Parker-Hartley. Comet 81P/Wild 2 will be observable as 12-13 mag in the evening sky from January to July in 1997. So it can be observed for about a year after now including the day of perihelion. |
| A lost periodic comet D/1978 X2 (Tritton) is expected to begin to brighten now. It is in the dawn sky and moves from Taurus to Auriga in August and enters into Gemini in September. The expected magnitude is 19 > 18. The perihelion is in November, and from then to January, when the comet approaches the earth, it is obvserable as 16-17 mag. Then it faints rapidly after the opposition and reaches 20 mag in April. The condition of this return is not bad. Will this comet be really detected. |
| Comet 77P/Longmore has already passed ths perihelion in last October and goes fainter and fainter. It has been already observed as 16-17 mag in spring 1995. It is now in Microscopium and unable to observe in Japan. It maybe cannot be observed even in the Southern Hemisphere because it is as faint as 19 mag. |
| Comet 107P/Wilson-Harrington, which is also registered as an asteroid, will pass the perihelion on December 6. It was observed as 19 mag in May. It is in Libra in August and Scorpius in September. It is quite a evening low-sky object now. It is hard to observe it from September to November because the height is less than 20 degrees just after daylight. Then it moves higher again and keeps high enough until next March. The magnitude of this period is about 17. Then the comet becomes low and faint rapidly and sets in the west in late May as 20 mag. |
| 43P/Wolf-Harrington, which will pass the perihelion in September 1997, is now at opposition in Aquila and seen overhead as 18.5 mag. Nobody has observed this comet yet. It brightens as 17.5 mag in January and sets in the west. After conjunction, it appears again at dawn near by the Pleiades as 14.5 mag. Then is will be seen as 12 mag from September to January 1998. Moreover it will be observed until set in June 1998 as 17 mag, totally for more than one year. |
| P/1990 R1 (Mueller 2) is also waiting for being detected. It is in Scutum as 19 mag now. It will be observable until late November. The perihelion is in November 1997 and seems to brighten as 15.5-16 mag then. After conjunction it will appears again at dawn as 17.5-18 mag in next May. By the way this comet has not been detected at opposition in this early summer so maybe it is actually much fainter. |
| Comet 73P/Schwassmann-Wachmann 3, which bursted and brightened as 6 mag in autumn 1995, is now seen high at dawn,. It is just in Hyades. The burst has been already finished and the comet should be extremely faint now. It was about 14 mag in February so is expected to be 19 mag in August. But it should be much fainter actually. |
| A famous periodic comet 2P/Encke will begin to brighten gradually for the perihelion in next May. It is 19 mag in Pisces in August and September. Saturn is just south of the comet. It is at opposition next month and observable until set in the west as 16 mag in next February. It is too close to the sun around the day of perihelion and moves southwards rapidly after perihelion. So the condition of this return is good for southern observers, bad for northern observers. After perihelion it appears as 7 mag in June in the Southern Hemisphere and will be observed until autumn. Then the comet is about 18 mag. Northern observers can see it after mid August 1997 but the comet is fainter than 13 mag. |
| 7P/Pons-Winnecke is now in its 21th return. But it has been close to the sun and unable to see at all. It finally came away from the sun but was observed as faint as 19 mag in July. It is in Eridanus in August and September but observing it is so hard. By the way, in early August it is close to the supernova SN1996an in NGC1084 discovered by Mr. Aoki on July 27 as 14 mag. |
| A lost comet 72P/Denning-Fujikawa should have passed its perihelion on May 29 and seems to leave without being observed in this return as well. The extremely rapid magnitude change is a big characteristic of this comet and it is bright enough to be observed only around the perihelion. This time observers in the Southern Hemisphere had a little chance to detect it in this spring but not seen after all. It moves from Gemini to Cancer in August but is too close to the sun to see. In the Northern Hemisphere it appears at dawn in Leo in September but the magnitude is 24 or fainter, too dark to see. |
m1 = -2.0 + 5 log d + 10.0 log r
|
m1 = 4.9 + 5 log d + 7.0 log r
|
m1 = 5.3 + 5 log d + 21.0 log r
|
m1 = 9.8 + 5 log d + 15.0 log r
|
m1 = 6.0 + 5 log d + 20.0 log r
|
m1 = 1.4 + 5 log d + 27.0 log r
|
m1 = 8.0 + 5 log d + 20.0 log r
|
m1 = 6.5 + 5 log d + 10.0 log r
|
m1 = 7.7 + 5 log d + 10.0 log r
|
m1 = 6.5 + 5 log d + 15.0 log r
|
m1 = 5.5 + 5 log d + 22.5 log r
|
m1 = 4.0 + 5 log d + 7.5 log r
|
m1 = 13.0 + 5 log d + 12.0 log r
|
m1 = 10.5 + 5 log d + 20.0 log r
|
m1 = 4.0 + 5 log d + 7.5 log r
|
m1 = 8.5 + 5 log d + 10.0 log r
|
m1 = 2.0 + 5 log d + 25.0 log r
|
m1 = 10.0 + 5 log d + 15.0 log r
|
m1 = 6.0 + 5 log d + 15.0 log r
|
m1 = 10.0 + 5 log d + 14.5 log r
|
m1 = 11.0 + 5 log d + 15.0 log r
|
m1 = 11.0 + 5 log d + 15.0 log r
|
m1 = 6.5 + 5 log d + 20.0 log r
|
m1 = 9.0 + 5 log d + 15.0 log r
|
m1 = 13.0 + 5 log d + 20.0 log r
|
m1 = 7.0 + 5 log d + 20.0 log r
|
m1 = 16.5 + 5 log d + 5.0 log r
|
m1 = 8.0 + 5 log d + 15.0 log r
|
m1 = 11.0 + 5 log d + 10.0 log r
|
m1 = 5.5 + 5 log d + 20.0 log r
|
m1 = 11.0 + 5 log d + 12.0 log r
|
m1 = 11.0 + 5 log d + 15.0 log r
|
m1 = 15.5 + 5 log d + 25.0 log r
|