Updated 2001 February 5
SOHO 74 (1999 O1) and SOHO-76 (1999 P3). D. A. Biesecker, SM&A Corporation and Goddard Space Flight Center, repored measurements of two apparent Kreutz sungrazing comets (both tailless) discovered with the LASCO C3 coronagraph aboard SOHO on 1999 July 31.51 and August 3.24 [IAUC 7367, 2000 February 15]. 1999 O1 was found by T. Lovejoy in movies posted at the SOHO website. 1999 P3 was found by D. Lewis.
I discovered SOHO-97=2000 B1 on January 24. I had to leave work early on January 24 in order to pick up my car which had been in for servicing (an expensive business as several repairs were needed) and went straight home afterwards as it was clear and I wanted to grab a bite to eat before it got dark. I then cycled out to the Cambridge Observatories and got out the great Northumberland refractor at around 17:50. I observed 141P/Machholz 2 (a bit iffy at 13m), 114P/Wiseman-Skiff (glimpsed with averted vision at 14m) and 1999 S4 (LINEAR) (not seen and [13.8). I could see clearly several galaxies catalogued at 13m. I also observed a few binocular variables and then thought about going bell-ringing (one of my other hobbies) at 19:30 as the practice started at 19:00 and I would be late. However, I decided to have a quick look at the SOHO images first on the IOA Starlink system. As soon as the java loop had downloaded it was obvious that a Kreutz fragment was heading in towards the sun. I immediately emailed Doug and Brian Marsden, though this one was so obvious that I was sure there would have been prior claims. It turned out that there weren't and Doug posted the discovery on his web page and quickly got the positions for Brian to compute the orbit, which appeared on IAUC 7349 at 23:10. The comet peaked in brightness at around 5th magnitude on the morning of January 25, and began to grow a tail, but also to fade. It disappeared from the C3 frames but a ghostly image was visible for a couple of hours on the C2 frames between 16:06 and 18:30.
Faint Kreutz fragment SOHO-98 (2000 B6) was discovered by Maik Meyer on January 29, however an independent discovery was made by Michael Oates of the SPA on January 30. He had heard a talk that I gave on January 29 about my discovery of SOHO-97 and decided to try it himself. He wasn't aware of the real time movie loops and so downloaded individual high resolution frames and made a movie himself. Looking at the sequence he spotted the moving image of the Kreutz fragment, however he was beaten to it by Maik Meyer. He has posted some images of the comet on the SPA web page.
SOHO-99 (2000 B7) was also discovered by Maik Meyer, and almost simulataneously by Terry Lovejoy. Maik has provided an account of the discovery of his two comets.
Three more comets, including SOHO-100 were discovered between February 3 and 5 on LASCO C2 frames, moving in similar trajectories diagonally across the upper left quadrant. There seems to be a swarm of these objects, with a fourth discovered by Michael Oates and visible on the C2 images from 18:54 - 20:44 on February 7.
SOHO-104 (2000 C6) was a Kreutz fragment discovered by Terry Lovejoy on February 9.
SOHO-106 (2000 D1) D. A. Biesecker, SM&A Corporation and Goddard Space Flight Center, reports observations of an evident Kreutz sungrazing comet with a tail discovered by D. Lewis in SOHO/LASCO C3 data on February 28.57. Biesecker provides apparent magnitudes brightening from V = 7.4 +/- 0.2 on Feb. 28.971 to 5.8 +/- 0.1 on Feb. 29.404 UT. [IAUC 7370, 2000 February 29]
SOHO-107 (2000 E1) D. A. Biesecker, SM&A Corporation and Goddard Space Flight Center, reports that several people browsing the SOHO Web site (including M. Meyer, M. Boschat, T. Harincar, and M. Oates) noted another Kreutz sungrazing comet in SOHO LASCO data on March 4.40. Observed in both the C2 and C3 telescope data, this object showed a tail of length about 10'. [IAUC 7376, 2000 March 7]
On the same IAUC Biesecker also reports observations (measures by D. Hammer and himself, reductions by B. G. Marsden) of some older Kreutz sungrazing comets seen in SOHO C3 data; full astrometry and parabolic orbital elements appear on the MPECs indicated below. Comet C/1999 O2 developed a short tail, C/1999 O3 had a short tail evident, C/1999 Q3 showed a tail, and C/1999 R3 showed evidence for a tail; the other four comets showed no evident tail. Comets C/1999 O2 and C/1999 P4 were discovered by D. Lewis, C/1999 P5 by A. Vourlidas, C/1999 Q2 and C/1999 R3 by K. Schenk, and C/1999 Q3 by Biesecker, while comets C/1999 O3 and C/1999 Q1 were first noted by T. Lovejoy via the SOHO Web page.
SOHO-108 (1999 E2) D. A. Biesecker, SM&A Corporation and Goddard Space Flight Center, reports that M. Oates, Manchester, England, found another Kreutz sungrazing comet in archival SOHO LASCO C3 Web data from 1999 March 2.51. [IAUC 7377, 2000 March 9]
On IAUC 7383 [2000 March 17], D. A. Biesecker reported observations (measures by D. Hammer and himself, reductions by B. G. Marsden) of four more tailless, Kreutz sungrazing comets seen in SOHO C3 data, during 1999 September, which were discovered by K. Schenk, except for C/1999 R4, which was first noted by T. Lovejoy via the SOHO Web page.
1999 J6 SOHO (IAUC 7386, 2000 March 24) On IAUC 7386 [2000 March 24] D. A. Biesecker reported observations (measures by D. Hammer and himself, reductions by B. G. Marsden) of four more comets seen in 1999 SOHO data, all but C/1999 J6 being presumed Kreutz sungrazers. Comets C/1999 J6 (visible in both C2 and C3 data) and C/1999 U5 (visible in only the C3 telescope) show no tail. However, C/1999 W1 and C/1999 Y3, which were both visible with only the C2 telescope, did show tails. Selected V magnitudes from Biesecker for C/1999 J6: May 10.750 UT, 8.1; 10.833, 7.3; 10.935, 6.5; 11.088, 5.9; 11.269, 5.5, 11.338, 4.9; 11.462, 5.1. Comet C/1999 J6 was first noted by M. Oates in archival data via the SOHO Web page on ? 2000 March 20; C/1999 U5 and C/1999 W1 were discovered by Biesecker, and C/1999 Y3 was discovered by A. Vourlidas of the SOHO team.
On the same IAUC Doug Biesecker also reported observations of four additional Kreutz sungrazing comets detected by SOHO in the first few months of 2000. Comet C/2000 B5 (SOHO-96) was discovered by Biesecker on January 18; the other three comets were found by several people browsing the SOHO web site, as follows: C/2000 B6 (SOHO-98), M. Meyer, T. Lovejoy, J. Shanklin, and M. Oates; C/2000 B7 (SOHO-99), Meyer and Lovejoy; C/2000 D3 (SOHO-105), Meyer and K. Cernis. C/2000 D3 was visible with both the C2 and C3 telescopes and showed a short tail; the other three comets showed no apparent tail and were visible only in the C3 data.
I discovered SOHO-110 (2000 F1) from the IOA in Cambridge, whilst updating these web pages! I'd looked at the C3 images and had set the C2 movie to download. Whilst it was doing this I started editing the main index and then spotted what might be a Kreutz fragment on the loop which had started to run in the background. I emailed the observing group (sorry about the wrong subject header) and almost immediately got a message back from Maik Meyer saying that he had also spotted the object. It was visible from 04:30 to 07:31 and my discovery was made at 09:09.
SOHO-111 (2000 H2) The brightest Kreutz sungrazer for some time was discovered on April 28.51 by Terry Lovejoy, Mike Boschat, Michael Oates and R Gorelli on images from the SOHO website. The comet was observed in both the C2 and C3 SOHO telescopes, and a tail at least 0.5 deg long was visible. The comet evidently became brighter than mag 1, but at peak brightness, the coma saturated the CCD detector.
Doug Biesecker found SOHO-113 on May 09 whilst testing his automated search routine in situations where the satellite was rolled. This object was found in data from 1999 February 6.10, about 24 hours in front of SOHO-58.
SOHO-114 was discovered by Kazimieras Cernis on May 09.73, about 5' east of Saturn on C3 frames. It appeared on C2 frames between 01:26 and 05:26 on May 10. This is the 100th Kreutz fragment found by SOHO. The IUAC quotes: D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports observations of two more Kreutz sungrazing comets found in SOHO LASCO C3 data. C/1999 C2 was found by Biesecker, and no tail is evident. C/2000 J3 was found by K. Cernis and M. Boschat via the SOHO website; it is also visible in C2 data, where a tail is evident, and Cernis estimates m_1 about 7 on May 9.9 UT. [IAUC 7422, 2000 May 11]
SOHO-115 was discovered by Michael Oates on May 15 at 06:25 UT on C2 frames between 02:06 and 06:26 and is fairly easy to see moving towards the Sun from the bottom of the frame. The comet was also discovered by Xavier Leprette at around the same time. The IAUC quotes: D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports observations of another Kreutz sungrazing comet found by M. Oates and X. Leprette in LASCO C2 data beginning on May 14.90 at the SOHO website. The comet is also visible in C3 data, and a very short tail is visible. [IAUC 7426, 2000 May 19]
2000 K3 SOHO SOHO-116 (2000 K3) was discovered by Mike Boschat on May 20 on C2 frames beginning at May 19.89. Michael Oates made an independent discovery, but it had already been announced on the web.
2000 J5 SOHO SOHO-117 (2000 J5) was discovered by Michael Oates on May 21 in C2 archival data from May 11.81. This data was not down loaded in real time and hence the comet escaped detection.
2000 K4 SOHO SOHO-118 (2000 K4) was discovered by Michael Oates in real time C2 data on May 22 beginning at May 22.58. Xavier Leprette made an independent discovery, although it had already been announced on the web.
2000 K5 SOHO SOHO-119 (2000 K5) was discovered by Michael Boschat and Michael Oates on C2 data from May 25 beginning at May 25.98.
The discoveries were announced on IAUC 7433 [2000 May 30]: D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports observations of four additional Kreutz sungrazing comets detected by SOHO with the LASCO C2 telescope. The comets were found via the SOHO website by M. Oates (C/2000 J5, C/2000 K4, C/2000 K5) and by M. Boschat (C/2000 K3, C/2000 K5). All but C/2000 K5 showed a tail, those of C/2000 K3 and C/2000 K4 being noted as short.
2000 K6 SOHO SOHO-120 (2000 K6) was discovered by Michael Oates, Xavier Leprette and Mike Boschat in C2 data on May 27.
1998 V1 SOHO SOHO-121 (1998 V1) was discovered by D Hammer using the automated search routine on data from 1998 November 4 in C2 and C3 data.
The discovery announcement appeared on IAUC 7435 [2000 June 2] D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports SOHO observations, beginning on 1998 November 4.15 of another Kreutz sungrazing comet discovered by D. Hammer and Biesecker using the automated search algorithm developed by Biesecker. The comet, which showed a tail, was seen in both the C2 and C3 telescopes. Biesecker also reports observations of another Kreutz sungrazing comet found via the SOHO website by M. Oates, X. Leprette, and M. Boschat. The comet, which showed no tail, was visible in the C2 telescope only from May 27.09.
SOHO-122 was discovered by Michael Oates on 2000 June 6 in archival C2 images from 1999 May 7. It follows a nearly parallel path to SOHO-62, but is a few hours earlier. That evening he checked further images from May 1999 and found a further four comets! Not content with that he then checked a missing block of data from June 2000 and found another one. This is an all time record for cometary discoveries in 24 hours. Congratulations to Michael. Michael has a web page showing his discovies.
Another batch of archival SOHO finds was made the weekend of June 9 - 10 with Michael spotting another five. There were also two real time finds.
These were announced on IAUC 7439 [2000 June 14]: D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports observations of thirteen additional Kreutz sungrazing comets detected by SOHO with the C2 telescope, with measurements by D. Hammer and Biesecker (the reductions and orbital elements by B. G. Marsden appearing on the MPECs specified below). None of the objects showed a tail. All of the comets were found via the SOHO website by M. Oates except for C/2000 L2, which was found by M. Boschat; Boschat and X. Leprette also found C/2000 L3.
1999 UT R.A. (2000) Decl. MPEC Comet
May 5.326 2 52.3 +14 53 2000-L46 C/1999 J7
7.726 3 01.0 +15 29 2000-L47 C/1999 J8
9.226 3 06.6 +15 54 2000-L48 C/1999 J9
10.976 3 12.9 +16 17 2000-L49 C/1999 J10
14.504 3 26.6 +17 09 2000-L50 C/1999 J11
19.960 3 46.9 +18 29 2000-L51 C/1999 K11
23.563 3 59.9 +18 54 2000-L52 C/1999 K12
24.327 4 01.4 +18 53 2000-L53 C/1999 K13
27.976 4 17.6 +19 41 2000-L54 C/1999 K14
28.810 4 21.3 +19 49 2000-L55 C/1999 K15
2000 UT R.A. (2000) Decl. MPEC Comet
June 3.479 4 46.7 +20 41 2000-L56 C/2000 L1
9.813 5 10.9 +21 10 2000-L57 C/2000 L2
10.165 5 12.8 +21 17 2000-L58 C/2000 L3
On June 14 SOHO-135 was discovered on C2 by Michael Boschat, Maik Meyer and Xavier Leprette. I had looked a few minutes earlier, but failed to spot the comet. Michael Oates discovered another two archival SOHO comets from May 1998 on June 15 (SOHO-136 and 137).
For me success came again on June 15. I had been into Cambridge to set up a display for the Cambridge Natural History Society Conversazione (an annual exhibition) and had then gone home to mend a puncture. On returning to work I started to download the latest real-time movie sequence, but then had to extract some images of meteorological equipment for a colleague. On returning to the movie I initially didn't spot anything, but then saw the Kreutz group object moving towards the sun from the bottom right hand corner of the image. I quickly sent out a message and at almost the same time got a message from Michael Boschat saying that he had also found it. Michael Oates sent a message saying that he was just downloading the images and we had beaten him to it. I then measured the positions and sent them off to Doug. (SOHO-138)
Nine comets were designated on IAUC 7445 [2000 June 29] : D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports observations of nine additional Kreutz sungrazing comets detected by SOHO with the C2 coronagraph, with measurements by D. Hammer (the reductions and orbital elements by B. G. Marsden appearing on the MPECs specified below). Comets C/1998 J3 and C/1998 J4 were discovered by Hammer in a search of archival data. The remaining comets were found via the SOHO website by M. Oates (C/1998 K12, C/1998 K13, C/1998 K14, C/1998 K15); M. Boschat (C/2000 L4, C/2000 L5, C/2000 M1); M. Meyer and X. Leprette (C/2000 L4); J. Shanklin (C/2000 L5); and P. Shrekby (C/2000 M1).
1998 UT R.A. (2000) Decl. MPEC Comet
May 4.666 2 50.3& +14 43 2000-M27 C/1998 J3
6.227 2 56.3& +15 09 2000-M28 C/1998 J4
20.967 3 51.6& +18 34 2000-M29 C/1998 K12
21.769 3 51.9& +18 30 2000-M30 C/1998 K13
26.424 4 12.7& +19 31 2000-M31 C/1998 K14
28.584 4 19.7& +19 46 2000-M32 C/1998 K15
2000 UT R.A. (2000) Decl. MPEC Comet
June 14.576 5 29.0& +21 32 2000-M33 C/2000 L4
15.576 5 32.0& +21 41 2000-M34 C/2000 L5
17.757 5 42.1& +21 34 2000-M35 C/2000 M1
I only just missed 142 as I'd looked around that time but hadn't noticed the object.
June 19/20 was another busy day for Michael Oates, setting a new record of seven comets in 24 hours.
I made an independent discovery of SOHO-169 in the closing moments of the 2nd test against the West Indies. I downloaded the C2 loop and in the interval between overs had a quick look and spotted a Kreutz comet moving into the frame on images from 16:00 onwards. I mailed Doug at 17:50 and in the meantime England inched towards victory. I downloaded the C3 and spotted a comet moving in towards the sun since 08:42 and deduced that it was probably the same one and had already been discovered. England won and I sent another message to Doug and then lightning struck the local area and there was a power glitch and everything went down. I restarted the PC and then checked Doug and Maik's page to find that SOHO-169 had been discovered on C3 by Maik. Then there was another lightning hit and I took the hint to quit before the computer blew up. This was my first discovery from home and although not an original one it is nice to make an independent find. I also made an independent discovery of 171 on July 2, originally not knowing about Terry's find, but on checking noted that it had been found on July 1 so thought it might be a different object.
Discovery positions for three more SOHO Kreutz sungrazers, C/1998 K16, 1998 K17 and 2000 M2, (SOHO-144 to 146, discovered by Michael Oates) further details of which are contained on MPEC 2000-N17: 1998 May 29.356 UT, R.A. = 4 24.1, Decl. +19 57 (equinox 2000.0); May 31.040, 4 27.8, +20 01; 2000 June 18.208, 5 44.1, +21 47. [IAUC 7450, 2000 July 8]
Discovery positions for five more SOHO Kreutz sungrazers, (1998 L2, 1998 L3, 1998 L4, 1998 L5, 1998 L6) are given on IAUC 7451 [2000 July 11] with details on MPEC 2000-N25.
1998 UT R.A. (2000) Decl. Comet
June 3.519 4 44.5 +20 36 C/1998 L2
4.087 4 46.5 +20 40 C/1998 L3
4.936 4 49.9 +20 44 C/1998 L4
5.401 4 51.4 +20 48 C/1998 L5
5.791 4 52.9 +20 51 C/1998 L6
D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard
Space Flight Center, reports observations of twelve more Kreutz sungrazing
comets detected with the SOHO/LASCO C2 coronagraph. The 1998 and 1999
comets were found by M. Oates from archival data in the SOHO website.
The 2000 comets were found in current data in the website by M. Meyer
(C/2000 M3), by Meyer and M. Boschat (C/2000 M4) and by A. Mimeev and
P. Shkreby (C/2000 M5). Positions have been measured by D. Hammer (in
collaboration with Biesecker in the case of the very faint and diffuse
object C/2000 M3) and reduced by B. G. Marsden. Discovery positions follow.
The complete measurements and orbital elements are given on MPEC 2000-N26.
[IAUC 7452, 2000 July 11]
1998 UT R.A. (2000) Decl. Comet
June 6.644 4 54.7 +20 50 C/1998 L7
8.334 5 02.0 +21 02 C/1998 L8
12.226 5 18.7 +21 21 C/1998 L9
19.414 5 46.8 +21 44 C/1998 M8
21.622 5 55.3 +21 45 C/1998 M9
23.644 6 02.9 +21 59 C/1998 M10
1999 UT R.A. (2000) Decl. Comet
June 1.299 4 34.6 +20 18 C/1999 L6
3.129 4 40.5 +20 25 C/1999 L7
6.310 4 54.2 +20 53 C/1999 L8
2000 UT R.A. (2000) Decl. Comet
June 19.347 5 49.0 +21 41 C/2000 M3
22.121 5 59.9 +21 38 C/2000 M4
24.132 6 07.0 +22 00 C/2000 M5
D. A. Biesecker, Emergent Information Technologies, Inc., and Goddard Space Flight Center, reports observations of three more Kreutz sungrazing comets (2000 M6, 2000 M7, 2000 M8) detected with the SOHO/LASCO coronagraphs (C2 alone for the first, both C3 and C2 for the others). Detections were by M. Meyer, by H. Luethen and Meyer and by Biesecker, respectively. Discovery positions follow. Complete measurements (by D. Hammer, reduction by B. G. Marsden) and orbital elements are given on MPEC 2000-N31. [IAUC 7453, 2000 July 13]
2000 UT R.A. (2000) Decl. Comet
June 25.479 6 12.9 +21 46 C/2000 M6
26.471 6 14.9 +20 26 C/2000 M7
27.779 6 20.8 +21 18 C/2000 M8
Following the item on IAUC 7453, three more Kreutz sungrazing comets (1999 H5, 2000 M9, 2000 N1) have been detected with the SOHO/LASCO coronagraphs (C2 alone for the first, both C3 and C2 for the others). Detections were by M. Oates (in archival data), by M. Meyer, and by T. Lovejoy and M. Boschat, respectively. Discovery positions follow. Details are on MPEC 2000-N34. [IAUC 7458, 2000 July 14]
1999 UT R.A. (2000) Decl. Comet
Apr. 24.455 2 12.5 +11 43 C/1999 H5
2000 UT R.A. (2000) Decl. Comet
June 30.971 6 31.6 +20 16 C/2000 M9
July 1.929 6 34.8 +19 24 C/2000 N1
Three more SOHO comets (1999 G3, 1999 G4 and 1999 H6) were confirmed on IAUC 7458 [2000 July 18]: D. Hammer reports measurements of three more Kreutz sungrazing comets from SOHO LASCO C2 data (cf., e.g., IAUC 7452, 7454), all found by M. Oates from archival data on the SOHO website. The discovery observations are given below, while MPEC 2000-O06 contains the fully reduced observations and orbital elements (by B. G. Marsden).
1999 UT R.A. (2000) Decl. Comet
Apr. 2.021 0 50.9 + 3 58 C/1999 G3
3.496 0 56.3 + 4 31 C/1999 G4
28.729 2 27.6 +12 59 C/1999 H6
Further to IAUC 7458, D. Hammer provides measurements of four comets found by M. Oates (1999 G5, 1999 H7, 1999 J12, 1999 X2) in archival images obtained in 1999 with the SOHO C2 telescope only and of one comet found by M. Meyer (2000 N2) in real-time SOHO C3 telescope data. The discovery observations for these Kreutz sungrazers are given below, while MPEC 2000-O10 contains the fully reduced observations and orbital elements (by B. G. Marsden). [IAUC 7459, 2000 July 20] Addendum. On IAUC 7459, it should be added that P. Shkreby also independently found C/2000 N2 in real-time SOHO website data. [IAUC 7481, 2000 August 24]
1999 UT R.A. (2000) Decl. Comet
Apr. 11.246 1 24.4 + 7 16 C/1999 G5
20.413 1 57.3 +10 21 C/1999 H7
May 3.035 2 43.2 +14 10 C/1999 J12
Dec. 3.896 16 42.2 -23 41 C/1999 X2
2000 UT R.A. (2000) Decl. Comet
July 8.221 7 00.0 +20 51 C/2000 N2
Further to IAUC 7459, D. Hammer provides measurements of six comets found in archival images obtained in 1997 with the SOHO C2 telescope only. M. Oates found C/1997 J3, C/1997 J4, and C/1997 K3; X. Leprette found C/1997 L5 and C/1997 M3; and Hammer found C/1997 K4. The discovery observations for these Kreutz sungrazers are given below, while MPEC 2000-P18 contains the fully reduced observations and orbital elements (by B. G. Marsden). [IAUC 7472, 2000 August 3]
1997 UT R.A. (2000) Decl. Comet
May 10.397 3 08.7 +16 16 C/1997 J3
10.397 3 11.8 +16 28 C/1997 J4
25.905 4 09.5 +19 34 C/1997 K3
31.777 4 34.2 +20 20 C/1997 K4
June 12.097 5 16.7 +21 34 C/1997 L5
28.603 6 24.5 +21 58 C/1997 M3
On IAUC 7479 D Hammer reported the measurements of two more Kreutz
sungrazing comets found by M. Boschat in SOHO C3 website images,
with the discovery positions given below. MPEC 2000-Q08 contains
the reductions and orbital elements by Marsden. [2000 August 21]
Comet 2000 UT R.A. (2000) Decl.
C/2000 P1 Aug. 6.654 8 52.0 +15 16
C/2000 P2 14.721 9 19.2 +12 49
Further to IAUC 7479, D. Hammer has provided measurements of
12 more Kreutz sungrazing comets detected by SOHO instruments
(discovery positions given below with citations to MPECs containing
the reduced measurements and orbits by B. G. Marsden). The comets
were found in archival data by Hammer (C/1998 G8), M. Oates (the
remaining 1997 Apr. and 1998 Apr. objects), and X. Leprette (C/1997
M4, C/1997 N3). [IAUC 7480, 2000 August 23]
Comet 1997 UT R.A. (2000) Decl. MPEC C/1997 G3 Apr. 4.103 1 00.5 + 4 50 2000-Q06 C/1997 G4 5.439 1 05.4 + 5 20 2000-Q06 C/1997 G5 5.826 1 06.4 + 5 28 2000-Q06 C/1997 G6 11.177 1 26.1 + 7 21 2000-Q06 C/1997 M4 June 17.685 5 40.8 +21 47 2000-Q06 C/1997 N3 July 4.670 6 49.2 +21 50 2000-Q06 Comet 1998 UT R.A. (2000) Decl. MPEC C/1998 G5 Apr. 6.368 1 07.9 + 5 37 2000-Q07 C/1998 G6 6.810 1 09.1 + 5 55 2000-Q07 C/1998 G7 7.491 1 11.0 + 5 54 2000-Q07 C/1998 G8 9.614 1 19.6 + 6 53 2000-Q08 C/1998 H3 26.496 2 20.0 +12 21 2000-Q07 C/1998 H4 27.941 2 25.4 +12 48 2000-Q07
Orbits for 1997 G3, 1997 G4, 1997 G5, 1997 G6, 1997 M4 and 1997 N3 were announced on MPEC 2000 Q06. Orbits for 1998 G5, 1998 G6, 1998 G7, 1998 H3 and 1998 H4 were announced on MPEC 2000 Q07. Orbits for 1998 G8, 2000 P1 and 2000 P2 were announced on MPEC 2000 Q08. Orbits for 1996 E2, 1997 K5 and 1997 K6 were given on MPEC 2000 Q18. An orbit for 1998 F2 was given on MPEC 2000 Q35.
Further to IAUC 7480, D. Hammer and D. Biesecker have provided
measurements of four more Kreutz sungrazing comets detected by SOHO
instruments; discovery positions and citations to the MPECs
containing the reduced measurements and orbits by B. G. Marsden are
given below. The 1997 objects (which both showed obvious tails)
were found by M. Oates in archival images, and the other two comets
were found by M. Meyer. All four comets were seen with the C2
coronagraph, but only C/1996 E2 (which showed cometary appearance
and a tail) was also seen with C3. [IAUC 7485, 2000 September 1]
Comet 1996 UT R.A. (2000) Decl. MPEC
C/1996 E2 Mar. 10.281 23 44.2 - 4 48 2000-Q18
Comet 1997 UT R.A. (2000) Decl. MPEC
C/1997 K5 May 20.264 3 46.9 +18 14 2000-Q18
C/1997 K6 31.188 4 31.0 +20 34 2000-Q18
Comet 1998 UT R.A. (2000) Decl. MPEC
C/1998 F2 Mar. 27.879 0 33.5 + 2 06 2000-Q35
Comet 2000 T1 (SOHO)
Further to IAUC 7445 and 7480, D. Biesecker reports
measurements for a Kreutz sungrazing comet found by J. Danaher in
LASCO C3 images at the SOHO website. Biesecker provides some V
magnitudes (estimated uncertainties 0.1 mag): Oct. 10.096 UT, 7.1;
10.221, 6.6; 10.263, 6.4; 10.321, 6.3. The reduced positions and
parabolic orbit by B. G. Marsden are given on MPEC 2000-T33. [IAUC 7506,
2000 October 10] A small fragment followed this comet and both were
visible in C2.
2000 UT R.A. (2000) Decl.
Oct. 9.821 12 29.0 - 8 45
COMETS C/1999 U6, C/2000 T3, C/2000 T4 (SOHO)
Further to IAUC 7445 and 7480, D. Hammer reports measurements
for three more Kreutz sungrazing comets. All were visible in the
LASCO C2 coronagraph, and C/2000 T4 was also seen in C3 images.
C/1999 U6, C/2000 T3, and C/2000 T4 were found by M. Oates, D.
Biesecker, and J. Danaher, respectively. The reduced positions and
orbits by B. G. Marsden are given on MPEC 2000-T46. [IAUC 7508, 2000 October 16]
Comet 1999 UT R.A. (2000) Decl.
C/1999 U6 Oct. 17.910 13 20.8 -10 09
Comet 2000 UT R.A. (2000) Decl.
C/2000 T3 Oct. 11.254 12 58.5 - 7 45
C/2000 T4 12.071 12 58.4 - 8 15
SOHO 2000 U1 to U4 were numbered on MPEC 2000-U38
Further to IAUC 7508, D. Biesecker and D. Hammer report the
discoveries of four additional Kreutz sungrazing comets. All four
were visible in the LASCO C2 coronagraph, and C/2000 U2 and C/2000
U3 were also seen in C3 images. C/2000 U1 and C/2000 U4 were found
by M. Oates; C/2000 U2 was found by M. Boschat; and C/2000 U3 was
found by J. Danaher. C/2000 U1 was described as faint, with no
tail evident. C/2000 U2 was fairly bright, with a long, thin tail.
The measurements were made by Hammer, and the reduced positions and
orbits by B. G. Marsden are given on MPEC 2000-U38. [IAUC 7514, 2000
November 1]
C/2000 U1 Oct. 21.393 13 37.0 -11 40
C/2000 U2 22.279 13 28.6 -13 13
C/2000 U3 24.029 13 41.4 -14 06
C/2000 U4 25.076 13 52.6 -13 09
Further to IAUC 7514 and 7485, D. Hammer reports his
measurements for eight additional Kreutz sungrazing comets found on
SOHO website images. Comet C/1997 T7 was found by X. Leprette; the
other seven objects were found by M. Oates. All eight comets were
seen in the C2 coronagraph, but only only C/1999 V2 was also
visible with the C3 instrument. The reduced observations and
orbital elements by B. G. Marsden are given on the MPECs cited
below. [IAUC 7517, 2000 November 6]
Comet 1997 UT R.A. (2000) Decl. MPEC C/1997 T6 Oct. 1.994 12 23.2 - 3 58 2000-V14 C/1997 T7 8.335 12 46.5 - 6 30 2000-V22 Comet 1999 UT R.A. (2000) Decl. MPEC C/1999 U7 Oct. 27.129 13 57.0 -13 32 2000-V14 C/1999 U8 29.326 14 05.9 -14 21 2000-V14 C/1999 U9 30.271 14 10.1 -14 44 2000-V14 C/1999 V2 Nov. 7.721 14 37.8 -18 29 2000-V22 C/1999 V3 14.746 15 15.3 -19 44 2000-V22 C/1999 V4 15.538 15 18.6 -19 54 2000-V22Further to IAUC 7514 and 7485, D. Hammer reports his measurements for several additional Kreutz sungrazing comets found by M. Oates on SOHO website images obtained with the C2 coronagraph. The reduced observations and orbital elements by B. G. Marsden are given on the MPECs cited below. [IAUC 7519, 2000 November 15]
Comet 1997 UT R.A. (2000) Decl. MPEC C/1997 T8 Oct. 8.741 12 48.6 - 6 44 2000-V35 C/1997 U2 Oct. 17.181 13 19.9 -10 07 2000-V36 C/1997 U3 Oct. 20.232 13 31.0 -11 09 2000-V36 C/1997 U4 Oct. 21.953 13 38.9 -11 50 2000-V36 C/1997 U5 Oct. 26.862 13 58.0 -13 41 2000-V36 C/1997 U6 Oct. 26.862 13 57.9 -13 42 2000-V36 C/1997 U7 Oct. 27.673 14 00.8 -13 54 2000-V36Further to IAUC 7519, D. Hammer reports his measurements for several additional Kreutz sungrazing comets found on SOHO website images obtained with the C2 coronagraph; the Nov. comets were found by M. Oates, and the Dec. comets were found by X. Leprette. The reduced observations and orbital elements by B. G. Marsden are given on the MPECs cited below. Regarding IAUC 7519 and MPEC 2000-V36, D. A. Biesecker informs us that he is not confident of the existence of comet C/1997 U6 (separated from C/1997 U5 by only 1' in position and by 0.01 day in T). [IAUC 7534, 2000 December 2]
Comet 1997 UT R.A. (2000) Decl. MPEC C/1997 V3 Nov. 1.921 14 25.7 -16 09 2000-W18 C/1997 V4 3.601 14 29.6 -16 20 2000-W18 C/1997 V5 8.564 14 53.3 -18 19 2000-W18 C/1997 V6 8.868 14 51.8 -18 08 2000-X13 C/1997 X3 Dec. 2.997 16 38.9 -23 52 2000-X13 C/1997 X4 3.080 16 39.5 -23 49 2000-X13 C/1997 X5 6.372 16 54.4 -24 14 2000-X13 C/1997 X6 10.329 17 13.9 -24 50 2000-X13 C/1997 Y1 20.889 18 02.7 -24 52 2000-X13Further to IAUC 7534, D. Hammer reports his measurements for several additional sungrazing comets found by X. Leprette (1997 comets) and by M. Oates (remaining comets) on SOHO website images obtained with the C2 coronagraph. The reduced observations and orbital elements by B. G. Marsden are given on the MPECs cited below. [IAUC 7536, 2000 December 5]
Comet 1997 UT R.A. (2000) Decl. MPEC C/1997 Y2 Dec. 21.336 18 05.4 -25 01 2000-X14 C/1997 Y3 22.877 18 12.4 -24 51 2000-X14 Comet 1998 UT R.A. (2000) Decl. MPEC C/1998 X3 Dec. 5.538 16 49.7 -24 12 2000-X13 C/1998 X4 7.854 17 00.2 -24 29 2000-X14 C/1998 X5 9.188 17 07.3 -24 36 2000-X14 C/1998 X6 9.704 17 09.5 -24 43 2000-X14 C/1998 X7 9.896 17 10.7 -24 44 2000-X14 C/1998 X8 11.896 17 19.6 -24 55 2000-X14 Comet 2000 UT R.A. (2000) Decl. MPEC C/2000 V3 Nov. 10.904 14 56.5 -19 46 2000-W18Further to IAUC 7536, D. Hammer reports his measurements for additional Kreutz sungrazing comets found by M. Oates (C/2000 W2) and M. Meyer (C/2000 W3) on SOHO website images obtained with the C2 coronagraph. The reduced observations and orbital elements by B. G. Marsden are given on MPEC 2000-X48. [IAUC 7548, 2000 December 23]
Comet 2000 UT R.A. (2000) Decl.
C/2000 W2 Nov. 16.271 15 25.6 -20 22
C/2000 W3 Nov. 18.229 15 35.0 -20 56