SJAA

Ephemeris

Comet Comments

Don Machholz


A new comet has been discovered in the Southern Hemisphere. It is visible in our evening sky, while Comet LINEAR (1998 T1), dimmer than expected, is in the morning sky.

Steve Lee visually discovered a new comet in the southern sky while observing from a star party in Australia. Then at magnitude 9, the comet, C/1999 H1 (Lee) should brighten as it continues to move north and then behind the sun. It will emerge into our morning northern sky in late July.

The SOHO satellite found two new comets. One (C/1999 G2) was found on April 13 and the other (C/1999 H2) on April 19. Both disappeared.

The LINEAR program found two more comets. The one found on April 7, C/1999 G1 was closest to the sun last September at 4.4 AU and remains faint. The other (C/1999 H3) was found on April 22 and will be closest to the sun this August at 3.5 Astronomical Units. It may brighten to magnitude 13.

The Catalina Program found a new comet on March 23. C/1999 F1 is still nearly three years away from perihelion at 5.8 AU. It is magnitude 19 now, and may brighten by then to magnitude 14.

COMET HUNTING NOTES: Comet Lee is one of four comets found by amateurs at star parties during the past 25 years. In 1975 Doug Berger found Comet Kobayashi-Berger-Milon while looking for M 2 at a San Jose Astronomical Association event. In 1985 I found Comet Machholz (1985e) at the Riverside Telescope Makers' Conference. In 1995, at a star party in Arizona, Thomas Bopp found a comet near M 70. Three of these four finds were accidental finds, and those three comets reached magnitude seven or brighter.

Ephemerides

C/1999 H1 (Lee)

Date(00UT) R.A. (2000)     Dec    El	Sky	  Mag
05-07	09h36.6m	-38d48'	 109d	E	  7.8
05-12	09h14.1m	-27d31'	  98d	E	  7.7
05-17	08h58.8m	-17d22'	  88d	E	  7.6
05-22	08h48.0m	-08d49'	  78d	E	  7.6
05-27	08h40.2m	-01d49'	  69d	E	  7.5
06-01	08h34.1m	+03d54'	  61d	E	  7.5
06-06	08h29.2m	+08d38'	  53d	E	  7.4
06-11	08h24.8m	+12d38'	  46d	E	  7.3
06-16	08h20.8m	+16d05'	  39d	E	  7.1
06-21	08h16.6m	+19d07'	  33d	E	  7.0
06-26	08h12.3m	+21d51'	  27d	E	  6.9
07-01	08h07.5m	+24d22'	  21d	E	  6.7
07-06	08h02.3m	+26d42'	  15d	E	  6.7
07-12	07h56.7m	+28d52'	  11d	E	  6.7 

C/1998 T1 (LINEAR)

Date(00UT) R.A. (2000)     Dec     El	Sky	Mag
05-07	23h36.5m	-04d04'	  53d	M	11.5
05-12	23h35.9m	-04d44'	  58d	M	11.2
05-17	23h34.7m	-05d33'	  64d	M	11.0
05-22	23h32.6m	-06d36'	  69d	M	10.7
05-27	23h29.3m	-07d58'	  76d	M	10.4
06-01	23h24.4m	-09d45'	  82d	M	10.1
06-06	23h16.9m	-12d09'	  90d	M	 9.8
06-11	23h05.6m	-15d28'	  98d	M	 9.4
06-16	22h47.9m	-20d06'	 108d	M	 9.0
06-21	22h18.7m	-26d42'	 121d	M	 8.6
06-26	21h27.6m	-35d32'	 137d	M	 8.2
07-01	19h57.8m	-44d36'	 153d	M	 8.0
07-06	17h54.3m	-47d47'	 152d	E	 8.0
07-11	16h12.9m	-43d42'	 136d	E	 8.3 

Elements

Object:			Lee 	
Peri. Date:		1999 07 11.1657
Peri. Dist (AU):	0.708308 AU
Arg/Peri (2000):	040.6689 deg.
Asc. Node (2000):	162.6375 deg.
Incl (2000):		149.3558 deg.
Eccen:			1.00
Orbital Period:		Long Period
Ref:			MPC 34421
Epoch:			1999 07 11
Absol. Mag/"n":		7.0/4.0	 

Object:			LINEAR (T1)
Peri. Date:		1999 06 25.2578
Peri. Dist (AU):	1.468118 AU
Arg/Peri (2000):	226.3361 deg.
Asc. Node (2000):	153.3540 deg.
Incl (2000):		170.1601 deg.
Eccen:			0.99915
Orbital Period:		71,000 years
Ref:			MPC 33451
Epoch:			1999 01 22
Absol. Mag/"n":		7.8/4.0 
Web Page: http://members.aol.com/cometcom/index.html


Don Machholz; last updated: October 04, 2007 Prev Next