SJAA

Ephemeris

Comet Comments

Don Machholz


Comet Lee travels north of the sun and into the morning sky. Meanwhile, Comet LINEAR (1998 T1) and Periodic Comet Tempel 2 are in our evening southern sky.

The SOHO satellite discovered eight sungrazer comets this month, all were headed into the sun. The LINEAR program in New Mexico has found three more faint comets while the Sloan Digital Sky Survey has found one faint comet.

Comet Hunting Notes: Fifty-two of the 80 comets discovered by amateurs over the past 24 years have perihelion distances of less than 1.0 Astronomical Unit (AU). At the extremes we have a minimum distance of 0.11 AU for a comet found by me in 1985, and a maximum distance of 3.32 AU for a comet found by K. Cernis in 1983. Now contrast that to the SOHO satellite whose discoveries have perihelion distances of under .01 AU and to LINEAR, which is finding many comets with perihelion distances of greater than 3.0 AU.

Ephemerides

C/1999 H1 (Lee)
Date(00UT) R.A. (2000) Dec	El     Sky  Mag
07-06	08h02.3m	+26d42'	15d	E	6.7
07-11	07h56.7m	+28d52'	11d	E	6.7
07-16	07h50.6m	+30d55'	10d	E	6.7
07-21	07h44.2m	+32d52'	13d	M	6.9
07-26	07h37.6m	+34d44'	18d	M	7.0
07-31	07h30.6m	+36d33'	24d	M	7.2
08-05	07h23.3m	+38d23'	30d	M	7.4
08-10	07h15.4m	+40d16'	36d	M	7.6
08-15	07h06.5m	+42d15'	42d	M	7.8
08-20	06h56.0m	+44d23'	50d	M	8.0
08-25	06h43.1m	+46d43'	57d	M	8.1
08-30	06h26.5m	+49d17'	65d	M	8.2
09-04	06h04.2m	+52d05'	73d	M	8.3
09-09	05h33.4m	+54d58'	82d	M	8.4

C/1998 T1 (LINEAR)
Date(00UT) R.A. (2000) Dec	El     Sky  Mag
07-06	17h54.3m	-47d47'	152d	E	9.0
07-11	16h12.9m	-43d42'	136d	E	8.3
07-16	15h13.5m	-37d47'	121d	E	8.8
07-21	14h40.0m	-32d51'	109d	E	9.2
07-26	14h20.0m	-29d10'	100d	E	9.7
07-31	14h07.5m	-26d28'	91d	E	10.0
08-05	13h59.4m	-24d28'	84d	E	10.4
08-10	13h54.0m	-22d58'	78d	E	10.7
08-15	13h50.5m	-21d49'	72d	E	11.0
08-20	13h48.4m	-20d57'	66d	E	11.3
08-25	13h47.1m	-20d16'	61d	E	11.6
08-30	13h46.6m	-19d45'	56d	E	11.8
09-04	13h46.6m	-19d21'	51d	E	12.0
09-09	13h47.0m	-19d03'	46d	E	12.3

Periodic Comet Tempel 2 (P/55)
Date(00UT) R.A. (2000) Dec	El     Sky  Mag
07-06	17h03.1m	-09d50'	150d	E	10.7
07-11	17h01.1m	-11d15'	145d	E	10.6
07-16	17h00.2m	-12d46'	141d	E	10.6
07-21	17h00.3m	-14d22'	137d	E	10.5
07-26	17h01.7m	-16d00'	133d	E	10.5
07-31	17h04.3m	-17d40'	129d	E	10.5
08-05	17h08.3m	-19d20'	125d	E	10.5
08-10	17h13.7m	-20d59'	122d	E	10.5
08-15	17h20.3m	-22d34'	119d	E	10.5
08-20	17h28.3m	-24d05'	116d	E	10.5
08-25	17h37.5m	-25d30'	114d	E	10.6
08-30	17h47.9m	-26d48'	111d	E	10.6
09-04	17h59.3m	-27d59'	109d	E	10.7
09-09	18h11.8m	-29d01'	107d	E	10.7

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":		8.8/4.0

Object: P/Tempel 2
Peri. Date:		1999 09 08.41663
Peri. Dist (AU):	1.481683 AU
Arg/Peri (2000):	195.02016 deg.
Asc. Node (2000):	118.21147 deg.
Incl (2000):		011.97662 deg.
Eccen:			0.5228125
Orbital Period:		5.47 years
Ref: 			NK640
Epoch:			1999 08 10
Absol. Mag/"n":		9.0/5.0
Don Machholz (530) 346-8963
DonM353259@aol.com.
Web Page: http://members.aol.com/cometcom/index.html


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