SJAA

Ephemeris

Comet Coments

Don Machholz


With a moderate-sized telescope, you could view a half-dozen comets on most nights during the next few months.

As predicted here last month, Comet Linear (1998 U5) outburst by nearly three magnitudes. It, and Comet Linear (1998 M5), both pass north of the sun and from the evening to the morning sky. Periodic Comet Giacobini-Zinner fades in the evening sky while Comet Williams fades in the morning sky. Comet Jager and Periodic Comet Harrington-Abell remain within fifteen degrees of each other as they pass through opposition on favorable visits through our part of the solar system.

C/1998 W1 (Spahr): Found on Nov. 16 by Timothy Spahr using a 16-inch Schmidt as part of the Catalina Sky Survey, this faint comet will be closest to the sun next month at 1.7 AU and orbits the sun every 6.7 years.

C/1998 W2 (Hergenrother): The same Catalina equipment was used to find this comet on Nov. 21. It remains faint.

C/1998 W3 (LINEAR): The LINEAR program found this faint comet on Nov. 25. It has a retrograde orbit and will be closest to the sun in Feb. 1999 at a distant 4.9 AU.

C/1939 TN (Vaisala-Oterma): A strange case of an object being discovered in 1939 which was treated as an asteroid but long suspected of being a comet. Recent observations show it is diffuse with a short tail; it is now classified as a comet. It orbits the sun every 9.5 years with a perihelion distance of 3.4 AU.

COMET HUNTING NOTES: Father Leo Boethin of the Philippines passed away on Sept. 15. He was the discoverer of Periodic Comet Boethin (85P/) on Jan. 4, 1975. It orbits the sun every eleven years.

EPHEMERIDES

C/1998 U3 (Jager)
Date(00UT)	R.A.	(2000)	Dec	El	Sky	Mag
01-02	06h37.8m	+37d42'	165d	M	10.5
01-07	06h33.4m	+36d46'	164d	E	10.5
01-12	06h29.3m	+35d44'	160d	E	10.5
01-17	06h25.7m	+34d38'	156d	E	10.5
01-22	06h22.8m	+33d28'	152d	E	10.5
01-27	06h20.6m	+32d17'	147d	E	10.5
02-01	06h19.3m	+31d05'	142d	E	10.5
02-06	06h19.0m	+29d53'	137d	E	10.5

21P/Giacobini-Zinner
Date(00UT)	R.A.	(2000)	Dec	El	Sky	Mag
01-02	00h14.3m	-23d55'	74d	E	10.1
01-07	00h38.0m	-23d33'	74d	E	10.4
01-12	01h00.5m	-22d58'	75d	E	10.7
01-17	01h21.8m	-22d11'	75d	E	11.0
01-22	01h41.8m	-21d16'	76d	E	11.2
01-27	02h00.8m	-20d13'	76d	E	11.5
02-01	02h18.8m	-19d06'	76d	E	11.8
02-06	02h35.8m	-17d56'	76d	E	12.1

52P/Harrington-Abell
Date(00UT)	R.A.	(2000)	Dec	El	Sky	Mag
01-02	07h18.6m	+40d45'	161d	M	10.6
01-07	07h15.3m	+40d20'	162d	M	10.6
01-12	07h12.0m	+39d46'	162d	E	10.5
01-17	07h09.0m	+39d03'	159d	E	10.5
01-22	07h06.4m	+38d13'	156d	E	10.5
01-27	07h04.6m	+37d16'	153d	E	10.6
02-01	07h03.7m	+36d13'	149d	E	10.6
02-06	07h03.8m	+35d07'	145d	E	10.7

C/1998 U5 (LINEAR)
Date(00UT)	R.A.	(2000)	Dec	El	Sky	Mag
01-02	21h11.1m	+17d34'	53d	E	9.9
01-07	21h09.7m	+16d33'	48d	M	10.1
01-12	21h08.7m	+15d46'	44d	M	10.3
01-17	21h08.1m	+15d07'	40d	M	10.5
01-22	21h07.6m	+14d37'	37d	M	10.7
01-27	21h07.3m	+14d14'	34d	M	10.9
02-01	21h07.1m	+13d57'	31d	M	11.1
02-06	21h06.9m	+13d44'	30d	E	11.2

C/1998 P1 (Williams)
Date(00UT)	R.A.	(2000)	Dec	El	Sky	Mag
01-02	12h45.7m	-03d59'	89d	M	9.3
01-07	12h34.7m	-00d30'	98d	M	9.3
01-12	12h21.2m	+03d34'	108d	M	9.3
01-17	12h04.7m	+08d13'	118d	M	9.3
01-22	11h44.9m	+13d22'	130d	M	9.4
01-27	11h21.7m	+18d49'	141d	M	9.4
02-01	10h55.4m	+24d13'	151d	M	9.6
02-06	10h26.8m	+29d08'	159d	M	9.7

C/1998 M5 (LINEAR)
Date(00UT)	R.A.	(2000)	Dec	El	Sky	Mag
01-02	18h57.1m	+41d34'	65d	E	9.4
01-07	18h59.9m	+43d03'	65d	M	9.3
01-12	19h02.9m	+44d45'	67d	M	9.3
01-17	19h06.2m	+46d41'	68d	M	9.2
01-22	19h09.6m	+48d53'	70d	M	9.2
01-27	19h13.1m	+51d21'	72d	M	9.1
02-01	19h16.9m	+54d07'	75d	M	9.1
02-06	19h20.7m	+57d12'	77d	M	9.0

Object:	Giacobini-Zinner	Jager	Williams	LINEAR (M5) 
	Harrington-Abell	Linear (U5)
Peri. Date:	199811 21.32107	1999 03 07.7714	1998 10 17.836	1999 
01 24.5733	1999 01 27.8772	1998 12 21.8912
Peri. Dist (AU):	1.0337095 AU	2.152631 AU	1.14674 AU 
	1.742213 AU	1.755993 AU	1.235763 AU
Arg/Peri (2000):	172.54569	179.4942	294.473 
	101.2873	138.8996	051.2248
Asc. Node (2000):	195.39930	303.8178	156.379. 
	333.3766	337.2882	066.6346
Incl (2000):	031.85856	019.0944	145.730 
	082.2285	010.2186	131.7425
Eccen:	0.7064344	0.652672	1.0	1.0	0.542909 
	0.983362
Orbital Period:	6.61 years	15.4 years	Long Period	Long 
Period	7.53 years	Long Period
Ref:	NK 629	MPC 32866	MPEC 32410	MPC 32410	MPC 
32595	MPEC 1998-W45
Epoch:	1998 11 21	1999 03 08	1998 10 17	1999 01 22 
	1999 01 22	1999 01 22
Absol. Mag/"n":	9.0/6.0	6.5/4.0	6.5/4.0	5.5/4.0	8.6/4.0	8.0/4.0

Don Machholz; last updated: 1998 Dec 16 Prev Next