SJAA

Ephemeris

Comet Comments for October 1999

Don Machholz


Comets 1998 T1 (LINEAR) and 1999 N2 (Lynn) are fading in our evening sky, but three other comets are visible in our instruments. We have been watching Comets Lee and Temple 2, now we can see the new Comet LINEAR (1999 J3). Discovered on May 12, it has left the polar region and entered our morning sky, brightening rapidly. Imagine my surprise when I recently swept it up while comet hunting, not knowing it would be so bright.

Only one new comet has been found, and this was by SOHO on August 5. No comets were found during the total solar eclipse of August 11.

COMET HUNTING NOTES: The tilt of the comet's orbit is called the inclination, and it is measured in degrees. A comet going in earth's orbit has a 0 degree inclination, while one going in the opposite direction has a 180 degree inclination. An object traveling perpendicular to earth's orbit (as does Comet Hale-Bopp) has an inclination of 90 degrees. The average inclination for the last 81 visually found comets is 84 degrees. There is a slight grouping of comets in the 40-50 degree range and a dearth of comets near 100 degrees. I suspect this is a true picture of comet orbit distribution, since comet hunter sweeping patterns would not seem to favor (and unfavor) these particular inclinations.

Comet Ephemerides

C/1999 H1 (Lee)

Date(00UT) R.A. (2000) 	Dec    	El    Sky 	Mag
09-09	05h33.3m	+54d58'	82d	M	8.4
09-14	04h50.1m	+57d36'	92d	M	8.4
09-19	03h51.4m	+59d13'	102d	M	8.5
09-24	02h40.3m	+58d43'	114d	M	8.6
09-29	01h29.8m	+55d19'	125d	M	8.7
10-04	00h32.2m	+49d27'	135d	M	9.0
10-09	23h50.6m	+42d22'	141d	M	9.2
10-14	23h21.8m	+35d16'	142d	E	9.6
10-19	23h02.0m	+28d51'	140d	E	9.9
10-24	22h48.4m	+23d23'	135d	E	10.3
10-29	22h39.0m	+18d51'	129d	E	10.7
11-03	22h32.6m	+15d10'	123d	E	11.0
11-08	22h28.4m	+12d09'	117d	E	11.4

Periodic Comet Tempel 2 (P/10)

Date(00UT) R.A. (2000) 	Dec    	El    Sky	Mag
09-09	18h11.8m	-29d01'	107d	E	10.7
09-14	18h25.2m	-29d54'	105d	E	10.8
09-19	18h39.3m	-30d37'	103d	E	10.9
09-24	18h54.1m	-31d09'	101d	E	11.0
09-29	19h09.4m	-31d31'	99d	E	11.1
10-04	19h25.0m	-31d41'	98d	E	11.2
10-09	19h40.9m	-31d41'	96d	E	11.3
10-14	19h56.9m	-31d31'	95d	E	11.4
10-19	20h12.9m	-31d11'	93d	E	11.6
10-24	20h28.9m	-30d41'	92d	E	11.7
10-29	20h44.6m	-30d03'	90d	E	11.8
11-03	21h00.0m	-29d16'	89d	E	12.0
11-08	21h15.2m	-28d23'	88d	E	12.1

1999 J3 (LINEAR)

Date(00UT) R.A. (2000) 	Dec    	El    Sky	Mag
09-04	08h39.9m	+49d15'	50d	M	10.1
09-09	08h34.9m	+46d29'	53d	M	9.8
09-14	08h29.5m	+43d11'	56d	M	9.5
09-19	08h23.7m	+39d05'	59d	M	9.3
09-24	08h17.5m	+33d54'	63d	M	9.0
09-29	08h10.7m	+27d08'	67d	M	8.8
10-04	08h02.8m	+18d09'	71d	M	8.5
10-09	07h53.5m	+06d13'	77d	M	8.3
10-14	07h41.9m	-08d55'	82d	M	8.2
10-19	07h26.8m	-26d03'	87d	M	8.3
10-24	07h06.1m	-42d25'	91d	M	8.6
10-29	06h37.1m	-55d39'	92d	M	9.0
11-03	05h55.8m	-65d07'	91d	M	9.5
11-08	04h59.2m	-71d08'	90d	M	10.0

Elements

Object:			Lee
Peri. Date:		1999 07 11.1725
Peri. Dist (AU):	0.708101 AU
Arg/Peri (2000):	040.7006 deg.
Asc. Node (2000):	162.6490 deg.
Incl (2000):		149.3533 deg.
Eccen:			0.99974
Orbital Period:		142,000 yrs.
Ref:			MPC 35553
Epoch:			1999 08 10
Absol. Mag/"n":		7.0/4.0

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

Object:			LINEAR (1999 J3)
Peri. Date:		1999 09 20.1699
Peri. Dist (AU):	0.9774750AU
Arg/Peri (2000):	161.9509 deg.
Asc. Node (2000):	229.0006 deg.
Incl (2000):		101.6670 deg.
Eccen:			1.0
Orbital Period:		Long Period
Ref:			MPC 35553
Epoch:			1999 09 20
Absol. Mag/"n":		9.4/4.0

CC254.TXT 09-07-99 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