Comet C/1998 U5 (LINEAR)

Nov. 14.28: m1 = 8.5 (+/-0.2) Dia. 10' , DC = 4 , 20x80 B , MaunaKea (HI)
Nov. 15.49: m1 = 8.4 (+/-0.2) Dia. 8' , DC = 4 , 20x80 B , MaunaKea (HI)
Nov. 15.50: m1 = 8.2 (+/-0.2) Dia. 10' , DC = 4 , 7x50 B , MaunaKea (HI)
Nov. 17.41: m1 = 9.3 (+/-0.3) Dia. 8' , DC = 5 , 42x256 L, Dilli. (HI)
Nov. 17.43: m1 = 8.6 (+/-0.3) Dia. 10' , DC = 4 , 7x50 B , Dilli. (HI)
Nov. 21.33: m1 = 9.2 (+/-0.2) Dia. 7' , DC = 5 , 42x256 L, Dilli. (HI)
Nov. 21.34: m1 = 8.7 (+/-0.2) Dia. 10' , DC = 3 , 7x50 B , Dilli. (HI)
Nov. 22.31: m1 = 9.5 (+/-0.3) Dia. 8' , DC = 4 , 42x256 L, Dilli. (HI)
Nov. 23.34: m1 = 9.5 (+/-0.2) Dia. 8' , DC = 4 , 42x256 L, Dilli. (HI)
Nov. 23.36: m1 = 8.7 (+/-0.1) Dia. 10' , DC = 3 , 7x50 B , Dilli. (HI)
Nov. 25.31: m1 = 8.5 (+/-0.1) Dia. 10' , DC = 4 , 7x50 B, HalePohaku(HI)
Nov. 26.42: m1 = 8.4 (+/-0.2) Dia. 10' , DC = 3 , 7x50 B, HalePohaku(HI)
Dec. 06.24: m1 = 9.2 (+/-0.2) Dia. 7' , DC = 4 , 42x256 L, Dilli. (HI)
Dec. 11.28: m1 = 9.4 (+/-0.2) Dia. 6' , DC = 4 , 42x256 L, Dilli. (HI)
Dec. 11.29: m1 = 9.2 (+/-0.2) Dia. 8' , DC = 3 , 7x50 B, Dilli. (HI)
Dec. 14.28: m1 = 9.6 (+/-0.1) Dia. 4' , DC = 4 , 42x256 L, Dilli. (HI)
Dec. 17.28: m1 = 9.9 (+/-0.2) Dia. 4' , DC = 3 , 42x256 L, Dilli. (HI)
Dec. 19.25: m1 = 10.2 (+/-0.2) Dia. 3.5', DC = 3 , 42x256 L, Dilli. (HI)
Dec. 20.28: m1 = 10.3 (+/-0.2) Dia. 3.5', DC = 3 , 42x256 L, Dilli. (HI)
1999:
Jan. 10.24: m1 = 10.5:(+/-0.2) Dia. 1.5', DC = 2 , 42x256 L, Dilli. (HI)
Jan. 12.23: m1 = 10.8:(+/-0.2) Dia. 1.5', DC = 2 , 42x256 L, Dilli. (HI)
Jan. 14.23: m1 = 10.7 (+/-0.2) Dia. 2.0', DC = 2 , 42x256 L, Dilli. (HI)
Jan. 16.23: m1 = 11.1 (+/-0.2) Dia. 1.5', DC = 2 , 42x256 L, Dilli. (HI)
Mar. 14.64: m1 > 13.4 (Dia. 1') 169x256 L, Dilli. (HI)

comments

O-C(MPC32866): D(R.A.) = +0.6s (+-0.4s)
23.36 Nov. 98: D(Dec.) = -11" (+-5")
Discrepancy between 7x50 B and 42x256 L mags.: the contribution of (invisible to the 7x50 B) background stars in 10' of this dense Milky Way has been estimated to be 0.3 to 0.4 mag. on Nov. 23.36: this explains half of the difference and underlines the fact that brightness of comets against dense star fields may be OVERESTIMATED as seen in small instruments (Depending also on how many stars are included in the defocused reference ones?). This was also a problem for 22P/Kopff in June-July 1996.

Images: [46 K] Nov. 22.3: Drawing at 169x (25.6cm L) 10'x10', North is up [25K]

[29K] Nov. 25.4: 6min. 135mm F/2.5 Extracted from a 24x36mm slide... Sensia 400