Joe asked:
Kurt, What will it be like on the 24th, which is supposed to be its closest approach? Thanks, Joe
From my avenues urban light polluted location, I tried for 144P-Kushida before midnight 2-18 and was cloud throttled. Checking back at 3:15am for Comet C/2007 N3 Lulin from the same location, it was a clear night but with heavy residual water vapor that exacerbated the urban light pollution effect. gam Vir (Porrima) at 3.6v was the near-field naked eye limiting magnitude. Using a cheap after-work 4.25 reflector with alt-az computer control, after synching on gam Vir (Porrima), the scope easily zeroed on Lulin about 3 degs south in alt and just east of Porrima. At 40x, Lulin was faintly visible as an indistinct 10'-15' smudge contrasting slightly with the light polluted sky brightness. At higher magnifications it may be possible to miss Lulin, because it will fade against the light pollution. Lulin was within the same 1 deg TFOV at 7.8v SAO138928. A dark cloth hood improved visibility by reducing light intrusion of surrounding neighbor house lamps. Using the cloth hood brought out some central nucleus contrast as opposed to the halo. A broadband LPR filter slightly improved contrast; an OIII filter did not. I used the scope's red dot finder to fix the naked-eye position of the comet in the washed out sky relative to Porrima. Then using 8x35 binos, I was able to quickly find Lulin, again as a faint smudge on the urban sky. Had I not prelocated it with the scope, I may not have properly acquired it with the binos alone due its subtle contrast with the light polluted sky. Wraping my head with the dark cloth and trapping the cloth with my hands as they held the binoculars also helped the visibility of Lulin in the binos by excluding intrusive light from neighborhood house lamps. John Pane 2-17 Lulin video with geostats streaking by (from SeeSat list) http://www.cs.cmu.edu/~pane/lulin/movie/ I decided to get up in the wee hours for this one, having checked the NOAA IR Stat image that showed a big nasty storm sitting off the west coast of California and Oregon and coming our way. It seemed like there would be a temporary cloudless zone (but with high water vapor) between that new weather front and the one that just departed - which luckily turned out to be the case. Checking the jet stream and NOAA IR satellite images around noon today, I see the storm system is still sitting there, trapped by the jet stream. I guess it will break free and be here tonight. If the storm does not arrive this evening, fast-mover Lulin will be about 3 degs south alt of the midpoint of a line between gam Vir and eta Vir at 3:00am tomorrow morning. It will be within a 1 deg TFOV of 8 mag star SAO138796 (HD108474). If the storm arrives late in the evening, but it is clear around sunset, 144P-Kushida may be an option just after nautical twilight. Clear skies - Kurt