Sunday, April 27, 2008

Holmes 6 months into the outburst: still there, still pics, still news ...

It was the night of Oct. 23, 2007 (UTC) when something - still largely unexplained, it seems from the lack of substantial papers - dramatic happened to comet 17P/Holmes. Six months later the comet is exceedingly hard to see visually, though photographers can still be lucky. And in May the comet will come close to several open star clusters in Auriga: perfect opportunities for some fare-well shots! And then there is the suspicion of a 45-day periodicity of (minor) outburts: Yesterday's TA EC #2442 reminds us that "[t]hree such 'mini-outbursts' have occurred so far and, if strictly periodic, the fourth one is expected around April 25. Observers equipped with telescopes of 0.25-m aperture or larger plus CCD camera are strongly encouraged to monitor this object [Holmes' near-nucleus region] which is now quite faint - around 17th magnitude in brightness. [...] Take a series of images over a period of 30-60 minutes as soon as the sky is suitably dark after sunset, and whilst the comet is fairly high in the sky." • For an easier target, meanwhile, try C/2007 W1 (Boattini), now at 7½ mag.

In other news Mercury is now in the evening sky, easier every day. Here are also the ongoing Saturn storm on Apr. 23, Jupiter in methane with a small scope, notes about Nova Sgr 2008's brightening and a paper on detailled monitoring of Polaris which reveals "an increase in the amplitude by about 30% from 2003-2006" in this classical Cepheid. • Mecca (where some now want the zero meridian to be moved ...) is among the most light-polluted spots on the whole planet - while Kielder Obs. claims to have the darkest skies in the U.K.

• How about Cygnus w/o stars, only nebulae? • Or a "flight" to the Virgo cluster? • What using the VLT(I) feels like. • Why "selling" stars is bad, period. • And now you can determine the number of civilizations in the galaxy all for yourself: by entering the right numbers into the Drake Formula ...

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