Sunday, June 1, 2008

Venus anti-transit of the Sun invisible(?) highlight of June

We are exactly half-way between the two transits of Venus of 2004 and 2012 - which means that in June 2008 Venus will pass behind the Sun during its superior conjunction. Astrophotographers have wondered for months whether it might be possible - with highly specialized equipment (don't try it with any regular optical system!!!Such experiments are really dangerous) - to image the tiny but very bright and fully illuminated disk of the planet approaching the solar limb and perhaps even catch it while disappearing behind the chromosphere. One system that may be able to do it is the Unigraph, a new refractor design with very little internal scattering which permits prominence photography in extreme resolution - and in white(!) light. (I once saw these images at a conference but just can't find any on the web.) Still unanswered is the question whether Venus would show up in such an image, together with the chromosphere or even a conveniently placed prominence ... The highlights of June 2008:
  • June 8, about 6:15 UTC: Venus disappears behind the solar limb as calculated with Horizons for a geocentric observer - should be nearly the same everyone on the planet.

  • June 8, evening UTC: The Moon (4 days old), Regulus and Saturn "line up", with Mars nearby.

  • June 10, around 1:00 UTC: Venus emerges again behind the Sun (because Venus is much farther from the Earth, such an 'antitransit' takes two days, not a few hours like a transit).

  • June 20: Dwarf planet Pluto in opposition to the Sun, at 13.9 mag.

  • June 30: One hundred years ago the Tunguska event hit Siberia - spare a thought for all those trees felled by an astronomically speaking insignificant cosmic airburst.
In other news according to CBET #1388 there is a 14.4 mag. supernova (SN 2008cq) in a nameless galaxy at -30° declination right now which on May 6 even had 13.4 mag. but was missed. • The brightness of Nova Oph 2008 is fluctuating wildly. • Comet Boattini has a needle-sharp ion tail in a May 30 picture (tailless pics from May 31, 30 and 28). • How STEREO saw the latest kamikaze comet, how a cosmological supernova hunt bagged many Kuiperoids as a by-product and how Cassini saw the Saturn storm on April 23. • And finally after yesterday's launch of Discovery the orbiter and its tank were widely seen over Europe as a video or trails show. Plus hi-res images of May 21 and 12.

1 comment:

vswmart said...

At 2° distance from the edge of the solar disk: