Monday, April 30, 2012

Solar satellite "filmed" complete Nova Sgr 2012 outburst with high cadence!

This could be a first in nova research: When Nova Sagittarii 2012 alias PNV J17452791-2305213 erupted on April 21, the satellite STEREO B had the field firmly in its view, and from the inadventend high-cadence photometry an impressive lightcurve has been generated, showing the complete peak! Whether such a record is unprecedented isn't clear yet. The nova reached 8.8 mag. briefly; since the nova has faded a lot: discovery pictures here and here, early spectra here and here (strong H-Alpha) and reports here and here. • Also blazar OJ 287 is flaring and in a high optical state, though not brighter than 13.5 mag.

On the Sun a prominence & CME on April 22, a prominence and sunspot details on April 21, a prominence on April 17 and a famous prominence (more) on April 16. • The SDO has been in orbit for 2 years, generating lots of pretty pictures. • An EGU press conference on space weather forecasting (abstracts links and COMESEP's home), ISWI and another doom story, picked up here and here. • Hinode sees a pole asymmetry. • Camilla visited the stratosphere (not 'space'), generating publicity for NASA like here, here (7:10-42), here, here and even here.

The aurora was quite active around April 24 as images from Sweden, northern Germany, northwestern Ireland (more and more, a video [alt.]), Northern Ireland and Canada (video) show; more collections here and here. • Also a celebrated aurora timelapse from Norway, more here - and auroral ballooning (more) in Alaska (video). • Also a sky mystery that could be a venting satellite, a story on amateur spysat hunters, and the sad death of Dale Ireland (also here and here) - whose automatic weather timelapse algorithm keeps running ...

Minor bodies in the news: Comet Garradd on April 18, April 17 and April 16, plus Faulkes observations of the Rosetta target. • Trans-Neptunian star occultations til 2015. • Yet more evidence against the Dryas impact and the impact history of the Earth. • The Target Asteroids! project explained here, here, here and here, plus a study on capturing a NEO. • A great bolide over the U.S., dropping meteorites in old gold rush country, a Brazilian bolide and the usual Lyrids.

Planets now well placed - a long-term calculation of altitudes for Germany - are Saturn (April 21 [dito and dito], April 12 [dito] and near opposition pictures), Mars (on April 19, April 16, April 7 and March 29/30) and Venus: a deeep picture in the Pleiades and with the Moon - and Obama. • Being so bright and well-placed - and thus also the sky highlight of early May - Venus also caused various UFO alerts, notably on German TV (covered also here, here, here and here) or here. While Venus looks like this right now (or like this in the near IR), it's prone to video artefacts. • And talking about a misunderstood Venus, its role in a famous aircraft incident in Jan. 2011 is less clear than in all the news coverage e.g. here, here, here, here, here or here as reading the actual investigation report shows. • Finally Mercury & the Moon on April 19 from Oz.

Sunday, April 15, 2012

Big KBO Quaoar to occult pretty bright star - probably for Africa

It was the 3rd big Kuiper Belt Object discovered, after Varuna and Ixion - and on the morning of April 17 (50,000) Quaoar will occult an 11-mag. star: Such occultations by outer solar system bodies have often led to new insights. Previous hopes that the track might cut through Europe have faded with recent astrometry: Now it looks like that the zone where occultation by Quaoar as well as its moon Weywot can be observed had slipped south into central Africa. • For the first time aurora on Uranus has been imaged from great distance, namely with Hubble. • Saturn is in opposition: pictures of April 14 and April 12 - and for tonight at 1:30 UTC (April 16) a webcast is planned. • Meanwhile Jupiter has 'lost' several moons that didn't exist in the first place, of course.

The apparition of Mars is already fading, with the disk shrinking: images of April 14, April 8, April 1 (more), March 30, March 28 (another terminator cloud; also a better animation of March 20 and another and another March 28 picture), March 27 and March 25, plus a February to April montage. It has now turned out that the bright spot in Mare Acidalium mentioned last time was also seen in 2010 as well as 2008 & 10 - but not in 1995, the last opposition with similar geometry as the current one. • The passage of Venus near the Pleiades was imaged a lot: collections of April 2 ... 4 and March 31 ... April 3 - and a view from 1972, 5 'grand cycles' earlier. • Meanwhile the separation of Venus & Jupiter is large again, but there are conjunctions about annually, with a particularly close one in August 2016.

Near Earth Asteroid 2012 EG5 was observed widely during its April 1 Earth visit: a lightcurve, a picture and early analysis of taxonomy and spin rate - but no radar detection in spite of a well-determined orbit. • A long story on 2011 AG5 and why it's so hard to nail its orbit. • Comet Garradd on April 11: It's now in the 'paws' of UMa and was also observed by Swift, while 2011 FR143 has a cometary nature and P/2005 YJ126 (Catalina) has been recovered. • More on the Norwegian meteorite crash, a bolide in Texas on April 2 (which was real but the video was not), a multistation analysis of a Dutch bolide on March 27 and a German bolide on March 17. • Oh, and there was no Younger Dryas impact, period.

On the - rather inactive - Sun (the space wx April 4 ... 10) a fine limb eruption on April 15 from AR 1442 (more views & analysis and more), AR 1459 near the limb and another SDO 'tornado' on April 10/11. • From solar science corona cells (more), solar shape measurement by rolling SDO, joint IBEX/TWINS observations of a solar storm and alleged solar cycle weather effects. • The Arctic aurora season in ending quickly now (more and more): some parting shots from Scotland, the UK and Norway (more) - plus a fine 45-min documentary from German TV on aurora hunting in Scandinavia, describing various methods to go after it!

Finally the NASA space observatory data center has been named for Senator B. Mikulski which is well deserved as she fought hard for Hubble and the JWST - but it's merely a joke that a supernova was also named for her (as also claimed here and here). "No, supernovae are not named officially, only designated," the IAU's Central Bureau for Astronomical Telegrams has assured this blog: "This is evidently just a cute joke..." • And to close a wide view of the zodiacal light and assorted phenomena, glorious images of contrails (tons of them) with light effects and turbulence effects - and a timelapse movie of geostationary satellites ... with the Alps in the foreground!