Thursday, January 31, 2008

Changes on Mars noted: part of Solis Lacus brightened

Comparing Mars images from 2003 and 2005 with the view this January, B. Gährken has found evidence that part of the "eye of Mars" is much brighter now. Check out the Mars image archives at ALPO Japan and Mars Watch to see many other excellent images from the current apparition!

In other news the Cassini project released today a very cool interactive application named CASSIE that allows you to see Cassini in motion.

Only 14 mag. - so far: rare outburst of AQ CMi

The rarely outbursting star AQ CMi is in outburst, reports the AAVSO: It was at m(vis) = 14.6 mag. on 2008 Jan 31 11:28 UT. For the AAVSO it "is unclear whether the current outburst is a normal outburst or a superoutburst. The last confirmed normal outburst occurred on February 28, 2000, and the last confirmed superoutburst occurred in March 1997, nearly 11 years ago."

In other news only negative reports of yesterday's stellar occultation by asteroid Vineta have come in so far, i.e. the star was seen but did not disappear. Euraster should have a tabulation of reports soon. A long trail of asteroid 2007 TU24 near Messier 81 has been photographed, while Venus and Jupiter are getting ever closer as some pictures show.

And in Austria amateur astronomers had the opportunity to observe with MOST, a small Canadian astronomy satellite: The results of the 6 programs were recently presented at a ceremony in Vienna.

Wednesday, January 30, 2008

Early birds only: Watch Venus & Jupiter meet at dawn

Over the coming few days, the two brightest planets will come pretty close together, but - from mid-northern latitudes - the pair can only be seen low on the horizon at dawn: Science@NASA, Sky & Tel., Universe Today, Astronomy, and the AstroBlogger have previews.

And Europeans should not forget the rare stellar occulation by a small asteroid tonight!

More images, animations of TU24 racing by

Images and movies from around the world are now appearing on SpaceWeather which show the NEA in Earth's sky - sometimes in the vicinity of several galaxies. A visual report says that at x78 the motion in the sky was evident. And if you were on Mars you could witness another close asteroid visit today ...

New radar image of TU24, trail near M 81/82 just in!

The JPL has just released a new radar image of the asteroid jointly obtained by Arecibo and Greenbank - and one amateur, fighting clouds, caught the asteroid's faint trail near the galaxies Messier 81 and 82.

Tuesday, January 29, 2008

Asteroid 2007 TU24 caught passing close to galaxy Messier 33

One astrophotographer succeeded in catching the trail of fast-moving NEA 2007 TU24 close to the spiral galaxy M 33. Tonight its path will take it close to the galaxies M 81 and 82! (The map was calculated for Germany; the hourly tick marks started at 16:00 UTC on top.) News coverage has 'taken off' now around the world (while some pseudoscientists have blown it again :-) and should do so once more: when better radar images become available.

7th mag.: major outburst of eruptive EX Lupi!

"The pre main-sequence eruptive variable EX Lup [...] appears to be undergoing a major outburst, exceeding the previous brightest maximum recorded in 1955," reports the AAVSO: "Albert Jones (Nelson, NZ) reports that EX Lup reached a visual magnitude of 7.9 on 2008 Jan 29.66 UT [...]. This exceeds the previous brig[h]test recorded magnitude of this object (m(vis) = 8.7 [...]) in 1955-56." EX Lupi is the prototype of the "EXor" class, which are pre-main-sequence variables that normally remain at minimum light, but are subject to relatively brief (a few months to a few years) flare-ups of several magnitudes amplitude; the current outburst had first been reported a week ago.

Asteroid 2007 TU24 close to Earth, observed visually with small telescopes

Even with a 6-inch telescope the "mammoth" - not really, at just 250 meters ... - NEA was easy to see tonight, as it moved among the stars. A photo sequence shows its high angular speed.

Holmes has entered the STEREO field of view

The very fuzzy comet - 3+ months into its bizarre outburst - can now be observed with SECCHI, coronographic cameras on STEREO. You need to log on to the comets mailing list (which is a good idea anyway :-) see the images from that archive.

Monday, January 28, 2008

How recurrent nova RS Oph inaugurated Keck Interferometer science

Observations of dust - or the lack thereof - around the recurrent nova RS Ophiuchi during its last blast two years ago led to the first scientific observations with the Keck Interferometer thanks to its nulling mode.

Sunday, January 27, 2008

Secret U.S. satellite to make uncontrolled reentry - what do we know?

Not much at the moment: The satellite in question is probably an experimental reconnaissance satellite known as NROL-21 which was launched in Dec. 2006 and ran into trouble only a month later. Now it is predicted to reenter one month from now - but since the satellite was and is classified, information is scant. Given the large size of the satellite, the reentry could either turn into a spectacular sky phenomenon or something less pleasant - the whole affair is already being compared to Skylab's fiery fall onto Western Australia in 1979. Given NROL-21's orbital inclination of 58.5 degrees, much of the planet is in 'the zone' ...

Here comes NEA 2007 TU24!

First amateur images of the Near Earth Asteroid approaching Earth have been published, e.g. on where it is shown at 16th mag. While the brightness will grow to 10.3 mag. on January 30, one day after closest approach, the high angular speed and proximity to Earth (parallax!) will make observations difficult. Mass media coverage is on the increase, however, with recent articles in the Star Bulletin, the German Press Agency, the Times and Sky & Tel. Or watch an entertaining video lecture on the non-danger posed by the thing ...

Europe, Jan. 30: 5 mag. star to be occulted by small asteroid!

A rare occultation of a (faintly) naked-eye star (5.7 mag.) by a small (18 km) asteroid will be visible in several European countries on the evening of Jan. 30: Since the track uncertainty is greater than the asteroid diameter, many observers will miss this rare event, but the more people look, the more likely someone will see the star disappear (for at most 1.2 seconds). See these maps for the world, all of Europe and Germany (where everyone not in the deep red zone should look at the critical time) for details!

Saturday, January 26, 2008

Possible - and faint - dwarf nova in Hydra

The Electronic Telegram No.1225 of the IAU CBAT reports about "a variable star (mag 13.3) [...] at R.A.=8h45m55s.08, Decl.=+3o39'29".7", found on Jan. 19. "An image on Jan. 25.516 [...] shows that the star had faded to mag about 14.2." Further details were given earlier by the AAVSO.

29P/Schwassmann-Wachmann in outburst: a tiny Holmes

After an outburst last Dec. 29 the comet - which experiences one or more outbursts in brightness nearly every year - is showing a tiny coma, still visible on Jan. 25, that looks like a miniature copy of 17P/Holmes in the days after its October outburst.

13 mag. dwarf nova in Canis Minoris

A recently discovered dwarf nova has been observed "during a ~4 h run from 2008 Jan 24.812 to 24.976, during which the average magnitude was 13.03 (CCD unfiltered). This showed 0.15 mag superhumps with a period of 0.0572 d," according to THE ASTRONOMER Electronic Circular No 2415 of 2008 Jan 26 12.20UT.

Friday, January 25, 2008

2007 TU24 already resolved by radar: it's double

Since two days ago the Goldstone radar is seeing the NEO, helping to refine its orbit (no Earth impact possible for hundreds of years) and vaguely resolving it into two objects.

Mercury: amateurs vs. MESSENGER

Some of the large-scale features on the hemisphere of Mercury that Mariner 10 missed but MESSENGER saw during its first flyby this month can also be imaged by amateurs. Let alone professionals using similar videoastronomical techniques.

Comet Holmes' coma could still be detectable one year from now

So calculates Richard Miles in The Astronomer 44 #525 [2008 January] 234: CCD cameras should be able to pick out a coma with some 4° diameter and a surface brightness roughly 3.5 mag. lower than now when Holmes is again in opposition around Dec. 2008/Jan. 2009. Amazing thought ...

Process your own New Horizons pix from the Jupiter system!

The original data from one year ago have now been released publicly - and allow for image processing experiments.

Thursday, January 24, 2008

Unusual approach of a (not too) big asteroid

Now JPL and NASA are reporting on the upcoming Earth flyby of NEO 2007 TU24 that has some less well-informed people worried. Should reach 10th magnitude in the night January 28/29!

(This blog has now been relaunched with a new name and language)