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Archive for September, 2011

Ever seen the Zodiacal Light ?

September 29, 2011 Leave a comment

No, me neither until this morning. I was reading Bob Kings excellent Astro Bob astronomical blog http://astrobob.areavoices.com/ and the entry for yesterday happened to discuss the autumn phenomena called the Zodiacal Light http://astrobob.areavoices.com/2011/09/28/comet-honda-visits-the-ghost-of-comets-past/  This faint, low,  roughly triangular glow of light, best seen in the east just before morning twilight, represents the reflected light from cosmic dust which has gathered on the ecliptic plane. The ecliptic plane is slightly tilted upward at this time of year which makes it more visible, particularly when the moon is absent. This interplanetary dust lies in a lens shaped band centered around the sun and extending out beyond Earth’s orbit. The dust is commonly thought to derive from the trail of comets passing through the solar system. I had a look this morning and there was certainly a very faint and high glow extending up at least 45 degrees into the sky when looking east around 6-6.30 am. I didn’t have the DSLR with me at the time but later on I thought I would have a look at the fisheye weather cams for the GRAS telescope in New Mexico and sure enough a faint triangular glow in the east was clearly discernible. Take a look at the image below and if you can see a faint wedge of light shooting up above the pole at the bottom of the image toward the Milky Way – that is the Zodiacal Light !

Categories: Comets, General

Massive Sunspot AR11302

September 27, 2011 Leave a comment

Sunspot AR11302 is a true behemoth at 150,000 km in length. It was crackling with B and C class flares today after calming down somewhat from its release of two X Class flares on the 22nd and 24th September. The spot is now facing Earth and if it releases any more high energy flares in the next couple of days we could see some spectacular aurorae down here around midnight in northern latitudes. Seeing conditions were extremely poor during imaging with a lot of atmospheric turbulence so these images don’t really do justice to the amount of finely structured features that were on view today.

80mm PST Mod Ha view:

CaK PST view:

80mm PST Mod Ha view with bright C Class flare activity in AR 11302:

 

Categories: Solar

The other Double Cluster – NGC 884 and NGC 957

September 26, 2011 1 comment

Most people are familiar with the spectacular view of the main Double Cluster located in Perseus which consists of the bright open clusters NGC 884 and 869 lying some 7300 light years distant. This jewelled duo shining at magnitudes 6.1 and 5.3 are easily  resolved in a moderate 3″ telescope, but binoculars will also provide a nice view and you can even see the cluster as a faint sparkling smudge of light with the naked eye on a clear night in a dark location. While images of this cluster can be found in every coffee table book and all over the web I thought it might be fun to try something a little different when I realised that the nearby NGC 957 would just fit into the view along with NGC 884, providing an alternate double cluster. For this image I used the GRAS20 Tak 106 FSQ in New Mexico which has a nice widefield view capable of comfortably framing both clusters. The image is a 600 sec unbinned one-shot colour exposure centred on RA: 02h 20m 59.0s DEC: 57° 09′ 30″ (J2000)

I wonder how many more images containing two or more open clusters found in our galaxy can actually be imaged in one frame ? Only one other springs immediately to mind for me and that is the M35/NGC 2158 combination in Gemini which I imaged back in 2008 with my Equinox ED80 and a Canon 350d DSLR (see below) . If you can think of any more do let me know via the blog !

NGC 957 (top left) and NGC 884 (right) :

Another double! M35 (bright blue stars) & NGC 2158 (tight yellowish white cluster bottom left):

Categories: Stars & Star Clusters

Comet C/2009 P1 Garradd

September 18, 2011 Leave a comment

I revisited Comet C/2009 P1 Garradd last night on its journey through the region between Aquila and Hercules courtesy of the GRAS G3 telescope (Takahashi TOA 150/SBIG ST 2000XCM) in New Mexico. This observatory has been plagued by cloud and rain for the last two weeks, but before the moon rose at 9.30 pm last night (NM time) the sky was gloriously clear so I took the opportunity to reserve some time on the one-shot colour camera. The image below is the result of just a 5 minute exposure and shows the coma and faint gas tail glowing the characteristic blue-green of cyanogens and diatomic carbon which are fluorescing in the sunlight. C/2009 P1 appears to be around magnitude 7.0 now and should continue to brighten slowly through to February 2012 when it will reach its peak magnitude of 6.0 and may become visible to the naked eye. The two bright stars on the right side of the image are HIP 91205 (top – mag 7.75) and HIP 91169 (bottom – mag 8.60). Image taken 17/9/2011  9.24pm (New Mexico time) RA: 18h 37m 13.0s DEC: 19° 52′ 17″ (J2000)

 

Categories: Comets

Comet 213P Van Ness now fading in Pisces

September 17, 2011 Leave a comment

Comet 213P Van Ness is passing high through Pisces at the moment and currently hovers at around magnitude 14.4. It will fade slowly through to the end of the year when it will be 16.5. During August and early September fragments of the nucleus were seen to break away, effectively forming three short-lived magnitude 20-21 child comets named 213P B,C and D. These fragments have faded dramatically now and may no longer exist. Below is a quick 5 minute exposure with the Spanish GRAS 07 17 ” planewave in rather poor light conditions with the moon about 60 degrees away to the south. The very faint tail (easily seen in August) extends to the top right. This is quite an interesting and rarely visited part of the sky with a number of very faint fuzzies in the wider original image that defy identification in my planetarium software, which only extends to magnitude 18. Loads of nice double stars in this area too! Image taken 1.02am 17/9/11 RA: 22h 49m 38.0s DEC: 04° 32′ 09″ (J2000)

And the negative image…..

Categories: Comets

M51 Whirlpool Galaxy Supernova 2011dh

September 10, 2011 Leave a comment

As I mentioned in my last post supernova 2011dh is still visible in the Whirlpool Galaxy (M51) with the aid of a telescope. Magnitude is currently around 14.8 and fading so there’s still time to catch this one. I used the GRAS G07 17″ Planewave to capture an image tonight, but even though the moon is 116 degrees away to the south there was significant moonglow and this created a pretty horrible gradient across the image which could not be edited out using the usual gradient and light pollution removal tools. I therefore turned the image negative and increased the contrast to bring out some detail. The supernova is clearly visible at the marked location.

Here’s the current AAVSO light curve for this supernova…….

Comet C/2010 G2 Hill and update on SN 2011fe in M101

September 9, 2011 Leave a comment

During the early morning of 7th and 8th September I attempted to image Comet C/2010 G2 Hill which is very faint at approx mag 11 close to Lynx. On both occasions there were significant guiding errors with GRAS G7 in Spain which produced some very odd star trails. The comet only reaches a sufficient height for imaging on the GRAS telescopes after about 6.00 am Spanish time when the comet reaches 40 degrees above the horizon, so there may be some early twilight effects at play here.  GRAS telescopes generally cannot image below 30-35 degrees and atmospheric aberrations will be high below this level anyway.

The image below has been significantly cleaned up with all of the star trails removed. C/2010 G2 Hill appears as a faint smudge in the centre with a small diffuse coma. The comet is currently slowly brightening and should be visible in telescopes well into next year. GRAS G7 – 600 sec Lum/Deep Space Planewave 17″/FLI ProLine PL11002M

The supernova SN 2011fe in M101 (Pinwheel Galaxy) seems to have reached its maximum magnitude at around 10.0 or 9.9 according to the light curve provided on AAVSO. If you are thinking of imaging the galaxy now would be the best time !  Don’t forget that supernova SN 2011dh is still visible for imaging in M51 (Whirlpool Galaxy) too, but you will need to catch M51 early after sunset as it dips below 30 degrees altitude and into the murk by 10pm in the northern hemisphere. The current magnitude of SN2011dh in M51 is around 14.8

AAVSO light curve for SN 2011fe 9/9/11