This new nova was discovered by Koichi Itagaki (Teppo-cho, Yamagata, Japan) on August 14th at a spectacularly bright magnitude 6.8 ! The nova appears to have brightened even more throughout today (15th) to a possible maximum magnitude of 5.7 – 5.5, which would make it naked eye visible and clearly visible in binoculars. As most novae rarely reach magnitudes greater than 12 this is a rare event. The nova is the bright star at the centre of the image below.
The spectrum of Nova Delphini 2013 suggests this is a classical nova ie. an interacting binary star system in which one star is a dense, hot white dwarf. Material from a cool, giant companion star falls onto the surface of the white dwarf, building up until it triggers a thermonuclear event. The drastic increase in brightness and an expanding shell of debris is the result. Classical novae do not result in an entirely destroyed star, but are instead believed to recur when the flow of material onto the white dwarf resumes and produces another outburst. The speed of material being ejected from this supernova has been calculated at around 1,500 miles per second. The progenitor star may have been around 17th magnitude prior to the outburst.
UPDATE 1 16th August – AAVSO observers are now reporting the magnitude of this nova at around 4.4 – 4.5 This will be readily visible to the naked eye although the moon is currently affecting visibility.
UPDATE 2 17th August 12.30am – Just had a look now and it is very easy to find with the naked eye even though there is low moonlight and cloud around. The constellation Sagitta neatly points the way to it. It looks about magnitude 4.8 to me visually when compared with the nearby star HIP 101867. This seems to match current AAVSO observations which show the nova has started to fade back from a peak 4.5 to mag 4.8
UPDATE 3 18th August – According to AAVSO observer reports the magnitude of the nova appears to have stabilized around mag 5.0 (updated chart below) for now. The peak magnitude of 4.3 was reached on the 16th 16.45 UT. A fast decline was predicted thereafter of about 1 magnitude per day, but this prediction has now been revised. The progenitor star appears to have been mag 16.9 before the outburst.
There are some useful finder charts here for visual observing http://www.virtualtelescope.eu/wordpress/wp-content/uploads/2013/08/NOvaDel2013_map.jpg and here http://www.virtualtelescope.eu/wordpress/wp-content/uploads/2013/08/NovaDel2013_map2.jpg
Image taken 15/8/13 11.43 pm local time on T18 (12.5″ Planewave CDK, KAF-6303E) at Nerpio, Spain. 1 x 60 secs Lum. Processed in Maxim DL5, Photoshop CS2. RA: 20h 23m 30.0s DEC: 20° 46′ 06″ (J2000)
Click image to enlarge:
AAVSO Light Curve:
Supernova 2013ct is a Type Ia discovered by Stu Parker (BOSS – New Zealand) on 10/5/13 when it was at it’s peak magnitude of around 12.2. It has now faded to approx mag 15.4
NGC 428 lies in the constellation Cetus approx. 37 million light years away. The galaxy has a distorted shape perhaps resulting from the collision of two galaxies.
Image taken 12/8/13 4.46 am local observatory time at Nerpio, Spain using remote iTelescope T07 (Planewave 17″ CDK, SBIG STL-11000M ABG). 4 x 300 secs Lum. Processed in Maxim DL5, Adobe Photoshop CS2, DeepSkyStacker 3.3.2
Click image to enlarge:
AAVSO Light Curve:
This Type Ia supernova was discovered on 10/7/13 by the Lick Observatory Supernova Search programme and Kuniaki Goto two weeks before it reached it’s peak brightness of around magnitude 12.7 on 25/7/13. The supernova is currently at magnitude 13.0
NGC 7250 (PGC 68535) lies some 55 million light years away and is a rather small object which is difficult to image. It was discovered by William Herschel on November 8th 1790 and is classed as a starburst galaxy.
Image taken 6/8/13 4.18 am local observatory time at Nerpio, Spain using remote iTelescope T07 (Planewave 17″ CDK, SBIG STL-11000M ABG). 4 x 300 secs Lum. Processed in Maxim DL5, Adobe Photoshop CS2, DeepSkyStacker 3.3.2 RA 22 18 17.7, Dec +40 33 47
Click image to enlarge:
AAVSO Light Curve:
A new Type IIP supernova was discovered in spiral galaxy M74 in the constellation Pisces by the Lick Observatory Supernova Search on 25th July. It has brightened rapidly to around magnitude 12.4 and is visible in 8″ amateur telescopes, but will show up readily in images taken on lower aperture telescopes of 4-6″ under dark and clear skies.
This star was originally a supergiant about 8x the size of the sun before it ran out of fuel to burn, collapsed due to gravitational forces and then exploded into the bright source of light that we can now see. Besides blasting new heavy elements out into space the supernova may leave behind a neutron star, which is the compressed remnant of the stars original core.
Image taken 4/8/13 4.01am local observatory time at Nerpio, Spain using remote iTelescope T07 (Planewave 17″ CDK, SBIG STL-11000M ABG). 5 x 300 secs Lum. Processed in Maxim DL5, Adobe Photoshop CS2, DeepSkyStacker 3.3.2
AAVSO Light Curve:
On May 17th the automated Lick Supernova Search discovered the SN 2012cg supernova in galaxy NGC 4424 in the constellation Virgo. From 18th magnitude it has now brightened to 12.0 and rivals the core of the galaxy for brightness. This exploding star was originally a White Dwarf star equivalent in mass to our own Sun and locked in a binary orbit with a much larger star. It steadily drew matter from this companion star up to a point where it became unstable, collapsed in on itself and exploded, producing what is known as a Type Ia supernova. This spectacular event should be visible in telescopes of 6″ diameter and above.
Image taken Sunday June 11th 00.59 am from Nerpio, Spain with iTelescope T7 Planewave 17″ CDK, SBIG STL-11000M. 300 sec Bin 2. RA: 12h 27m 11.9s DEC: 09° 25′ 01″ (J2000)
Supernova SN 2012aw is a Type IIP and clearly visible in galaxy M95 in the constellation Leo at magnitude 12.7. It was discovered by The Italian Supernovae Search Project on 16/3/2012 and has rapidly brightened from its discovery magnitude of 15. The original star is thought to have been a red supergiant about 8 times more massive than the sun. This star used up all of its nuclear fuel then collapsed in on itself under intense gravitational forces and at speeds approaching 45,00 miles per second. When the outer layers smashed into the core they crushed it and this sent a massive shock wave back out towards the surface, tearing the star apart in the process and creating the bright supernova that we see. The supernova appears to have reached its maximum brightness now and will probably fade over the coming weeks. It can easily be seen in telescopes of 4″ and greater diameters from good observing locations. Image taken 25/3/12 8.55 local time via iTelescope.net T07 in Nerpio, Spain. Planewave 17″ CDK, SBIG STL-11000M, 3 x 300 sec Bin 1. RA: 10h 43m 59.9s DEC: 11° 42′ 00″ (J2000)
The Type II supernova 2012A was first recognised by Bob Moore, Jack Newton, and Tim Puckett during an automated search on January 7th using a 16″ reflector when its magnitude was estimated at 14.6. This is the first supernova of 2012 and it is located in the irregular galaxy NGC 3239 (Arp 263) in the constellation Leo. The galaxy has an apparently chaotic shape which is the result of two galaxies colliding and merging. By January 27th the supernova had increased in brightness to 13.4 mag and has now faded back to around mag 14.4 in the above image. The light from this supernova has taken 25 million years to reach us !
The AAVSO light curve for SN 2012A is shown below……
Image taken 9.24 pm 28/2/12 at Nerpio, Spain (UTC+1) on T7 (Planewave 17″ CDK Dall-Kirkham Astrograph,SBIG STL-11000M) RA: 10h 25m 05.9s DEC: 17° 10′ 01″ (J2000) 25 minutes exposure. Bin 1 @ 2 x 600 and 1 x 300 seconds.
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…….
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
So last nights attempt to capture remote images of the supernova in M101 and Comet C/2009 P1 Garradd proved completely abortive! GRAS in New Mexico was completely clouded out all night and so was Spain until early morning. Having stayed up until 3.30am to make sure I caught M101 before it got too low in the sky I figured I would switch to the Spanish telescopes where Stellarium was telling me that M101 was visible around 4am. This proved to be incorrect due to a glitch with the timezone settings in Stellarium and the telescopes could not find the object – so I had nothing to show for a sleepless night !
Tonight was an altogether different scenario. I double checked where I had gone wrong with Stellarium and corrected the error. It showed I had a narrow window of opportunity between 8.00 and 8.45pm where I could image M101 before it dipped below the critical 40 degrees in azimuth where the telescopes in Spain cannot image due to the height of the surrounding walls in the observatory. The observatory went live around 8.15 pm so I logged onto the GRAS 7 telescope which is a Planewave 17″ imaging with an FLI ProLine PL11002M camera and set up for 15 mins of Luminance, bin 1, in 300 and 600 second exposures. At the same time I logged onto GRAS 16 and imaged C/2009 P1 for 10 minutes using the Takahashi TOA 150mm refractor and SBIG STL11000M camera. The moon was up at the time, but I was imaging away from the main area of moonglow (GRAS recommend imaging objects at least 60 degrees away from the moon) so I guessed everything would be OK – and it was !
Considering these images are just 10 minutes exposure I was pretty blown away by the results !! There’s a nice tail extension on the comet and the supernova is clearly visible in M101 as a 10.5 magnitude (now 9.9 September 6th ! ) exploding star which is now easily rivalling the galactic core in brightness. I’m used to processing Jpeg and Tiff files from the DSLR for astro images so the FITS files that you download from the GRAS server were a bit of a mystery to me. I downloaded the FITS liberator software and read the manual then got stuck in with the initial processing and saved the results as Tiff files. I was totally amazed at the quality of the images when I opened them up in photoshop for a bit more tweaking – nice clean images with hardly any signal noise. OK so i’m now officially hooked on remote telescope imaging
Anyway – here are tonights images greatly reduced in size (and quality) from the Tiff originals
M101 Pinwheel Galaxy and Supernova 2011fe which is marked by the arrow
Comet C/2009 P1 Garradd