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Reflections on a night with the Perseid Meteor Shower 2013

August 18, 2013 Leave a comment

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Photo courtesy of Rod Trevaskus from Middletown in Powys who took this image of the Milky Way on the 12th August, complete with two meteors! Click to enlarge…

Last Monday night (12th August) was the peak of the Perseid meteor shower when the dust trail left over from the passage of Comet Swift-Tuttle crosses Earth’s orbit and the debris, reaching speeds of up to 132,000 mph,  burns up in our atmosphere. It is the most impressive of the annual meteor showers with the highest number of bright fireballs (meteors reaching a brightness of magnitude -3 or brighter at the zenith) and at it’s peak, in good dark-sky conditions, you can expect to see up to 120 meteors per hour across the whole sky.

We had almost forgotten the shower here in the early evening as the weather had been very cloudy, there was a low quarter phase moon in the west and the prospects for good visibility looked poor. The inclement weather, combined with the need to get up early for work the next day, made us rather apathetic about the whole event. Fortunately my wife poked her head out the back door just before we headed off to bed and I heard that familiar little gasp of awe as she called me out to look at the amazing clear sky.  The clarity of the sky on Monday night was astounding here, one of those really rare nights when the stars are rock steady with no furious twinkling going on. The Milky Way was so bright overhead that it looked like moonlit cloud passing over. Within a minute we had seen our first small Perseid flash by and decided to stay out for a while. The Ikea Poang chairs were brought out, which lend themselves perfectly to visual astronomy as they are low and gently reclined with good back and neck support. We covered up in light duvet jackets and a fleece or sleeping bag over the legs – we were all set for the show.

In the end we were out there for just over two and half hours from 10.30 -1.10 with a good dark view of the western sky and saw a total of 60 meteors. Most were faint and white with a yellowish tinge, but some were greenish and one large fireball heading down through the constellation Hercules was quite magenta in colour, with a long persistent glowing tail burnt onto our retina’s which lasted a few seconds. We had a nice bright pass of the International Space Station around 11pm and there were two really bright iridium flares from the Iridium telecoms satellites passing over. We had at least three bright fireballs in that time and something really big flashed over in the north, out of our direct line of view, which briefly lit up the thin cloud cover building up at that time. We both came in buzzing from everything we had seen and that excitement lasted right through to the next day.

With all of our expensive modern equipment in amateur astronomy these days it is comforting to know that the simplest and most companionable form of visual astronomy can still give you that sense of wonder and buzz of excitement. It was one of those unplanned events in our life that we will always remember and cherish.

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Categories: Meteors

Bright NOVA Delphini 2013 in Delphinus !

August 16, 2013 Leave a comment

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:

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AAVSO Light Curve:

Nova Del 2013 AAVSO 18-08-13

Categories: Supernovae

Supernova SN 2013ct in galaxy NGC 428

August 13, 2013 Leave a comment

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:

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AAVSO Light Curve:

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Supernova SN 2013dy in galaxy NGC 7250

August 6, 2013 Leave a comment

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:

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AAVSO Light Curve:

Light Curve

Supernova SN 2013ej in galaxy M74

August 4, 2013 Leave a comment

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

M74-2013ej-1024x

AAVSO Light Curve:

M74-2013ej-AAVSO-light-curv