Two ‘bright’ supernovae in nearby galaxies are well within the range of most amateur astronomers telescopes.

Supernova Candidate PSN J10435372+1140177 in M95 – now designated 2012aw

Supernova 2012aw imaged by Nick James on March 18th

This supernova was discovered on 2012 March 16.8493 by J. Skvarc & Alessandro Dimai of the Italian Supernovae Search Project.

M95 is at R.A. = 10h43m53s.72, Decl. = +11°40′17″.7 (= NGC 3351) and the SN is located 60″ west and 115″ south of the center of M95. M95 is well placed for observation, transiting at around 23:00 UT, with the galaxy culminating at about 50° altitude.  M95 is part of the Leo I group of galaxies, about 38 million light years distant.

A discovery image can be found here:
www.observatorij.org/vstars/PSN20120317/PSNJ10435372+1140177.jpg

Nick James observation of this object (above) puts it at about magnitude 13 and adds that unfortunately Mars is very close and has caused significant interference with the image.  However, Mars will continue to move further away as time progresses.

And here is an image by Martin Mobberley, the following night:

Supernova 2012aw imaged by Martin Mobberley on March 19th

SN 2012au in NGC 4790 in Virgo

Discovered by the Catalina Real-Time Transient Survey and Stan Howerton (USA) at mag 18.2C on 2012 March 14.450 but it has rapidly brightened and is currently at magnitude 13.25V.   This SN is of Type Ib, and apparently found in the early stages of its evolution so it may well brighten further.

However, it is vary close to the core of the host galaxy, but is the brightest supernova so far this year. Recent images etc can be found here: www.flickr.com/photos/watchingthesky/6846911246

NGC 4790 is at R.A. = 12h54m52s.18, Decl. = -10°14′50″.2 and the SN is located 3″.5 east and 2″.0 north of the center of NGC 4790. NGC 4790 is not very far from Saturn, but currently culminates at about 27° altitude at around 01:00 UT.

Further information on these and other supernovae can be found on the extensive web page of the International Supernova Network and the Astronomy Section of the Rochester Academy of Sciences at:
www.rochesterastronomy.org/supernova.html.

This meeting will be held at the Humfrey Rooms, 10 Castillian Terrace, Northampton, NN1 1LD

There has been a slight change to the previously advertised programme as due to illness Martin Lunn is unable to give his talk on dating Cassiopeia A. However David Boyd and Owen Brazell have kindly stepped in at short notice to give talks and the (hopefully) final programme is shown below.

09.30 Coffee
10.00 – 10.45 Welcome and Review of the Year – Stewart Moore
10.45 – 11.30 The Death of Stars – Bob Winter
11.30 – 12.15 The Spectra of Dying Stars – Robin Leadbeater
12.15 – 12.30 Behaviour of Gyulbudaghian’s Nebula and PV Cep – David Boyd
12.30 – 12.45 New Planetary Nebulae – Owen Brazell

12.45 Buffet Lunch

14.30 – 15.15 Building and Using a Large Dobsonian – Andrew Robertson
15.15 – 16.00 Observing from New Mexico Skies – Chris Longthorn

16.00 Tea

16.30 – 17.30 Cosmic Genesis – a Unique View of the Birth of a Neutron Star – Dr Matthew Malek (Imperial College)
17.30 Meeting round up – Stewart Moore

Everyone welcome. Entrance £10 (to include buffet lunch) payable at the door.

No need to book in advance. All talks subject to possible change.

Exhibition of deep sky material by Section members is encouraged (bring your own display boards).

The BAA and Webb Deep Sky Society hope to have sales stands at the meeting.

Over the next few nights comet C/2009 P1 Garradd will pass close by the globular cluster M92, in Hercules, and this will make for an interesting observing opportunity.

Comet 2009 P1 Garrad on 31st January 2012 by Martin Mobberley

Stewart Moore, the BAA Deep Sky Section Director writes:

Although not a spectacular comet with a majestic tail, C/2009 P1 (Garradd) has endeared itself to many observers by visiting bright deep sky objects on its journey through the heavens.  In late August 2011 it visited the globular cluster M71 and in early September of the same year it made a close approach to the Coathanger asterism.  Now visible in the morning sky, Garradd continues its friendship with deep sky objects by making a close approach to another globular cluster, this time M92 in Hercules.

On February 3/4 it passes within 0.5 degree west of M92, making an ideal photo opportunity. The coordinates of M92 are RA 17h 17m.1 and Dec +43deg 08min.  M92 has a visual magnitude of 6.5 and a diameter of 14 arcmin.  Details and an ephemeris for the comet, which has a predicted magnitude of 6.5, can be downloaded from the Comet Section web page and are also available in the latest BAA paper circular No. 826 dated 2012 January 18.

With the Moon setting just after 04:00 on Feb. 3, M92 and the comet will be found at an altitude of around 40 degree in the east.  Please send all observations to both the Deep Sky Section and the Comet Section.

As Comet Garradd makes its lazy sweep across the night sky, after last weeks close encounter with M71, this week the comet will cross just under the popular asterism known as the Coathanger. Also known as Brocchi’s Cluster and catalogued as Collinder 399 – today, though, it is generally recognised to be just an asterism, a chance collection of stars making up a pattern, rather than a true cluster of stars that were created at much the same time.

The Coathanger also has a special place in the heart of the BAA, as one of the Association’s most active observers, George Alcock, discovered a nova there in 1976.

This chart shows the comets path over the next few days.

This comet is easy with 10×50 binoculars, and is straightforward to find by locating the lovely double star Albireo (Beta Cygni), then hang down south and you will come to the Coathanger, and just under the Coathanger will be found comet Garradd.

If you manage to capture an image of this, please send it in for our picture of the week spot.

The Palomar Transient Factory (PTF) discovered a supernova in M101 on August 24th. At magnitude 17.2 it was pretty faint, but as this supernova was discovered ‘on the rise’ it has been steadily brightening, and may reach mag. 10 or 11 – making it easily visible in binoculars or a small telescope.

Image of supernova PTF11kly in M101 by BAA Member Denis Buczyski

Although M101 is in the circumpolar constellation of Ursa Major, and so will never set from UK locations, it does not attain a very high altitude, and will be best placed for observation as soon as the sky becomes dark.

The observations of supernovae are important, because they are a key component of the distance ladder. This is a series of stepping stone techniques used to measure distances to far-off galaxies. It is thought that type Ia supernovae explode with much the same brightness due to the physical nature of the star, so finding a supernova relatively close-by helps our understanding of the physics of the explosion, and further help the calibration of the distance scale.

Amateur astronomers can best contribute to the science by measuring the brightness of the supernova, and contribute to it’s light curve.

But there is also a great pleasure in seeing for yourself one of the greatest cosmic events, which happened 23 million years ago and the light of the event has just reached us.

Over the next few nights the comet C/2009 P1 Garradd makes a close pass by of Messier object 71 in the constellation of Sagitta (the arrow). Close encounters between different classes of astronomical object are always of interest, both for the visual observer and the astronomical imager.

This chart shows the position of the comet and M71 in Sagitta around 22:30UT on August 26 2011.

Stewart Moore, director of the BAA Deep Sky Section writes:

M71 is a very loose globular which is close to us and lacks the condensed core of some of the more familiar summer globulars. In small binoculars or telescopes it appears as a mag 8 misty patch around 6 arcmin diameter and looking very comet like in appearance.  It is easy to locate as it lies in Sagitta between and slightly south of a line from mag 3.5 gamma (the bright star forming the point of the arrow shape) and mag 3.8 delta just under 3 degree to the west. The position of M71 is RA 19h 54m 19s and Dec +18deg 49min (2000).

An ephemeris for Garradd can be found on the BAA Comet Section web page but for the night of August 26 / 27 is given as 19h 53.7m and Dec +18.57deg (2000)

On Aug 24 / 25 under mag 5 skies both comet and cluster were easily visible together in hand held 10×50 binoculars, both appearing similar in magnitude and in size. In 15×70 binoculars (4 deg field) the cluster appeared round with the comet diffuse and fan shaped.

Nick James reports there are at least two ‘bright’ novae in M31 at the moment. Though  at around 17th magnitude both are easily within the reach of amateur astronomers with CCD cameras.

These two novae exploded in the Andromeda Galaxy some 2.5 million years ago but their photons have only just arrived at the Earth where they were first detected on August 4. Some of these photons were captured via telescopes and CCD cameras in Chelmsford to create this montage.

M31 Novae on 20110804 - Nick James

These objects are just like the novae in our galaxy but they a lot further away and so they appear much fainter. A nova is a close binary star system where the primary white dwarf star pulls material off its companion. The material spirals down onto the white dwarf and eventually enough accumulates to cause a runaway nuclear fusion reaction. This dramatically increases the brightness of the system by 10 magnitudes or more.

Most novae have an absolute magnitude of between -7 and -9 at the peak of their outburst (The absolute magnitude is the magnitude the nova would have if it were 10 parsecs, or 32.6 lightyears, away). M31 is around 2.5 million light-years away and so its novae have an apparent magnitude at peak of around 16 to 18 as seen from our vantage point. These latest novae fall right in the middle of that range at around magnitude 17. In fact, if the lightcurve of the nova is carefully measured it can be used as a “standard candle” to give us an idea of its distance.

Many BAA members have been able to view and image this bright supernova which was recently discovered. For more info about the SN see this blog post

Here are a few of their images…

Continue reading »

Guy Hurst, UK Nova / Supernova Patrol and Supernova Search Coordinator for the BAA Deep Sky Section, today issued a TA Circular (E2743) giving details of a new supernova discovery in M51.

The object is located at: RA 13h 30m 05.8s and Dec +47deg 10min  11.2sec (2000). The magnitude of SN is currently around 13.5 putting it within easy range of imagers and visual observers with medium to large aperture telescopes.

An image of the galaxy taken by Ron Arbour, with the SN marked is below.

Supernova in M51 - Ron Arbour

Sadr, Butterfly and Crescent Nebulae - Bob Winter

Imaged from a London rooftop, the Sadr, Butterfly and Crescent Nebulae in Cygnus taken on 25th May 2011.

Splendid aurora observed on 15th March

Comet Garradd close to M92

Spectacular aurorae seen in the last week