Over the past few days the weather across the UK has been patchy but many people have been able to see this comet and we have received some excellent images. Even though the comet is fading it is becoming easier to see as it moves higher into the western sky. A chart showing its position an hour after sunset is included in this Journal article.
The comet is now high enough that it can be seen or imaged in a darker sky. This allows stars to be included in the images so it is possible to estimate the comet’s magnitude. Using a V filter Richard Miles estimated the magnitude as +0.8 on the evening of March 14 so it probably didn’t quite reach mag zero at perihelion but it wasn’t that far away from some of the more reasonable predictions from earlier in the year.
2013 March 17. 80mm ED Apo + Canon 1000D, 10s at ISO1600, Denis Buczynski
The widefield view in the twilight is still impressive and the comet’s broad dust tail is clearly visible in binoculars. Many people have now reported that the comet is an easy naked eye object if you know where to look.
2013 March 17. 1905UT. Canon 500D at ISO800. 60mm lens. Damian Peach.
The view from space is even more impressive. The comet has been visible in the STEREO-B Heliospheric Imager. This is a camera which takes 20×20 degree images of the space between the Sun and the Earth. In these images the comet has a spectacular dust tail which shows much structure. We can’t see most of this from the ground at the moment but some observers are picking up hints of it. Michael Jäger has probably obtained the best result so far as you can see in this amazing picture.
2012 March 12, 2329 UT. STEREO-B HI image. 1200s exposure, unsharp masked. The bright object top right is the Earth.
Denis Buczynski has uploaded many of the images to the Comet Section gallery. Please keep sending your observations to cometobs@britastro.org but please could imagers follow the instructions here. Images should have names like 2011l4_20130317_1904_dgb.jpg. We receive lots of images with names like panstars.jpg and these will need to be renamed to the correct format. This requires a lot of work, particularly when we receive dozens of images a day.
Keep watching this comet. You never know what it will do next.
The minor planet Ceres, currently at magnitude 8.3 comes within 0.4 degrees of the 2nd magnitude star beta Tauri (El Nath) on March 6. This is an ideal opportunity to find Ceres with binoculars. El Nath is easy to find (it is the star marking the northern horn of Taurus) and Ceres will be passing just south of it over the next few days. The image shows Ceres tonight (March 4th) with El Nath at the top left. Click on the image to get an animation of 23 x 2 minute frames (around 48 mins real time) and see if you can spot the slight motion of Ceres relative to the background stars. The field of view of this image is around 0.7 deg square, N up.
Thanks to Mike Harlow for alerting me to this appulse.
Weather permitting we are going to try to do a live webcast of the 2012 DA14 close approach tonight. This will consist of periodically updated live images from a small telescope with a field of view of around 1 degree. We’ve not had much time to test this so it may or may not work for various reasons but you might like to keep an eye on the following page:
http://britastro.org/live/page.htm
If the weather cooperates the first live images should appear around 20:10 as the object rises above my local horizon. At that time it will be around magnitude 7.5 and moving at around 41 arcsec/sec.
19:15 – Currently the sky here in Chelmsford is totally cloud covered and so the live webcast is unlikely to show much early on. The forecast for later this evening is a bit better.
20:15 – 2012 DA14 is now clear of my horizon obstructions but it is still cloudy here. It may clear later.
22:10 – Still cloudy in Essex but Denis Buczynski has obtained a nice image from Tarbatness.
2012 DA14 from NE Scotland
Unfortunately, the sky never cleared in Chelmsford so we had nothing to show during the webcast. We’ll try again in the future when another interesting astronomical event takes place.
Presidential Portrait of Sir Patrick Moore from 1984
It is with the deepest sadness that I report the death just before 12.30 today of Sir Patrick Moore.
Patrick has long been an inspiration and guide for so many BAA members. He served as the Association’s President from 1982-1984, as well as directing with energy and distinction both the Mercury & Venus Section and the Lunar Section. Indeed, he performed the latter role on two occasions, from 1964-1968 and from 1971-1976. In recent years he has been an honorary Vice-President, and although he has been unable to attend our meetings, he has continued to take an active interest in the affairs of the Association that he first joined in December 1934 at the age of 11. He made a point of visiting the BAA stand at Astrofest 2012, despite not being in the best of health.
There can be few BAA members who do not owe their interest in astronomy to the influence of Patrick, either through his numerous publications or his monthly “Sky at Night” television programme. His enthusiasm was deeply infectious, and what he had to say was truly inspirational. Many of us benefited from personal contact with him – the time and energy he devoted to correspondence with all who wrote to him was quite amazing, and his hospitality at Farthings legendary.
Patrick’s passing was peaceful, at home in Selsey, where he was surrounded by those closest to him. Many of us felt that this day could never come, and that the normal laws of nature would somehow be suspended in this case. Sadly and inevitably, that was not be be, and we shall all miss a presence that has enriched British astronomy, and the lives of most of us, for as long as we can remember.
In due course we shall have occasion to pay full and proper tribute to the man and his achievements. The grief we feel at this moment is bitter, but Patrick’s legacy is immense – and that is something from which we shall all continue to benefit in the future.
Bill Leatherbarrow
President
Our analysis of the fireball continues. In the light of current speculation we provide the following information based on our early results.
Currently, our first pair of images of the object are from southern Norway when the fireball was high over the North Sea. We have used an accurately timed shutter gap to determine that the velocity at this point was 12.0 km/s and the height was around 60km descending. This velocity is in excess of Earth’s escape velocity and so rules out a man-made satellite re-entry. Therefore, it is most probable that this object was natural and that atmospheric entry was well to the east of our first images.
In this regard we would be very interested to hear from observers in Denmark, north-eastern Germany, southern Sweden and northern Poland who witnessed the fireball at 23:55 CEST on Friday 21 September. Please contact us at meteor@britastro.org.
We have used the known exposure duration of an image from the west coast of Ireland to estimate the velocity of the two brightest components as they moved out over the Atlantic. We get velocities of 7.8 and 8.5 km/s and a height of 62 km ascending. These velocities and the track orientation and position are not at all consistent with ongoing speculation that there is a connection between this fireball and a fireball seen in south-eastern Canada/north-eastern USA 155 minutes later.
Further information will be posted as it becomes available.
John Mason & Nick James.
A preliminary analysis of the fireball track based on detailed analysis of photographs submitted to the BAA Meteor Section and collected by John Mason is shown in the attached picture. This is based on an analysis by Nick James. We are very grateful to the photographers who have provided their images and associated data. Further investigation is underway to accurately determine the height and velocity at various points along the track based on the known exposure times of photographs.
If you have not yet submitted your observations of this event please send them as soon as possible to the Director of the Meteor Section at docjohn@dircon.co.uk or meteor@britastro.org.
Image coverage of the track
Zoom of the track over Ireland
This text is taken from BAA e-bulletin 698 written by John Mason.
Hundreds of eyewitness reports are coming in of a brilliant fragmenting fireball, visible at about 22:55 BST (21:55 UT) on Friday, 21st September 2012. This is clearly one of the most dramatic events reported to the BAA Meteor Section in recent years. On Friday evening, there was scattered and more continuous cloud cover over much of South-East England, but the rest of the UK and Ireland were largely very clear, with transparent starry skies. This, coupled with the fact that many people were out on a Friday evening and the truly spectacular nature of the fireball itself, are clearly the main factors in it being reported by so many thousands of people over such a very wide area. This extends northwards and westwards from a line roughly linking Norfolk in the East to Devon in the South-West, with the majority of sightings so far received coming from Wales, the North-West, Central and North of England, Scotland and much of Ireland. When first seen the fireball appeared as a single very brilliant object but it then fragmented into a very large number of bright secondary fireballs, all travelling along roughly parallel paths across the sky. One highly unusual feature of this fireball is the length of time for which it was visible due to its apparent very slow speed of movement across the sky. This has led some people to speculate that the fireball was due to the re-entry of a large fragment of space debris. However, there are several aspects of the event, at this very early phase of the investigation, that do not appear to fit with this hypothesis and it would be unwise to rule out other possibilities at this stage. The undersigned has received many reports of the fireball, but these extracts from the following two more detailed accounts (which have, of necessity, been shortened here) give a very good general idea of the nature of this most unusual event. From David Stewart, Observing Coordinator of the Irish Astronomical Association (IAA), observing from Delamont Country Park, one mile south of Killyleagh in County Down. "At 22:54 BST, a group of 12 IAA members spotted an amazing group of fireballs rising from trees at the eastern horizon to the right of Jupiter as seen from the main car park. It was immediately thought they might be fireworks but they continued to rise at a steady pace and fan out slightly as they approached us from distance with their numbers increasing and their brilliant intensity remaining unchanged. We estimated approximately 20-30 fireballs were seen following the same east to west trajectory each with an estimated brightness between mag. -5 to -7 and each left a medium trail as they travelled almost directly overhead. No noise was heard except for the excited astronomers. A larger group of 4 or 5 fireballs were at the front of the group and differences in size were apparent but each burned with a similar brightness and a distinct orange hue. We were able to observe the fireballs for 2mins from the trees in the east to the trees in western horizon and we had particularly good views in that direction. As the fireballs approached the western horizon their numbers dwindled, possibly due to burning up and atmospheric extinction, at least 2 or 3 were seen disappearing behind trees. They were travelling at a speed somewhat faster than the ISS but not as fast as a typical meteorite on entry into the Earth's atmosphere." And from Paul Buglass, reporting on behalf of 10+ members of the York Astronomical Society (YAS) who were observing at the YAS Observatory, 4 miles west of York. Conditions were totally clear, and a very transparent night. "At approximately 10:56ish (BST), a group of us were talking outside and I noticed a very bright light low down over York (due East) . very bright with a slight green tint.. It seemed to be moving very slowly, flickering slightly, and at first I thought it was a low flying aircraft . then I thought perhaps it was a helicopter. It still hadn't moved much, but as the seconds ticked by it slowly started to show more movement to the left and slightly gain elevation .As its angular velocity increased, the bright green light started to show a slight tail as it passed through the bottom of Auriga, and then as its apparent angular speed increased more, a longer trail of darker red/orange trail formed, with bits coming off, as it approached the Plough. It then started to lose more distinct fragments downstream, with a orange almost ember like appearance, then the main bright white/green head puffed explosively and lost many more orange fragments which trailed off downstream as it passed through the Plough.. It continued West in a very flat trajectory, gradually losing the bright head as it moved to the West, and . faded to about 6 or 7 glowing orange points . The direction it was finally lost from view was directly under Hercules.. Total observation time was possibly 60+ seconds from first sighting low in the East to fading from view in the West." Most of the reports received so far are either quite brief or contain a lot of descriptive information about the fireball's changing visual appearance, BUT we urgently need more positional information relating to the fireball's trajectory across the night sky. Photographs which show background stars, and even video clips or still images from mobile phones could prove very useful in this regard. PLEASE could local society secretaries or other officers who receive this e-bulletin circulate it to all of their members and any other interested parties. Clearly this was a very major fireball event and any BAA members who saw it, or who may have been contacted by non-astronomers who witnessed it, are asked to collect as much information about the sighting as possible and send it either to the Meteor Section Director at docjohn@dircon.co.uk or to meteor@britastro.org. Useful information will include the name and location of the observer, the precise time of the event, the altitude and azimuth of the start and end points of the visible track, the position of the observed track against the background stars, and a description of the fireball's visual appearance, colour, etc. together with any unusual features. This e-bulletin issued by: John W. Mason, Director, BAA Meteor Section 2012 September 22
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:
http://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: http://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:
http://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.
As part of our near-term strategy to significantly increase the BAA’s online presence, Council has decided to ask for expressions of interest from a suitably qualified person to take up a freelance web designer role. This person would be responsible for a radical overhaul of the Association’s website using open-source tools, the management and maintenance of our online presence and the commissioning and management of content.
Council envisages offering a 3-year contract, reviewed annually for a fee in the region of £12-14K per year. We would expect the necessary commitment to average around 15-20 hours per week although workload will be variable.
The successful applicant will have a large amount of autonomy to work towards the goals set by Council and we would expect this activity to start sometime in the 2nd quarter of 2012. Membership of the BAA is not essential but a good knowledge of amateur astronomy, the Association and its objectives will be expected.
To express an interest in this exciting opportunity and to receive further details please send an e-mail to webdesign@britastro.org before Friday, 10th February.
@britastro 