The BAA would like to extend our warmest congratulations to Bob Mizon, co-ordinator of the BAA’s Campaign for Dark Skies who has been awarded an MBE in the Queen’s Birthday Honours List “For voluntary service to Astronomy and to the Environment”.
Bob has been a tireless campaigner for protection of the night time environment and against the excesses of light pollution for many years and this recognition of his efforts is very well deserved.
Well done Bob!
The BAA Aurora Section encourages the observation of the aurora, the recruitment and training of observers, the collection, analysis and reporting on the occurrences of auroral events. The present observer network comprises members of the BAA or other astronomical societies, individual observers, professional meteorologists and ships’ officers at sea. Observations are collected from Canada, the United States, Iceland, The British Isles and European countries. The co-ordination of observing in the Southern Hemisphere is carried out by the Royal New Zealand Astronomical Society Aurora Section. There is very close co-operation between the two Sections and details of observations are exchanged.
Aurora, Pete Urwin, Scotland
Our Section investigates the behaviour of the mid latitude storm aurora as the polar auroral oval expands during active conditions. On the other hand one of our members has spent a number of holidays in January on the island of Spitsbergen to observe and study the polar aurora, the dayside aurora and the theta aurora that can only be observed over the 24 hour sunless Arctic night. The original reports as received from observers are placed in the archives of Aberdeen University, Scotland and the details thereof are the subject of annual reports and technical papers published in the BAA Journal and in the “Marine Observer” as published by the British Meteorological Office.
The Section also observes the noctilucent clouds that are visible in the period May – August in the northern hemisphere, only as a summer phenomenon. The clouds appear at a height of about 80 kilometres and are visible when the sun is between 6 and 16 degrees below the horizon. The techniques to observe the clouds are identical to those used with the aurora hence Section members are well placed to make observations for the assistance of upper atmosphere scientists, who have asked us for our assistance. In this instance there exists a Canadian network of observers. There is also a good network of observers in Finland.
Aurora alerts by text, phone and email are available from Spaceweather.com
NGC 6356 by Dave Holt
One of the ’summer globulars’ – NGC 6356 in Ophiuchus is not the brightest of ‘globs’ at magnitude 8.4, but is nicely formed.
Dale made this sketch using his 505mm newtonian telescope with a Watec 120N video camera, and then sketching from the screen.
This great full disk image of the sun was taken by Pete Lawrence in Selsey on the 11th June 2010 in Hydrogen Alpha. The image shows 2 bright areas on the disk towards the left (west) which are sunspot groups AR1080 (south) and AR1081 (north). The image also shows prominences on the limb and ejecta of superheated plasma rising away from the NW limb (uppper right of the disk). The darker marks on the disk are filaments which are prominences seen against the solar disk as oppossed to the limb, hence they appear dark rather than bright against the dark background of space.
The Sun in H-alpha, on 2010 June 11, by Pete Lawrence
This blog post is the first of our regular “Saturday Circulars“, in which we will highlight a news article from one of the BAA sections’ newsletters. This article was written by Phil Morgan, a longstanding member of the BAA Lunar Section. It appears in Lunar Section Circular Vol. 47 No. 6 June 2010.
Plato’s Hook
In his famous book The Moon H.P. Wilkins shows an observation of Plato crater made with the Meudon 33-inch refractor, dated 3 April 1952. This detailed study shows a curious hook shape in the shadow falling from the inner east rampart of the crater.
Wilkins’ published observation of Plato and the ‘hook’ made at Meudon and taken (courtesy Bill Leatherbarrow) from Wilkins’ recently discovered notebooks.
Wilkins' original observational sketch of the 'hook'
Many believed that this was a mistake by Wilkins, but on 3 May 2009, Maurice Collins (Palmerston North, New Zealand) secured a series of images that seemed to confirm Wilkins’ findings.
Maurice Collins produced LTVT simulations of Plato as it appeared on 22 April (for 21:15 UT, above), which confirm that the hook effect is very short lived, hence the dearth of confirmatory observations by other observers.
On 22 April this year I made an observation of Plato that also shows this strange hook effect to the inner shadow profile. The observation commenced at 21:15 UT when the ‘hook’ looked very pronounced. By 21:30 UT the effect had diminished, but was still decidedly hooked in shape.
Phil Morgan's observational sketch of Plato's 'hook' from2010 April 22 at 21:15UT
I passed this observation on to Maurice Collins, who was, naturally very pleased to see confirmation of his own study. Utilising Jim Mosher’s excellent LTVT programme, Maurice produced a couple of simulations of the shadow profile for the timing of my observation.
The results are interesting and do appear to confirm the hook effect. The first one timed for the start of my observation, shows the hook effect clearly, and the second timed for the finish 15 minutes later, confirms my findings that the hook had started to diminish and that the effect is a very short lived one — hence the lack of confirmation by most other observers.
It is difficult to say just what causes this hook in the shadow profile on the floor of Plato, but it could be down to the shadow sometimes falling into a small circular depression on the crater floor. In his other book Our Moon, Wilkins shows the same observation, but with the hook less pronounced, but just why he did this no one knows!
I also asked Colin Ebdon if by any chance he had been observing Plato on 22 April. Unfortunately, not specifically, but he did happen to take two images of Plato shortly after my observation finished — the first at 22:00 UT and the second at 22:26 UT. These are interesting to me since they confirm the general shadow profile that I had recorded a bit earlier, a pity that he didn’t image the region 30 minutes earlier!
Colin Ebdon’s image of Plato on 2010 April 22 at 22:26 UT.
To find out more about the BAA Lunar Section see our previous blog post: About the BAA: Lunar Section
The bi-monthly Sky Notes from the BAA Journal are written by Callum Potter, and are available for all to download as a PDF. These cover the major events of interest, and suggestions for observing over a two month period.
2010 June / July Sky Notes
It is now a year since I started my first Sky Notes, and having come full circle I’ll have to take care not to repeat myself. As principally a deep-sky observer, I do tend to treat these summer months as a holiday due to the shortness of the truly dark nights needed, but even in some of the short periods of darkness there are a few sights available − and of course the planets, the Moon, and the Sun are not so badly interfered with, so useful observations can still be made.
As mentioned in the last Sky Notes there was an interesting approach to the Beehive cluster (Praesepe) by Mars in April. Nick James captured this image of the event on April 16 at 21:30 UT. EOS 10D digital SLR, Megrez 72 APO refractor, 4×300s.
Sun
The summer solstice occurs on June 21 at 11:28 a.m. This marks the time when the Sun is at its apparent highest declination in the year, and marks the start of summer. No doubt the druids will be gathering at Stonehenge for the event, and if you get the chance there may be some interesting and evocative pictures to be had around the stones. However, research indicates that for our prehistoric ancestors the winter solstice was much more important. It may seem strange to us in July in the northern hemisphere, that we are actually at our furthest from the Sun at this time, with the Earth being at aphelion on July 6, some 152.6 million km distant, about 5 million km further than at perihelion in January. Solar activity has been increasing, and small sunspot groups and prominences are being frequently observed. So whether you have a dedicated solar telescope, or just make occasional observations using a filter or the projection method, it is well worth taking any opportunity offered. There is a total eclipse of the Sun on July 11. However, this occurs over the south Pacific ocean, without much in the way of landfall. There are a few islands and atolls which will make ideal observing sites, the main being Easter Island, and no doubt there will be some cruise ‘missions’. It could certainly be an amazing holiday, to take in the eclipse and the culture and history of these Polynesian islands. And of course, reports of the eclipse will be most welcome.
Noctilucent clouds (NLC)
Much is still unknown about noctilucent clouds; these high altitude clouds are illuminated by grazing sunlight during the summer months, making them visible during the hours of darkness. They often have an electric blue appearance, which is quite distinctive. Last year was a good season with many observations reported. With the volcanic eruptions under the glacier Eyjafjallajokull in Iceland that caused so much disruption to the UK airspace, it will be interesting to note if this appears to have any effect on the incidence of NLCs. See this blog post for details of how to report your observations.
Moon
The Moon is New on June 12 and July 10, and Full on June 26 and July 26. The June New Moon will have a low altitude to the south, appearing just above the spout of the Teapot asterism of Sagittarius, and might make an interesting photo opportunity.
Planets
The apparition of Mercury in April was well seen by many members, but the planet is now at superior conjunction and unobservable.
Venus is still well placed in Gemini at the start of June and tracks through Cancer and on to Leo in July. As Venus is now closer, the disk is larger, but the change in phase maintains the same level of brightness. On June 15, Venus will be near to the slimmest of new crescent Moons, making a nice but difficult photo opportunity. Also on June 20 and 21 Venus will cross M44, Praesepe, or the Beehive Cluster – another interesting but tricky photo-opp.
Mars is moving through Leo, but its apparent diameter is reducing, and it is heading into evening twilight in late July. Mars and Venus are closing together in July, and Saturn is also in the area, so this could make an interesting photo, but again will be difficult due to the low altitude of the three. The new crescent Moon will add to the trio on the July 14 and 15.
Jupiter is improving, though still low in the east in the morning sky in June, but will be rising around midnight in early July making it more available. Uranus is close to Jupiter in both these months, which will make an easy finder for the distinctly blue/green planet, which displays a 3.5″ disk shining at around magnitude 5.8.
Saturn is heading towards the sunset, but will still be observable in June and July though low in the west. At the end of July there will be a nice conjunction of Mars and Saturn, with Venus nearby too, which could make a nice little photo composition.
Saturn on April 17 imaged by Martin Lewis in St Albans with a 222mm Dobsonian and DMK21 CCD.
Neptune is between Capricorn and Aquarius, and is somewhat trickier, being 2 magnitudes fainter than Uranus, at around 7.8, with a disk of 2.3″. However, Neptune does have a distinct blue colour. It is interesting to contrast the colours of Uranus and Neptune. Both have similar proportions of methane in their atmospheres, but Neptune is somewhat bluer, and it is unclear why.
Pluto is at opposition on June 26, but faint around 14th magnitude, and in amongst the star clouds between Scorpio and Scutum, making visual observation very difficult, though with a CCD you should be able to detect its motion over a couple of evenings.
Meteors
The bright nights do not make this period the best for meteor observing, though the Ophiuchids have a double maximum on June 10 and 20, but low rates with a ZHR of 5. There are favourable maxima of the Capricornids on July 8 and 15 but again with low rates, also with a ZHR of 5.
Comets
This has been a lean time for comet observers, but there have been a few fainter comets worth following recently. Recent observations of Comet McNaught (2009 R1) suggest that it may become naked eye towards the end of May and into June. It will be low in the east and north east, as it moves from Andromeda, through Perseus, and into Auriga. By the end of June, however, it will be unobservable from the UK.
Variable stars
In last years June/July Sky Notes I mentioned that the variable star R Corona Borealis was still dim, and due to brighten soon to its normal level of around magnitude 6. However, surprisingly, this year the star is still dim at around mag 14. So observations would be appreciated by the Variable Star Section, and if you notice a brightening, please let the Section Director know immediately. Finder charts for R CrB can be found on the VSS website, in the Charts area
Deep sky
Although this is not the best time of the year for observing ‘faint fuzzies’ it is not impossible to see some of the brighter sights. The galaxies M81 and M82 in Ursa Major are an interesting pair, M81 being a traditional spiral galaxy, and M82 an active irregular galaxy. M81 was discovered by Johann Bode in 1744, and is sometimes knows as ‘Bode’s Galaxy’. Messier later re-discovered it and added it to his catalogue. To find the pair I tend to use a nontraditional star-hop. Often it is recommended to go from Phad at the bottom left of the square of the Dipper across the diagonal to Dubhe, and continue in the same direction, for the same sort of distance, and you’ll land in the vicinity of M81 & M82. I find that with this route there is quite a jump from Dubhe into ‘open space’, so I prefer to follow from Megrez to Dubhe, and then onto 23 UMa, north to 24 UMa, and then just track a little west to reach the pair. Whilst around Ursa Major, one of the curiosities of the Messier catalogue is M40 – which is in fact just a double star. Messier was searching for a nebula identified by Hevelius, but he did not find anything nebulous in the area, but he found this double, and having measured the location, he put the object into his catalogue. It was catalogued later as Winnecke 4, which it is how it is listed in some star charting software. They might be difficult but the other three Messier galaxies of Ursa Major should also be sought – M101, the Pin Wheel Galaxy is a fine spiral, M108 an edge-on spiral, and M109 another nice barred spiral.
Galaxy M81 imaged by Peter Edwards on 2010 March 7 with a Celestron C11 at f/6.3 and SBIG ST2000XCM CCD camera. 18×300sec sub-exposures stacked to give a total of 90 minutes.
From BAA electronic bulletin No. 00499:
The Wrottesley Observatory at the Black Country Living Museum will be holding their 2010 Summer Solstice Event on Sunday 20th June from 10.00 to 4.00.
Black Country Living Museum, Tipton Road, Dudley, West Midlands DY1 4SQ
There will be tours of the Museum’s Victorian observatory, displays and talks and, weather permitting, solar observing with a number of instruments both vintage and modern.
Visitors should also be able to use BAA instrument No. 150, the 7-inch f/11 reflector by George Calver (see BAAJ 119,1,40,2009).
Entry to the event on the day is the normal Black Country Living Museum admission price – Adult £13.20, Child £7.00 and Senior £10.70.
To book or for museum details ring 0121 557 9643 or 0121 520 8054. See
also the museum website.
This blog post is taken from a news bulletin issued by Dr John Rogers, the Director of the BAA Jupiter Section, about the 2010 June 03 impact on Jupiter.
A new impact has been detected on Jupiter. This time the impact flash was recorded directly, by two independent observers, both amateur astronomers. It was first reported by Anthony Wesley (Australia), and confirmed by Chris Go in a video taken at exactly the same time: 2010 June 3, 20:31:29 UTC. It was a very bright flash lasting about 2 seconds, so there can be no doubt that it was an impact; no internal event in Jupiter would produce such a bright brief flash.
Images of the bright impact spot on Jupiter (Anthony Wesley and Chris Go)
It was in the faded South Equatorial Belt (SEB), about 50 deg. preceding the central meridian; Wesley’s preliminary measurements put it at Longitude L2 = 342.7, L3 = 159.4, Latitude 16.1 deg.S.
Nothing further was seen at the impact site in the half-hour before it disappeared round the limb. When it reappeared, the next morning around 03:30 UT , observers in England, France and Italy looked for an impact spot but recorded nothing definite. However, the images were at low resolution (due to the low altitude and bright dawn sky), so the images do not exclude a smaller scar. Observations of this site over the next few days will be very important.
| Amateur astronomers Anthony Wesley (whose video this is) of Australia and Christopher Go of the Philippines have independently observed an impact event on Jupiter. The strike occurred at 20:31 UT on June 3rd, 2010 and produced a bright flash of light in the giant planet’s cloudtops.
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Even if no ’scar’ is detected, this would not be surprising. The direct imaging of the SL9 impacts in 1994 by the Galileo spacecraft showed a bright flash a few seconds long like this one even for a small fragment which produced virtually no scar, probably because a small impactor can explode high in the atmosphere. So, impacts like this could be frequent, but never before recorded, and still consistent with the rarity of larger impacts that leave obvious traces.
By the way: Uranus is 0.5 degrees north of Jupiter at present: a good opportunity to compare the two giant planets.
This blog post is the first of our regular Thursday “From the BAA Journal” series. This series features a selection of articles, news, reviews and letters from the Journal of the British Astronomical Association, published six times a year.
Look out for Noctilucent Clouds this Summer
Noctilucent clouds (NLC) have been seen very frequently throughout the UK and Europe for the past number of years. Recently the frequency has been such that NLC have been reported from somewhere on almost every night in June and July. Previously believed to be a phenomenon most often seen in more northern latitudes, reports are now being received from as far south as Portugal and Spain. 2009 proved to be probably the most active year on record with NLC reported on 68 nights in 721 observations, and many displays were thought to be brighter than in previous years.
Noctilucent Clouds
The Sun may have some effect on the frequency and brightness of NLC and having been at a low level of activity for some while is now showing signs of recovery. It will be interesting to see if increasing solar activity will change the pattern of NLC frequency and brightness over the next few years.
The BAA Aurora Section recognises the huge amounts of data which BAA members provide every year and thanks members for their continuing effort. Many reports received contain data for an entire night, the observer finally giving up as the sky brightens with dawn. This degree of dedication, however, is not necessarily required and any members who see NLC during the evenings and mornings this summer, even for a few minutes, are invited to send details to Ken Kennedy, the BAA NLC co-ordinator, or post them on Tom McEwan’s website. The essential details required are your name, when the NLC was seen, giving a date for whatever time the observation is made, and the time (please state if UT, BST or other local time). The location is also useful as it is interesting to know the most southerly sighting on each night. Details such as forms of NLC seen, brightness, elevation and azimuth may be given if the observer feels confident. Further details for observers may be found on Tom’s website (‘Observing noctilucent clouds’).
This blog post is based on an article in the Journal of the British Astronomical Association. For 120 years the Journal has published the observations and work of BAA members. It also contains many other articles and items of interest to all amateur astronomers.It is published six times a year, and sent free to all full members of the BAA. Find out how to join the BAA here. Members are also able to download current and previous issues of the Journal from the Members | Downloads section of the website. For subscription details for non-members, please contact the BAA office.
A new comet is rapidly brightening in the morning sky as it sweeps through the solar system and approaches the Sun.
Comet McNaught, imaged by Michael Jager
Comet McNaught (C/2009 R1) can be seen as a barely-visible (5th or 6th magnitude) object in the constallation of Perseus low in the northeast just before dawn, and over the next few weeks it is expected to brighten considerably (up to around 2nd mag), although as it is a new comet this isn’t entirely certain.
If you want to spot the comet then pre-dawn observing is required. These handy location charts are available at Heavens Above:
Comet McNaught location chart (coarse)
Comet McNaught location chart(fine)
The BAA website has a new Comet McNaught gallery, including this image by Martin Mobberley taken four days ago, on 05 June :
Comet McNaught, imaged by Martin Mobberley
For more information on comets visit the BAA Comet Section
@britastro