Yesterday evening, following much agitation of the Earth’s magnetic field, an aurora (the northern lights) was viewed by many from the north of Scotland. Poor weather in other areas may have prevented views further south.
BAA member Denis Buczynski captured a few images of the display from Portmahomack, which will give a flavour for what was seen. These were taken between 20:58 and 23:48 with a Canon 400D and a 28mm lens at f2.8 at ISO 800. Exposures were all about 30 secs.
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.
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.
The Sun has been very active this past week and John Mason, who is currently in Norway, reports that spectacular aurorae have been seen over the last few days. The images here were taken on the night of January 24/45. John writes:
I took a total of 508 images that night using a Canon EOS 450D with 10 mm f/2.8 Sigma fish-eye. All images were at 1600 ISO with exposure times ranging from 1s to 15s during the night, depending on the brightness of the auroral structures being imaged and the steadiness of the ship at the time. During the most active part of the display exposures ranged from 1s to 6s. During the auroral display, I was observing from the aft of deck 9 on the Hurtigruten ship M/S Midnatsol, which was sailing roughly northwards from Tromsø to Oksfjord, via Skjervøy at the time.
There are more of John’s spectacular images below and John even made the Washington Post.
UK observers were unable to witness for themselves the close-pass of near-Earth asteroid 2005 YU55 on the night of 2011 November 8/9 owing to the country being entirely covered by impenetrable cloud as can be seen in the weather satellite images taken at the time.
‘YU55′ is especially noteworthy in that it is the largest known NEO to have passed so close to the Earth (0.85 lunar-distances away) that has been predicted in advance of the event. Detailed radar images including animations showing the object rotating will be released by NASA during the next few days, news of which can be found at:
Given the poor weather in the UK, BAA member Martin Mobberley used a remotely-operated 0.5-m telescope at the GRAS facilities in New Mexico to secure a 1-minute exposure of the 11th magnitude object taken some 7 hours after closest approach. The very fast moving object is clearly visible as a bright streak in the centre of Martin’s image taken whilst it was at a distance of about 450,000 km from the Earth, just beyond the orbit of the Moon.
Director, Asteroids and Remote Planets Section
BAA members around the country managed to combine to produce a fine set of images over four nights to capture the passing of Comet 2009 P1 Garradd over the Coathanger.
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.
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.
BAA member David Arditti took these two excellent images of nebulae in Cygnus during October 2010: NGC 7000 (the North America Nebula), and the much smaller IC 5146 (the Cocoon Nebula). Both are emission nebulae, clouds of ionised gas emitting light in various colours.
As David explains: “T[hese images] were both taken from outer London but in completely different conditions and with completely different systems.
“IC 5146 was taken with an uncooled, unmodified DSLR on a dark night, using a light-pollution filter, and a Newtonian of 48 inches (1219mm) focal length. The telescope was on a Fullerscopes MkIV mount with AWR control system, autoguided off-axis with a DMK camera.
“NGC 7000 was taken with a cooled monochrome CCD on two brightly moonlit nights using a combination of narrow and broad-band filers and a refractor with focal reducer of focal length 12.3 inches (311mm). The telescope was on an Astro-Physics 1200 GTO mount and no guiding was used, or necessary. The colour mapping is slightly unusual: I have used the H apha as red, the red as green, and the blue as blue. This seems pretty effective at limiting the effect of light pollution, and gives a fairly pleasing balance. (It is not dissimilar to the “Hubble palette” which also takes the green channel from the red end of the spectrum). I also applied a luminance layer from the H alpha data. The Astronomik 12nm filter does suffer from the drawback of giving haloes round bright stars (it is one of the cheapest H alpha filters) but they are not too intrusive when the data is combined with that from other filters.
“Comparison of these two images does actually show how much less noisy results from a cooled CCD are compared to those from an unmodified DSLR.”
You can download the images here:
2003 UV11, a relatively large near-Earth asteroid measuring roughly 400-500 meters across, is currently making a close approach over the next few days.
In so doing it will become one of the brightest such objects for several years attaining a V magnitude of about 11.9 on October 29 and passing closest to the Earth at a range of 5.0 lunar-distances on 2010 October 30 at 04:14 UT.
Although we know the orbit of this object with high accuracy and details of this close approach have been listed in the BAA Handbook for 2010 (p.55), we do not know a great deal about its physical nature including its rotation period. The close pass therefore represents an excellent opportunity for observers to obtain images suitable for photometry. From the UK, the most favourable observing times (UT) will be the nights of Oct 26/27 (20h-03h), Oct 27/28 (20h-03h), and in particular the two nights of Thursday, Oct 28/29 (19h-02h) and Friday, Oct 29/30 (18h-0h) when it will reach magnitude 12 and be moving at 50-60 arcsec/min and 130-160 arcsec/min respectively. Visual observation through a telescope on the last night should also prove very rewarding as it will then be possible to see it moving in real-time – a rare opportunity for such a bright target!
Please pass any good quality images to the BAA Asteroids and Remote Planets Section Director Richard Miles. For photometry, exposure times are best kept short although short trails can still be used. Near closest approach, exposure times of up to 20 sec should be fine. (N.B. Longer times are helpful in that the reference stars are recorded with good signal-to-noise.) Fortunately for observers, the object is favourably placed well south of the Milky Way sweeping through the constellations of Aries, Pisces and Pegasus where the starfields are not too crowded.