We are now just a few days away from the dramatic passage of this near-Earth asteroid, which takes place on 2013 February 15 approaching to within 27,700 km of the Earth’s surface at about 19:24 UT on that day whilst travelling at 7.8 km/sec. During the last week many more observatories have imaged the object, in particular; Mount John Observatory, New Zealand (MPC Code 474); the 2.0-m Faulkes Telescope South (which is now back in business after last month’s devastating bushfires which badly affected Siding Spring and the surrounding community) (MPC Code E10); as well as the new LCOGT 1.0-m ‘B’ telescope at Cerro Tololo, Chile (MPC Code W86).
Reaching 7th magnitude, it will be the brightest-ever NEO to be observed approaching the vicinity of our planet (<0.1 AU) and will be visible with modest telescopic aid, e.g. binoculars. 2012 DA14 will pass about 10x closer to the Earth than our companion Moon. To put this in perspective, scientists at NASA’s Near-Earth Object Program Office in Pasadena, California estimate that an asteroid the size of 2012 DA14 flies this close every 40 years on average and that one will impact Earth, on average, about once in every 1,200 years!
Depending on your location, you are advised to obtain your local topocentric RA and Dec coordinates from websites such as can be found at:
Minor Planet Center ephemeris service
You will need to enter either your latitude and longitude, or the MPC Code of a nearby observatory.
I have prepared a chart for the interval 19:50-21:00 UT in anticipation of the object’s visibility soon after it rises near the eastern horizon as seen from the southern UK. A second chart covers the later period, 21:00-01:00 UT on the evening of Feb 15/16. Full observing details and a 5-minute ephemerides for UK observers are also available here. The charts are probably usable by all UK observers since the object will be conspicuous owing to the fact that it will be seen to be moving in real time. Look with binoculars or a small telescope within a degree or so of the predicted position at any given time and it should ‘jump out’ as a moving star.
The weather forecast for most of the UK is not especially favourable owing to excessive cloud but watch out for gaps which may appear especially in the Norfolk area. Observers located in north-east Scotland may be best-placed weather-wise. Currently southern Spain is predicted to have clearest skies in Europe for this event. Further weather updates will be provided.
NASA have set up a very informative webpage with useful FAQs, orbit diagrams and some videos of interviews, etc.
Richard Miles (Director, Asteroids and Remote Planets Section)
An unusually large Near-Earth Object, 2012 LZ1 has just been discovered by Rob McNaught and colleagues on 2012 June 10/11 using the 0.5-m Uppsala Schmidt telescope at Siding Spring, Australia as reported in MPEC 2012-L30 issued on June 12 09:30 UT.
The newly-discovered NEO is approximately 300-700 metres in size (H=19.7) and makes its closest approach of 0.036 AU (about 14 lunar-distances) on June 15.0 UT. The object will be visible from the UK near closest approach rather low down in a south-eastly direction and may be best seen before dawn (around 01:00-02:00 UT) on Friday, June 15 as an asteroidal object, magnitude 13.9 or so, moving at an apparent speed of about 38 “/min at an altitude of roughly 25 degrees above the horizon.
BAA Member Martin Mobberley captured these images using a remote telescope in New Mexico.
NEO 2012 LZ1 imaged by Martin Mobberley on 2012 June 14
NEO 2012 LZ1 imaged by Martin Mobberley on 2012 June 15
Unusually too, although moving in an orbit inclined at 26 degrees, its motion is quite commensurate with that of the Earth at the moment and so the object will remain visible from the UK on many successive nights as it moves further northwards.
During the next ten days, the declination, brightness and apparent speed will be as follows:
June 14/15 Decl. -15 V=13.9 38″/min
June 15/16 Decl. +01 V=14.2 36 “/min
June 16/17 Decl. +13 V=14.6 30 “/min
June 17/18 Decl. +23 V=15.1 23 “/min
June 18/19 Decl. +31 V=15.6 18 “/min
June 19/20 Decl. +37 V=16.0 13 “/min
June 20/21 Decl. +42 V=16.4 10 “/min
June 21/22 Decl. +46 V=16.7 8 “/min
June 22/23 Decl. +49 V=17.0 7 “/min
Note that the summer solstice this year occurs on June 20 at 23h UT at which time this object will be visible from the UK in a westerly direction at an altitude of some 54 degrees.
Given its size and proximity to the Earth, 2012 LZ1 is the latest potentially hazardous asteroid (PHA) discovered.
Congratulations to Rob McNaught on this particular find which was conducted as part of the Siding Spring Survey; an NEO search program, the southern hemisphere counterpart of the Catalina Sky survey.
See: http://www.mso.anu.edu.au/~rmn/
Sky coordinates for finding this new visitor to the Earth’s neighbourhood can be obtained from the Minor Planet Center’s ephemeris service at:
http://minorplanetcenter.net/iau/MPEph/MPEph.html
Remember to enter a suitable Observatory Code in the online form to achieve a satisfactory topocentric prediction. For the UK, you might wish to use the Code for Greenwich namely ‘000′.
Observers are encouraged to report astrometry to the Minor Planet Center.
Please report photometry to the nearest 0.01 mag to Richard Miles, Director, Asteroids and Remote Planets Section, British Astronomical Association
arps [at] britastro.org
BAA member Nick James was able to respond to an urgent request for observations of the newly discovered near earth asteroid 2012 BX34.
He was able to image the asteroid last night (January 26th) from Chelmsford, one day before its closest approach at around 15:30UT today.
Image of asteroid 2012 BX34 by Nick James
Nick writes:
Following an alert from ARPS director Richard Miles I observed this very small Near Earth Asteroid last night from Chelmsford. The asteroid had only been discovered the night before and is due to come within 0.2 lunar distance of the centre of the Earth at around 15:30 UTC today. It is probably only 4-5m across.
Observations using the Goldstone Solar System Radar were scheduled for this morning and so an urgent request went out for astrometry of this object to help refine the orbit. The attached image shows one of my observations. The asteroid was moving so fast (around 30 arcsec/min) that I had to take short exposures but it was relatively faint (around mag 17) so they needed to be stacked. This stack consists of 36 frames offset at the expected rate of the object. It is visible as a dot and the background stars are the trails. The gap was caused by a short break to take a couple of dark frames.
You can also read more about this asteroid on the BBC News website.
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.
UK Cloud on November 8-9
‘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:
http://www.jpl.nasa.gov/news/index.cfm
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.
2005 YU55 on 2011 November 9th at 06:38 UT - Martin Mobberley
Richard Miles
Director, Asteroids and Remote Planets Section
Next week, there will be a chance to observe the close approach of the potentially hazardous asteroid (PHA) 2005 YU55. This 400m size object will pass by the Earth at about 325,000km (about 0.85 of the distance from the Earth to the Moon) on November 8th. However it will be low in the south west at sunset, so observations from the UK will be tricky. Over the following two nights, though, it will be more accessible.
Chart for 2005 YU55 (in Pisces) on 2011 November 9/10 - Martin Mobberley
BAA Asteroids Section Director, Dr. Richard Miles explains more…
Seen from the UK on the evening of Tuesday, November 8/9, a 400-metre size asteroid 2005 YU55 will pass within 0.85 lunar-distances of us travelling at a speed of 13.7 km/s relative to the Earth. This encounter will be the closest known for an asteroid of this size between the years, 1976 and 2028. So in this respect, it is a once in a 52-year opportunity to witness this particular skirmish.
It should first become visible from the UK and Europe on Tuesday evening, low in the west mainly in Aquila, passing 22 degrees south-west of Comet Garradd (C/2009 P1). It should prove fascinating to follow as it approaches. Seen from southern England (Dorset), it may be first detectable using a CCD camera and large telescope at about 18:00UT some 23 degrees altitude in the south-west direction at about magnitude 15 moving at 5 “/sec. It will brighten by about a factor of 10 over the next 4 hours so that by 22:00UT it will be 12th magnitude and moving at around 8 “/sec, i.e. crossing the sky at a rate of 1 Moon-diameter every 3.6 minutes. Even exposures of a few seconds will show the asteroid as a trail and only telescope mounts set up to track moving objects will be able to register it as a point source. It will attain 11th magnitude at closest approach (Nov 8 at 23:28UT) at an altitude of just 6 degrees (as seen from Dorset) and thereafter will set below the western horizon. With a very high apparent speed (reaching almost 9 “/sec), the object will be visible through large telescopes (25cm or greater) looking like a moving point of light crossing the field of view in a minute or two. Quite an observing challenge!
2005 YU55 will be much better placed for observers and easier to see on the evening of November 9/10 when at about 18:00UT it will be 12th magnitude and moving at <1 “/sec in the east close (12 degrees away) to the nearly full Moon. Martin Mobberley has kindly generated a finder chart showing the general position of the asteroid for the nights of Nov 9/10, 10/11 and 11/12. The chart can be found at:
http://martinmobberley.co.uk/images/2005YU55chart_mpm.jpgIf you are planning to observe then you will need to generate an ephemeris for a geographical location within a few hundred kilometres of your observing site. You may find the Minor Planet Center website convenient to use for this purpose, located at:
http://minorplanetcenter.net/iau/MPEph/MPEph.html
Be sure to enter an observatory code in the relevant box: “J95″ would be a good one to use by anyone in southern England. You will have to pick a short ‘ephemeris interval’ say 5 minutes so that you can point your telescope at a convenient spot which the asteroid will reach some minutes after the telescope has been trained on a suitable R..A. and Dec. Enter “2005 YU55″ in the large box and an ephemeris start date using the following format, “2011 11 09 1800″.The object was last observed in 2010 April when the Arecibo radio telescope was used to generate a radar image of the near-spherical object, and which was shown to be very dark and a slow rotator turning just once every 18 hours or so. See for example:
http://www.jpl.nasa.gov/asteroidwatch/newsfeatures.cfm?release=2010-144Although a potentially hazardous object, we do know that this is the closest approach the object will make to the Earth during the next 100 years.
All observations welcome. Good luck with the weather,
Richard Miles
Director, Asteroids and Remote Planets Section
BAA
arps@britastro.org
Asteroid 2011 MD on June 26 - Image by Nick James
Nick James from Chelmsford captured this fast moving near earth object on 2011 June 26. Images at 22:44 and 22:49 UT.
Closest approach will be at around 17:00 UT on the 27th June when the object will be around 8000 miles from the Earth.
More information about this interesting object can be found on the Sky and Telescope website.
If anyone else is successful in imaging this object, please email results to picture@britastro.org
This object was discovered on the night of April 8/9 by the Observatorio Astronomico de Mallorca (OAM) using a 0.45-m f/2.8 reflector at their La Sagra facilities (J75) in Andalusia, Spain (see http://www.minorplanets.org/OLS/ ). The observers involved were S. Sanchez, J. Nomen, R. Stoss, M. Hurtado, J. A. Jaume and W. K. Y. Yeung.
2011 GP59 is due to make its closest approach to the Earth on April 15 at 19h UT at 1.39 lunar-distances but will be brightest at an average magnitude of 13.2 around 00h UT on the night of April 14/15 when it will be very favourably placed in the sky for observers worldwide. This is the best NEO close approach these past few years and is bright enough to be observed visually in large (>0.2-m aperture) telescopes when on the night of Thursday 14th it will appear as a faint slow-moving star.
Observers should be aware however that the object, which is approximately 60 metres in diameter, appears to be rotating very quickly, once every 7.35 minutes in fact. It is also quite oblong in shape such that its rotation makes it look distinctly bright then faint every 4 minutes or so. David Briggs observing with the Hampshire Astronomy Group’s 0.4-m instrument on the evening of April 11 commented, “This is probably the fastest rotator I’ve seen so far in that it completely disappears from view every 3 to 4 images”.
Brian Skiff of Lowell Observatory has completed a lightcurve analysis which can be found at:
ftp://ftp.lowell.edu/pub/bas/astlc/2011_GP59.png
Close inspection of Brian’s results show that the object is almost certainly rotating around more than one axis, i.e. it is tumbling.
Weather for UK observers is likely to deteriorate over the coming days and so it might be best to observe tonight (Tuesday) around midnight or later when clear skies are forecast for much of England. Unfortunately it will only be 16th magnitude at that time and so will be too faint to be picked up visually. Positions can be found using the Minor Planet Center’s ephemeris service at:
http://minorplanetcenter.net/iau/MPEph/MPEph.html
Clear skies,
Richard Miles
Director, Asteroids and Remote Planets Section
British Astronomical Association
Postscript:
Nick James captured this video (YouTube) on night of 11/12 April.
The first well-observed case has been reported of a large main-belt asteroid apparently exhibiting ‘comet-like’ behaviour.
Steve Larson of the Lunar and Planetary Laboratory, University of Arizona, has reported that images of the minor planet (596) taken on December 11.44-11.47 UT with the 0.68-m f/1.8 Schmidt telescope at Catalina show theobject to be in apparent outburst with a comet-like appearance, exhibiting a total V magnitude of about 13.4 and an envelope that extends 2′ north and 5′ west of the central condensation (CBET No.2583 issued December 12). Note that the predicted magnitude of this asteroid at the time of Steve’s observation is about 60% fainter than the observed value.
BAA member Peter Birtwhistle obtained images from Great Shefford Observatory between December 12.178-12.204 showing the presence of a large arc to the north and smaller arc to the south in a field 3′x3′ in size – See: http://www.birtwhistle.org/Gallery(596)Scheila.htm
(596) Scheila is a large asteroid (diameter ~113 km) situated in the outer regions of the Main Belt, having a dark surface (albedo = 0.038). A rotation period of 15.8 hours has been reported and from the amplitude of its lightcurve(0.09 mag) it must be relatively spherical in shape. In other words it is a very ordinary, rather typical asteroid with no special features. Likewise its orbit is definitely asteroidal in nature and not cometary.
It has been speculated that we have just witnessed the aftermath of a high-speed collision between (596) and a small, non-descript object, perhaps no more than a metre or two in size. The two conjoined arcs visible in Peter’s stacked image are reminiscent of the arc-shaped material of ‘Comet P/2010 A2′ imaged by the Hubble Space Telescope in January of this year – See: http://hubblesite.org/newscenter/archive/releases/2010/07/image/a/
For this latter case, it has now been shown that this phenomenon was not cometary but was indeed the result of a collision between two small bodies in the asteroid belt.
Further observations of the evolution of the ‘debris’, dust, etc. around (596) Scheila should make it possible to discriminate between the collisonal hypothesis and a cometary origin. My money is on the former. Indeed, high-resolution spectroscopy of the emitted cloud of material could provide a unique opportunity to probe the composition of an asteroid by analysing the nature of the expelled material. Let’s hope that an 8-metre or 10-metre class telescope will be put to work doing just this in the very near future.
Checks should also be made on images of (596) taken in the past to see whether an associated coma can be found at some other epoch. If such a coma were to have occurred in the past then this would demonstrate recurrent activity characteristic of a true comet.
Close pass of bright near-Earth asteroid 2003 UV11
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!
Exact positions for your location can be obtained by going to either the Minor Planet & Comet Ephemeris Service or the JPL HORIZONS interface
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.
The long-term objective of the BAA Asteroid and Remote Planets Section is to be able to offer something to active, virtual and armchair observers e.g.; visual telescopic observing, imaging (photographic, CCD, webcam), virtual observing using on-line resources, orbital motion, the impact hazard, history of discovery and observation, general understanding of the planets and minor planets and space missions to those bodies.
Publications
An electronic section newsletter is issued monthly. The NEO website was relaunched as the section website, is updated quarterly and includes information on; asteroids, observing and imaging, meetings, space missions to minor planets, books and observational data supplied by members. The Minor Planet section of the BAA handbook has been expanded to include data on; brighter asteroids, astrometry, occultations, photometry and NEO close approaches. BAA Journal input has included reports of presentations at Observer’s Workshops, a paper by Fiona Vincent and a number of Note sand News items. The section entry in the BAA Observing Guide was also updated and section information prepared for John Mason for inclusion in the BAA new members pack. Material was submitted to Nick James in February 2007 for inclusion in a set of posters to be displayed at BAA Exhibition meetings. A number of BAA Electronic Bulletins issued relating to the close approach of several Near Earth Asteroids. Occultation predictions are circulated monthly by Assistant Director Andrew Elliott. The Section subscribes to and receives by email: Minor Planet Electronic Circulars from the Minor Planet Center and Electronic Telegrams from the IAU Central Bureau for Electronic Telegrams.
@britastro 
