It could appear that All Hallows’ Eve is an efficient time to identify near-Earth objects (NEOs). In 2015 we had the shut passage of an appropriately skull-shaped useless comet, designated 2015 TB145, that missed our planet by simply 1.3 lunar distances, or about 302,000 miles (486,000 kilometres). This 12 months, it’s the flip of asteroid 164121 (2003 YT1) to go Earth by a considerably safer margin — 3.2 million miles (5.2 million kilometres) at 9:24am GMT on 31 October 2016.
NEO 164121 (2003 YT1) is a 1.7-kilometre-(1.1-mile)-wide Apollo asteroid found by the Catalina Sky Survey on 18 December 2003. It completes an orbit each 427 days in a considerably eccentric ellipse that carries it to inside 73 million miles (118 million kilometres) of the Solar. The asteroid additionally has an orbit with a comparatively excessive inclination of 44 levels, which has attention-grabbing penalties for the thing’s visibility over the following few days.
Because the final day of October 2016 dawns, 2003 YT1 is already a circumpolar object for observers within the British Isles the place it should stay above the horizon 24/7 till the third week of November. The asteroid’s movement is northerly, nearly solely in declination at the moment.
Photographing 2003 YT1 close to Polaris: no costly monitoring mounts required!
As seen from the guts of the British Isles, 2003 YT1 passes simply 4.6 arcminutes — lower than one-tenth of a level — from Polaris at 02:30 UT (2:30am GMT) on 2 November. Since this near-Earth asteroid passes so near the pole star, an attention-grabbing astrophotographic alternative presents itself: nearly anybody with a tripod-mounted DSLR digital camera who can get to a darkish sky web site can have a go at capturing 2003 YT1.
Any object passing this near the north celestial pole shall be nearly stationary within the sky in the course of an publicity that shall be lengthy sufficient to report it. An 85mm lens, for instance, used with a typical APS-C sensor DSLR will ship a discipline of view nearly 15 x 10 levels in extent. (Our on-line DSLR Calc internet app will allow you to work out the sphere of view of different lens/digital camera mixtures.) Recall that the asteroid passes lower than one-tenth of a level from Polaris at closest method, so using an extended focal size lens implies that the NEO’s faint path is much less more likely to be misplaced within the glare of the pole star.
Merely focus your chosen DSLR lens on infinity at full aperture (you need to use a distant landmark throughout the daytime for this, being cautious to not disturb the main focus of the lens till dusk), set the ISO ranking to 800 or 1600, level at Polaris and shoot some 30 second, 1 or 2-minute exposures with a cable launch. If in case you have the suitable software program in your pc, stacking a number of of those rigorously registered photos (every of the identical publicity time) will enhance signal-to-noise ratio and 2003 YT1 shall be recognized because the dot that strikes between photos.
Viewing 2003 YT1 close to Polaris
In case you are lucky to have clear skies round 02:00 UT (2am GMT) on 2 November, notice that it is a uncommon alternative for customers of undriven telescopes equivalent to Dobsonians to watch an object at size with out the necessity for monitoring. In reality, homeowners of telescopes on alt-azimuth mounts are at a definite benefit right here since equatorial mounts are harder to make use of so near the celestial pole.
If in case you have a telescope with an aperture of 6-inches (150-millimetres) or bigger, get Polaris inside the discipline of view of your medium- to high-power eyepiece near the appointed time and search for the twelfth-magnitude speck of sunshine that’s 2003 YT1 shifting in opposition to the background stars of Ursa Minor at a fee of 12 levels per day, or half a lunar diameter per hour.
Ephemeris of 2003 YT1 for the UK
Contained in the journal
For a complete information to observing all that’s occurring within the present month’s sky, tailor-made to Western Europe, North America and Australasia, get hold of a replica of the November 2016 edition of Astronomy Now.
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