Astroblog: Watching NEO 2015 TB145 from Australia (31 October, 2015)

Friday, October 16, 2015

Watching NEO 2015 TB145 from Australia (31 October, 2015)


NEO 2015 TB145 at midnight on 31 October 2015, it is just above the shield of Orion. Click to embiggen.	NEO 2015 TB145 at astronomical twilight on 31 October 2015, it has moved towards the bottom of the shield of Orion. Click to embiggen.

Near Earth Asteroid 2015 TB145 with an estimated diameter of around 460 m will come relatively close to Earth on 16:18 UT, 31 October (3:18 am 1 Nov AEDST) at distance of 0.003 AU (around 1.3 Earth-Moon distances, ie it is further away from us than the Moon, so there is no chance it will hit us). It is brightest at 12:30 UT on the 31st though (11:30 pm 31 Oct AEDST).

At this time the asteroid will be a reasonably bright magnitude 10.1, easily visible in small telescopes and strong astronomical binoculars. Unfortunately from Australia we will be unable to see it as it is in the northern hemisphere.

Black and white chart suitable for printing showing the track of the asteroid from midnight to sunrise and beyond on 31 October. The circle shows the field of view of 10x50 binoculars (although you will not be able to see it in binoculars, this simulates the FOV of a finder scope).

The asteroid is near Orion's Shield. Tick marks are an hour apart. Click to embiggen and print. Use the charts up above to orient yourself first.

NEO 2015 TB145 moves from Taurus to Orion, then back into Taurus (crossing the horns of the Bull), into Auriga (where it is brightest) then on to Lynx and beyond.

Australia's best view is on the morning of the 31st, when the asteroid brightens from magnitude 13 to magnitude 12.5. It will be visible in amateur telescopes (as a faint dot), however, the still bright waning Moon 17 degrees away will make it a bit tricky to spot. Its movement should be obvious over several minutes in a medium power telescope eyepiece.

Black and white chart suitable for printing showing the track of the asteroid from midnight to sunrise and beyond on 31 October. This chart is suitable for telescopes. The chart is inverted with respect to the finder chart above.

The circle is the field of view of a 20 mm eyepiece with a Newtonian reflector scope. Tick marks are 30 minutes apart. Click to embiggen and print. Use the binocular charts up above to orient yourself first

The asteroid is currently magnitude 19.5, and will not really be accessible to modest amateur equipment until the 30th. You can get an accurate ephemeris for your location from the Minor Planet Ephemeris Centre or JPL horizons. It is best to wait a few more days to generate an ephemeris as better position data is gathered.

Labels: alert, asteroids, NEO, telescope