UPDATE: Seeing the Close Flyby of NEO 2004 BL86 10 pm 26 January, 2015

In my previous article on 2004 BL86 I explained in detail how to see this NEO at its brightest … at around 4:30 am in the morning when it is close to the bright open cluster M48. For those of you who want to see it on the night of the 26th, before heading to bed, I’ve created these instructions.

You will need a telescope, not a fancy one, but a telescope none the less. Finding the asteroid will be harder as it is dimmer, and there is no obvious bright feature to use as a guide. But while harder it is well worth the effort.

To find the asteroid, again we will use bright stars as a landmark. If you draw a line between Jupiter and Canopus (the brightest  and third brightest objects in the sky at this time), then draw a line perpendicular from Sirius (the second brightest object in that part of the sky) to the Jupiter – Canopus line, the intersection is where the asteroid will be.

In binoculars or a telescopes finder scope you will see a triangle of stars. The faint star at the apex of the triangle is 11 Pupis. The asteroid zooms past this star as seen from the eastern and central states. From WA, by the time the sky is darkenough, the asteroid is well below 11 Puppis, but you can use the charts to sweep down and find it.

Printable black and white binocular chart  showing the location of 2004 BL86 at 22:00 to midnight  ACDST on the evening of 26 January 2015 from Adelaide. The circle the approximate field of view of a 25 mm eyepiece with a 114 mm Newtonian telescope. The orientation is upside down from the binocular map as telescopes invert the image. Click to embiggen and print.

 With your telescope a wide field eye piece, first centre 11 Pupis in the eyepiece, then move it so 11 Puppis is at the western edge of the eyepiece. The asteroid should be visible as a faint dot on the western side, moving slowly but inexorably across the stars.

The printable charts above will be needed help you find the asteroid.Remember, when looking for the asteroid allow at least 5 minutes or more (10 is better) for your eyes to adjust and become dark adapted. Here’s some hints on dark adaption of your eyes. If using the charts above, cover your torch with red cellophane so as to not destroy your night vision.