Project Neil Bone

Initiated and coordinated by Richard Miles

Project Neil Bone

Aim of the project

Observe the selected asteroids at opposition and ,also, while approaching

and receding so as to record the opposition effect.

Compare the effect between different asteroid classes.

Project Neil Bone

P h ase A n g le

S u n

E a rth

A ste ro id

Opposition effect

Project NeilBone:List B - updated 2009 Dec 14

LOW PHASE ANGLE TARGETSOpposition Rotational Observed Notes

Asteroid Asteroid Asteroid Opposition Minimum Min. Observed V Lightcurve ObservedLightcurveNumber Name Type Date Phase Angle Phase Angle Mag Dec. Period Amplitude Period Amplitude

m d deg deg h mag mag2009

150 Nuwa Cb 10 23.8 0.08 0.10 11.5 +11 8.14 0.09 8.134 0.151130 Skuld S 10 24.9 0.18 0.19 13.5 +12 4.81 0.5 4.806 0.26384 Burdigala S 11 08.7 0.13 0.17 12.1 +16 17 0.03 400 0.32 on-going770 Bali S 11 10.2 0.27 0.82 12.2 +18 5.951 0.40-0.55 missed coverage close to opposition138 Tolosa S 11 15.1 0.08 0.08 11.5 +18 10.101 0.4 on-going

1423 Jose S 11 20.1 0.02 0.02 13.8 +20 12.307 0.68-0.82 on-going121 Hermione Ch 12 08.1 0.17 0.17 11.6 +23 5.551 0.04-0.45 on-going

1645 Waterfield XDC 12 12.5 0.06 0.06 14.5 +23 4.861 0.2 on-going171 Ophelia C 12 16.6 0.35 not a target 12.2 +22 6.665 0.14-0.45

2010581 Tauntonia Xk 01 04.2 0.18 13.8 +23 16.54 0.06 on-going702 Alauda B 01 08.8 0.28 not a target 11.7 +23 8.36 0.1

7102 Neilbone ? 01 18.3 0.03 17.5 +21 ? ? on-going484 Pittsburghia S 01 27.3 0.02 13.5 +18 10.63 0.37 on-going625 Xenia Sa 01 28.8 0.09 not a target 14.3 +18 21.101 0.5 too faint and near Moon when at opposition64 Angelina Xe 01 29.6 0.003 10.2 +18 8.752 0.42 on going - near full Moon at opposition59 Elpis B 03 13.3 0.18 11.9 +3 13.69 0.2

996 Hilaritas B 03 15.8 0.05 14.3 +2 7.2 0.691451 Grano S 03 17.2 0.08 14.2 +2 5.109 0.06658 Asteria S 03 23.9 0.16 14.4 -2 21.034 0.32495 Eulalia S 03 25.0 0.06 14.2 -2 29.2 0.373 Klytia S 03 29.9 0.04 12.4 -4 8.297 0.35

1225 Ariane S 03 31.2 0.10 14.2 -4 5.507 0.36

Project Neil Bone

Observation record Up to 2009/12/15

Object Opp Mag Date Av Mag Error Date Av Mag Error Date Av Mag Error Date Av Mag Error Date Av Mag150 Nuwa 11.5 Oct 11/12 11.907 0.018 Oct 24/25 11.787 0.009 Oct 25/26 11.717 0.009 Nov 08/09 12.183 0.021 Nov 09/10 12.2151130 Skuld 13.5 Oct 24/25 13.401 0.024 Oct 25/26 13.596 0.02 Nov06/07 14.085 0.043 Nov16/17 14.636 0.08384 Burdigala 12.1 Nov 08/09 12.05 0.013 Nov 09/10 12.067 0.018 Dec 06/07 12.728 0.014 Dec10/11 12.885 0.0181423 Jose 13.8 Nov 14/15 14.321 0.046138 Tolosa 11.5 Nov 14/16 11.619 0.011 Nov 16/17 11.695 0.013 Nov 17/18 11.773 0.008 Dec 06/07 12.368 0.009 Dec10/11 12.503121 Hermione 11.6 Dec 06/07 11.691 0.005 Dec 12/13 11.998 0.005 Dec 13/14 11.865 0.011645 Waterfield 14.5 Dec 06/07 14.914 0.062 Dec 12/14 15 0.057 Dec 13/15 14.818 0.054581 Tauntonia 13.8

Differential photometry is employed to measure the asteroids brightness.

240 second guided exposures to acquire a good signal to noise ratio.

MX916 camera @ f10 on a 235mm SCT

‘V’ filter

Lodestar guide camera on a 90mm Maksutov

So what do we learn from all this:

• The opposition effect gives information regarding

the surface regolith structure which may differ for different asteroid taxonomic classes.

• The phase curve contains information about its shape and rotation period.

• This in turn gives us an idea of whether it is a solid object or a rubble pile.

• It may show whether a companion is present i.e. whether it is a binary asteroid.