Which Star Does the Moon Occult on December 23-24, 2015?

[guv]

On the night of December 23rd 24th 2015, an occultation of a bright star by the moon
will be visible from Britain to Japan. Given that the moon is in full phase on December
25th, which star does the moon occult?
a. Aldebaran (RA 4h 37m, Dec 16o 31’)
b. Pollux (RA 7h 45m, Dec 28o 2’)
c. Regulus (RA 10h 8m, Dec 11o 58’)
d. Spica (RA 13h 25m, Dec 11o 14’)
e. Antares (RA 16h 29, Dec 26o 26’)

The answer is a. I am missing why it's a.

Here is what I thought so far, full moon means the moon is the on the other side of the Sun, so the star is occulted near midnight locally.

Now it's Dec 23rd, so it's ahead of vernal equinox by 6 hours, i.e. the RA of the Sun is 18 h, being opposite to the Sun, the moon/star's RA should be close to 6h. 4h37m is 1.5h away, okayish ? since we are given a range of longitude where this occultation can be seen from britain to japan. However this doesn't rule out Pollux.

Also tried using Japan's latitude 36N, local hour angle = 65^o(?) and declination 16.5^o in a combined way but really can't see how this affect the solution.

Thanks,

 

[haruspex]

the moon is the on the other side of the Sun

I hope you mean on the other side from the sun.

so the star is occulted near midnight locally.

At what time would you see a full moon rise?

 

[WernerQH]

Now it's Dec 23rd, so it's ahead of vernal equinox by 6 hours, i.e. the RA of the Sun is 18 h, being opposite to the Sun, the moon/star's RA should be close to 6h. 4h37m is 1.5h away, okayish ?

Roughly, how many degrees does the Sun (and the anti-solar point) move every day? And in which direction? How far does the Moon move in two days? And in which direction?