Notes on the Comets of 2013


In 2013 there will be 2 significant comet events. In mid March C/2011 L4 PANSTARRS will reach it's maximum brightness (0.5) and in November C/2012 S1 ISON will reach a brightness of -5 on the 29th. It is early days yet to predict the visibilities and they are likely to change towards this time.

We will post here charts showing the paths but below are two links to tables of daily RA and Dec from the IAU pages for the two comets which I hope will be kept up to date:                     

Ephemeris for C/2011 L4 PANSTARRS

Ephemeris for C/2012 S1 ISON

Using Goto and finding comets

If you have a goto scope there is usually a facility to add your own objects. The Meade Autostar certainly has this feature and after looking at a copy of an online manual the Celestron NexStar controller also has this fearure. Consult your manual for full details.

Unlike stars, the moon and planets, comets do not follow a path that is coded into the controllers so use the following procedure.

Set up two new User Objects by following the instructions in the manual for your controller. If you bring your scopes to a meeting I would be glad to help. This is best done indoors in daylight.

On the day you intend to observe, lookup the RA and Dec for the intended observation from the tables linked above.

Edit the intended User Object's RA and Dec to the values for that day. Remember to estimate or calculate a conversion of seconds to tenths of a minute (for Autostar) or for the format for your controller. You will have to change this on every day that you intent to make an observation attempt.

Keep Fingers crossed for clear skies.

Align your scope as normal, then select your user object from the objects menu and hit GOTO. Use a wide angle, low power eyepiece and adjust when the object is in view. (Hopefully)

Happy Comet Hunting !