The comet 123P/West-Hartley
From Ashburn , 123P/West-Hartley will become visible around 21:46 (EDT) as the dusk sky fades, 22° above your western horizon. It will then sink towards the horizon, setting 3 hours and 18 minutes after the Sun at 23:47.
Object Type Comet
|Right Ascension:||12h29m |
22.52 lightmin 
|Absolute Mag (V):||44.94|
|Semi-major axis:||3.86 AU|
|Longitude ascending node:||46.50°|
|Argument of perihelion:||103.01°|
|Epoch of elements:||14 May 2019|
|Mean Anomaly at epoch:||12.73°|
|Orbital period:||7.58 years|
Where possible, the brightnesses of comets are estimated from absolute magnitude values computed by the BAA Comet Section, based on the observations they receive. We prefer these to the Minor Planet Center's own magnitude estimates, since the latter are less often updated. Nonetheless, comets are intrinsically unpredictable objects, and magnitude estimates must always be taken with a pinch of salt.