The comet 123P/West-Hartley
From Washington , 123P/West-Hartley will become visible at around 22:13 (MDT) as the dusk sky fades, 39° above your south-western horizon. It will then sink towards the horizon, setting 4 hours and 45 minutes after the Sun at 01:41.
Object Type Comet
|Right Ascension:||11h53m |
19.29 lightmin 
|Absolute Mag (V):||44.66|
|Semi-major axis:||3.86 AU|
|Longitude ascending node:||46.50°|
|Argument of perihelion:||103.02°|
|Epoch of elements:||13 May 2019|
|Mean Anomaly at epoch:||12.73°|
|Orbital period:||7.58 years|
|Light-on-dark||PNG image||PDF document|
|Dark-on-light||PNG image||PDF document|
Magnitudes estimates are derived from observations sent into the BAA Comet Section, as compiled by Jonathan Shanklin and last updated on 3 June 2019. We use these amateur observations in preference to the MPC's magnitude estimates, since they are updated much more often. Nonetheless, all comets are intrinsically unpredictable objects, and future magnitude estimates must always be taken with a pinch of salt.