2017 April 4

Comet C/2017 E4 (Lovejoy) much brighter than expected

Nick James

In addition to the two comets metioned in the observing challenge we have a third interesting object in the morning sky. This is comet C/2017 E4 (Lovejoy) discovered by Terry Lovejoy as recently as March 13. The comet is heading to perihelion on April 23 at a distance of 0.5 au from the Sun and it has been brightening more rapidly than expected. It is currently about 7th magnitude and shows a nice ion tail. The comet is currently in Pegasus and it is around 15 deg up at the start of twilight in the eastern morning sky. Throughout April it skirts around the NE horizon at dawn as shown in this chart (E4 Lovejoy.pdf).

Those at the BAA Winchester meeting next Saturday may want to get up well before breakfast and take advantage of the good NE horizon at Sparsholt in the hope of seeing or imaging the comet. At around 03:30 UT (04:30 BST) the gibbous Moon will be setting in the west and the comet will be around 15 deg up in the east as the dawn sky brightens. The Moon becomes more of a problem in the following week as it moves into the morning sky but it is new on April 26. By perihelion on April 23 the comet is in Andromeda not far from M31. On that day at 03:00 UT (04:00 BST) the comet will be around 12 deg up in the NE sky, around 5 deg below M31 and the thin crescent moon will not yet have risen.

As always it is difficult to predict how bright this comet will be but it is definitely one to keep an eye on. Recent images will be found in the Comet Section archive.