Bright comet for July

After two dismal comet failures this year, hopes are high for Comet C/2020 F3 (NEOWISE), which promises to be visible to the naked eye during July 2020.

This image, a stack of 13 exposures, was taken by Paul Sutherland on the morning of 6 July, with a Fujifilm X-T10 camera and 230mm lens, from Walmer, Kent.

The comet is due to make its way into the northern sky during the first week of July, and become visible in the late evening sky during the second half of the month. So far its brightness appears to be on track for naked-eye visibility, although this doesn’t mean that it will be spectacular. The best time to look for an early view, when it’s highest in the sky and the Sun is still well below the horizon, will be around 3 am BST, but by the second half of July it will also be a late evening object.

The thing about comets is that they brighten up as they get close to the Sun – so more often than not, this means that they are in a twilight sky. Even though its current brightness is around magnitude 2.5, which if it were a star would make it easily visible, because it’s a fuzzy blob it can easily be washed out by the brightness of the twilight sky.

By about the third week in July, however, it may still be fairly bright (around magnitude 4) but farther away from the Sun, so we get to see it in a darker sky. Even so, it might be more easily visible in binoculars than with the naked eye.

The good news is that the comet is moving to the north of the Sun, so here in the northern hemisphere we do have at least a chance to see the thing with the Sun below the northern horizon. And those living farther north in the UK are in a better position than those farther south.

Will it have a tail? Photos taken from more southerly latitudes on 3 July, the date of the comet’s closest approach to the Sun, do show a tail, so there is a good chance that this will really look like a classic comet rather than a fuzzy blob, as more run-of-the-mill comets tend to do. Observers also report seeing the comet and its tail with the naked eye.

Where to look

The comet will be in the northern sky, in fact just a bit to the west of north if you are viewing in the late evening. At this time of year the bright star Capella is low on the northern horizon, and it’ll act as a good guide to the comet’s position. For fainter comets we publish detailed charts showing you precisely where to look or to aim your telescope, but for the brighter objects (we hope) such as this one a more general sky view should be enough. Note the position of Capella, and search the area below it at the time specified. This chart is for the north of the UK, and from the south coast you might need to wait for a few more days to get a glimpse.

The view below shows where to look in the evening sky after about 10 July. For maps showing the positions for 3 am during the first week in July, and for more information from our Comet Section Director, Stuart Atkinson, see our comet news page.

Positions for Comet 2020 F3 Neowise for July 2020
Positions for Comet NEOWISE during July 2020, 11:30 pm BST

Members of the SPA will be out in force, eager for a glimpse of Comet NEOWISE, and sharing their views. If you’re not already a member too, then why not join now and join in the fun!

Please return here from time to time for photos of the comet as they come in.