CDAA

Written by David Pugh

Dear CDAA Members

I hope that you are all well and have so far avoided this latest Covid strain. Firstly, a reminder that next Thursday July 4th at 7.30pm guest speaker Jerry Workman will be giving us a talk on our nearest neighbour - the Moon. Hope to see you there.

As for the night sky for July, as we are now past the summer solstice the nights will start to draw in with astronomical darkness starting to appear again by the third week of the month. In terms of observing the planets the situation is gradually improving from a poor showing this year up to now.

The innermost planet Mercury, despite reaching greatest elongation from the Sun, is poorly placed in the early evening for viewing from the UK setting an hour after sunset.. Venus, following last month's superior conjunction, is still too close to the Sun to observe this month. Mars, at mag +1.0 is a pre-dawn object in Taurus rising nearly 3 hours before sunrise on 1 July. By the end of the month it rises just before midnight. On July 21 Mars is in conjunction with the Pleiades, lying 4.8 degrees south of the cluster.

Jupiter, at mag -2.1, dominates the pre-dawn sky also in Taurus. It becomes a conspicuous object in the east before dawn by the end of the month, not far from the Pleiades. On July 4 Jupiter lies 5 degrees north of Aldebaran and by the end of July Mars will have moved to only 7 degrees west of Jupiter, having moved north of the Hyades cluster. The beautiful ringed planet Saturn (mag +0.8) lies in NE Aquarius, rising about midnight as July begins. By July 31 Saturn appears at its highest altitude of 30 degrees due south.

Uranus (mag +5.8) is a pre-dawn object in Taurus. Despite its low altitude in the pre-dawn sky a pair of binoculars should show it. On the morning of July 15 it will be only 39 arc minutes from Mars, both planets lying 6 degrees SSW of the Pleiades. This is a good photo opportunity for anyone up in the early hours but you will need a flat NE horizon. Finally we have the ice giant Neptune (mag +7.9) in Pisces as another pre-dawn object. Its position improves through July, reaching an altitude of 30 degrees by month's end. Again another binocular object or observable with a telescope if you wish to try for its tiny bluish disc.

On July 1 to 4th and again on July 30 and 31 the pre-dawn eastern sky in Taurus will be joined by the crescent Moon, adding to the spectacle of Jupiter, Mars and Uranus with the Pleiades and Hyades clusters.

Beyond the solar system I have been keeping an eye on the area of T Corona Borealis with binoculars when it is clear but nothing is happening yet with this famous recurrent nova. Both Hercules and Ophiuchus and their globular star clusters covered in last month's Night Sky Watch are still well placed for observing but I would like to go further south this month. So for the following deep sky objects you need a good southern aspect. Preferably go for each object when they are due south and therefore at their highest point above the horizon.

Firstly, if you can see the bright first magnitude red giant star Antares in Scorpius, 12 degrees above the southern horizon at best, you should also be able to observe with binoculars or a telescope the globular cluster M4 mag 5.4 and diameter 36' lying only a little over one degree to the west. Then moving further east to Sagittarius try for M22 the third best globular cluster in the whole sky. At mag 5.2 and 32' diameter it looks like the nucleus of a comet in binoculars. Elsewhere Sagittarius is rich in nebulae. Whilst at their low UK altitude you probably won't see the nebulae visually due to the dimming effects of light pollution, you could see their central star clusters. Moreover I can attest that you can image these nebulae from Clacton, especially if you have a light pollution filter.

Firstly, at Declination -24 degrees and therefore reaching 14 degrees high at best you have M8 the famous Lagoon Nebula with its young cluster NGC 6530. Then only a degree to it's north you have the Triffid Nebula M20 easily in the same field of view in a low power eyepiece or using binoculars. Further north still you have the Swan or Omega Nebula M17 and, over the border into Serpens Cauda, about 2 degrees NNW of M17 you have the Eagle Nebula M16. The core of this nebula is the famous HST "Pillars of Creation" elephant's trunk structures where new stars are forming. This nebula and associated cluster reaches a comfortable 24 degrees above our southern horizon.

However, if this is still too low for you let's end with two objects much higher in the July sky. Firstly, the famous Ring Nebula M57 planetary nebula in Lyra (mag 8.8), not far from bright star Vega, is well worth a look with a telescope but at only 65" diameter you will get a better view at higher powers of this "smoke ring" in the sky.. Finally, nearby, also in Lyra there is the small globular cluster M56 mag 8.3 dia 7' to try for.

Good Hunting. Hope to see you Thursday evening.

Best Regards

David