June 2021 – What’s Up!

Week of 28th June

• Astronomical twilight does not end until 00:55 BST on 21st July
• Watch the planets Venus (mag -3.9) and Mars (+1.8) appear ever closer to eachother through this week in our evening sky. Look to the western horizon to see the pair just after sunset
• The waning gibbous Moon passes by both Saturn (mag +0.4) and Jupiter (-2.6) on Monday and Tuesday. Look southeast, just above the horizon around 00:00 BST to see the solar system objects
• Mercury reaches greatest elongation west on Sunday, appearing with 21.6° separation from the Sun in the morning sky just before sunrise
• The Moon is Last Quarter on Thursday
• The Sun currently has one active region, AR 2835. The sunspot number is 16
• There are no visible evening ISS passes this week

Week of 21st June

• Astronomical twilight does not end until 00:55 BST on 21st July
• The Summer Solstice occurs at 04:25 BST on Monday, when the Sun will be at its most Northerly point in the sky with a declination of +23.5°. It will have an altitude of 62° at 13:00 BST, its highest point in the sky of the year. Monday will be the longest day of the year for us in the Northern Hemisphere and Monday night the shortest night, with only 7 hours 21 minutes between sunset and sunrise. The rising and setting of the Sun are also at their most northerly point of the year, with sunrise on Monday happening at an azimuth of just 49°, compare this with sunrise on the Winter Solstice at an azimuth of 128°!
• On Wednesday, Mars (mag +1.8) will be in conjunction with M44 the Beehive Cluster in Cancer. Look to the north-northwest horizon after sunset to find the planet and cluster. Venus (-3.9) will be just a few degrees further west
• The Moon is Full on Thursday – the Strawberry Moon (nothing to do with its colour, but so named as it indicates the time of year to gather ripening fruit)
• The Sun currently has one active region, AR 2833. The sunspot number is 15
• There are no visible evening ISS passes this week

Week of 14th June

• Astronomical twilight does not end until 00:55 BST on 21st July
• The Milky Way is well placed for observation this week as it rises higher in our evening sky. Use a pair of binoculars to take in the wealth of stars and dusty regions along the visible disc of our galaxy. Try to find the ‘Coathanger’ asterism in Vulpecula by first locating the wonderful double star Albireo, the beak of Cygnus, and then move a few degrees southwest to spot the upside down coathanger pattern of stars
• The gas giants Saturn and Jupiter are returning to our evening skies now, with Saturn rising at 23:57 BST at magnitude +0.5 and Jupiter following a little later at 00:42 BST, shining at mag -2.5
• The Moon is First Quarter on Friday
• The Sun currently has one active region, AR 2833, emerging around the oncoming mid-latitude northern hemisphere limb
• There are no visible evening ISS passes this week

Week of 7th June

• Astronomical twilight does not end until 00:55 BST on 21st July
• There is a solar eclipse on Thursday, appearing as an annular eclipse to those in Canada and Greenland, while it will be a partial eclipse for us here in Marlborough. First contact is at 10:06 BST, with maximum eclipse at 11:11 BST, when about 21% of the Sun will be obscured by the Moon. Last contact is at 12:20 BST. Hopefully the weather will allow a live stream to be broadcast. Take great care if trying to observe the partial eclipse yourself
• The Arietid meteor shower peaks on Thursday at around 15:00 BST. This is during daylight hours, so whilst meteors won’t be seen by eye, the radio meteor detector should see an increase in activity – watch the live stream to observe meteors in broad daylight!
• The Moon is New on Thursday
• The Sun currently has two active regions, AR 2827 and AR 2829. The sunspot number is 30. There has been a significant increase in solar activity so far this year, with only 29% of days being spotless. Compare this with 57% spotless days in 2020 and 77% spotless days in 2019
• There are no visible evening ISS passes this week