Read our September sky notes to find out what’s in the night sky this month!
Map
Constellations
These constellations are well placed in the evening this month, but many more can be seen. Check the star map for more.
Pegasus appears low on the eastern horizon this month, before moving across the southern sky towards the west in the early hours of the morning. The best view will be around 02:00 BST at the beginning of the month when it is highest in the sky, getting earlier as the month goes on. You can identify Pegasus by the Great Square of Pegasus, a summer asterism that forms the main body of the constellation.
Cygnus the Swan is a circumpolar constellation and is therefore visible all night. It appears high in the eastern sky at sunset and gets lower towards the west in the morning. It appears around the zenith early in the evening and so will be best visible at that time. Cygnus contains the asterism The Northern Cross, the top of which contains its brightest star Deneb.
Aquila the Eagle appears at sunset in the south and lowers towards the west over the course of the night before setting a little before dawn. Look for the brightest star, Altair, forming the top of the constellation.
Planets
Mercury is close to the Sun this month and not visible most of the month. It can only be seen immediately before dawn at the end of the month, but will be very low in the east and only visible with a clear horizon. Mercury is at greatest elongation west and dichotomy on the 22nd and highest altitude on the 23rd.
Venus can be seen in the morning sky this month, rising in the east a little before sunrise and disappearing in the morning sky. It rises earlier as the month goes on, so best views will be towards the end of the month, when it reaches its highest point. Venus will be at its greatest brightness on the 18th.
Mars is too close to the Sun to be seen this month.
Jupiter is visible for most of the night this month, rising in the north east and climbing higher towards the southern sky before disappearing at dawn. Best views will be just before sunrise, but it will rise earlier towards the end of the month and so can be seen low on the horizon in the evening. Jupiter will enter retrograde motion on the 4th and will also be in conjunction with the Moon on the 4th.
Saturn appears low on the south east horizon at sunset and moves across the southern sky to set in the west. At the beginning of the month it sets at sunrise, but the Sun rises a little later as the month goes on, meaning Saturn sets a couple of hours before dawn at the end of the month. It will be in conjunction with the Moon on the 27th.
Uranus is too faint to be seen with the naked eye. It rises after sunset and climbs high in the south before disappearing at dawn. At the beginning of the month, it rises a couple of hours after the Sun, but this gap narrows over the course of the month. Best views will be at the beginning of the month just before dawn, when it is highest in the sky.
Neptune is too faint to be seen with the naked eye. It appears on the south eastern horizon at sunset, moving across the sky to set in the west at dawn. Neptune begins the night lower in the sky as the month continues, so can be better seen in the morning sky towards the end of the month as it will not fully set before the sun rises. It will undergo lunar occultation on the 1st and opposition on the 19th.
Meteor Showers
The Aurigids reach their peak on the 1st. The radiant (apparent origin point of the meteors) will be in the constellation of Auriga. As this is a circumpolar constellation, meteors will be visible all night. Best views will be just before dawn, as the radiant reaches its highest point after dawn. You will be able to see about 5 meteors per hour.
The September ε-Perseids reach their peak on the 10th. The radiant (apparent origin point of the meteors) will be in the constellation of Perseus. This is a circumpolar constellation, so meteors will be visible all night. Best views will be just before dawn, as Perseus reaches its highest point after sunrise. You will be able to see about 4 meteors per hour.
The Daytime Sextantids will reach their peak on the 28th. The radiant (apparent origin point of the meteors) will be in the constellation of Sextans. Meteors are only visible when the radiant is in the sky, so you will only be able to see them from 04:38 BST until dawn. Best displays will be just before dawn, as the radiant reaches its highest point in the daytime. The radiant is particularly low in darkness hours, so only 1 meteor per hour will be visible.
Moon
Last Quarter: 6th
New Moon: 15th
First Quarter: 22nd
Full Moon: 29th
The Moon reaches perigee, its closest point to the Earth, on the 28th and apogee, its furthest point, on the 12th. This effect is not visually apparent.
The Moon will be at perihelion, its closest point to the Sun, on the 17th & 23rd and aphelion, its furthest point, on the 27th. This effect is not visually apparent.
Points of Interest
The September Equinox, where the day and night are of equal length, takes place on the 23rd.
Visit Spot the Station to find out when the ISS will be visible from your location.
Last updated: 23rd August.