The Night Sky in October 2024
The nights are certainly drawing in and getting longer. Don’t forget to set your clocks back on 27th October, though for many of us in this digital age this is done automatically.
When sextant star sightings were use to work our position the observations were always with respects to GMT, the time measured at Greenwich Meridian. The ship chronometer was never wound backward as that could affect its accuracy in the process. Even today RN ships and submarines on operational duties still refer event to Zulu time, which in effect is GMT.
For more information on the changing of clocks see:
However long nights mean the telescopes, binoculars and Mk1 eyeball can be used earlier and constellations I consider old friends become visible earlier.
The website https://binocularsky.com/ publishes excellent star maps each month which are easy to use with binoculars and small telescopes.
The Moon
This month it is termed the Hunters Moon, reflecting life long before refrigeration when meat for the winter had to be caught, butchered and preserved for the winter ahead.
In North America the First Nation peoples called it the Leaf Falling Moon and also the White Frost on the Grass Moon.
The Moon will start to be visible on 4th October and reach full phase on the 17th.
Of note this month and easy to see will be a Lunar occultation of part of the southern section of the Pleiades, starting at 20:20 BST on 19th October. Ending at 21:30 BST. The Moon will be 91% waning, so bright, but a low F telescope or a pair of binoculars should allow you to see this event.
The Planets
Mercury: Is not well laced to see from Norfolk. It is low in the wet after sunset and only reaches an altitude of about 15 ˚ on the 21st October.
Venus
Will be too low in the sky for observing
Mars
Reaches quadrature on the 14th October and shows a gibbous phase. Just to explain what quadrature and other terms like opposition etc mean please see the diagram below.
Also see https://en.wikipedia.org/wiki/Opposition_%28astronomy%2
Jupiter: Starts retrograde motion from 6th October onwards, it then reaches opposition in 17 weeks time around January 2025 when it should display even better views. Jupiter, even in small telescopes and binocular present an ever changing display as its four brightGalilean moons rotate around iLarger telescopes will show more band details and even shadow transits of the larger four moons across the gaseous surface.
Saturn: Saturn too is in retrograde motion, shining at magnitude 1 in Aquarius and is visible now most of the night. The rings are now starting to be visible again, in June they were almost edge on. I result of its inclined orbit with respect to Earth. It reaches its highest altitude of 30˚ at the end of October.
Its largest moon Titan can be seejust 6 arc seconds below the south pole of Saturn on 3rd October at 22:00 BST, 21:00 UT.
Uranus: Another planet in retrograde motion to be found in Taurus. At +5.5 mag it can be found about 5˚ south of the Pleiades in the early morning.
Neptune: Can be seen between Cetus and Pisces soon after dark. It is about 35˚ altitude.
Meteors
This month the Orionid meteor shower will be seen at best around 21st-22nd October. Usually the best seeing is after midnight as that is when our portion of the Earth’s globe is pointing towards the direction of our orbit increasing the chances of seeing meters. It is also well after Full Moon making the skies darker. The origin point is actually between Orion and Gemini.
See for even more detail Orionid meteor shower 2024: All you need to know (earthsky.org)
Comets: The comet C/2023 A3 Tsuchinshan is promising to be a naked eye object from 19th October onwards, but you will need a clearer horizon towards the west. See Comet C/2023 A3 (Tsuchinshan-ATLAS) | TheSkyLive to follow, this ids an excellent website.
Constellation of the Month
To the east if you look up overhead you will see a W shaped constellation, this is Cassiopeia, it lies against the background of the Milky Way, as you drop down toward the horizon there is a slightly triangular formation with a head tail of starts pointing up to Cassiopeia, this is Perseus. In Greek mythology he has come to rescue her from the Kraken.
Halfway between the two is a double cluster of stars which look stunning in binoculars. This is the Perseus Double cluster, they are about 7,500 light years away, they are bright blue white and therefore young stars and ‘only’ 14 million years old. Double Cluster – Wikipedia
Go back down to the triangle of Perseus and down to the right the bottom star is called Algol, the winking star. This is many old star maps is the eye of Medusa who Perseus slew. The Arab astronomers called it Algol which means the winking star. It is actually an eclipsing binary star. A smaller less bright star is passing in front of its larger part net and the reduces its brightness. This cycle happens over just about three days. Algol – Wikipedia
Keep Looking Up!
Frank Dutton
