We reached the autumnal equinox on the 23rd last month and so the nights are distinctly longer. This is the time of year when the nights draw in at their fastest. Make the most of the darker nights.
Planets
Mercury
Mercury passed through superior conjunction at the end of August and becomes an evening object. However, the ecliptic near it is well south of the celestial equator meaning that Mercury is very low in the sky and hard to detect, despite reaching greatest elongation of +25deg, meaning that it sets shortly after sunset.
Venus
Venus passes through Inferior Conjunction (Between Earth and Sun) on the 24th October and so is not observable this month.
Mars
Mars remains a largely morning but does rise around midnight (BST) in Cancer, near Praesepe and a little west of Jupiter. With a diameter of 6.5 arcsec and magnitude 1.0, it is still small. Best to wait until later in the year.
Jupiter
Jupiter now rises a little after midnight and so is still a morning object, lying just west of the sickle of Leo. It is worth getting up for!
Saturn
Saturn reaches opposition on the 4th October, and so is observable throughout the night. It rises around 18 hrs UT. It is magnitude 0.4 and lies to the south-east the square of Pegasus. The rings are open to about 7deg, and therefore more noticeable.
Uranus
Uranus is easier to observe late evening in Taurus, near the Hyades, but rises around 20 hrs UT. Its coordinates are RA: 4h 10m, Dec: +20.9. It is magnitude 5.6 with a diameter of 3.8” (arcsec). It should appear as a tiny bluish disc.
Neptune
Neptune reached opposition at the end of September and is now visible throughout the night. It lies below the square of Pegasus, a little west of Saturn.
Magnitude 7.8 and diameter 2.4”. RA: 0h 13m, Dec: -0 35’
Moon Phases:
| 3rd October: Last Quarter | 10th October: New Moon |
| 18th October: First Quarter | 26th October: Full Moon |
Lunar Occultation:
On the 28th October, the Moon passes through the Pleiades and occults several stars. This could be a great photographic opportunity!
Meteor Showers
The Orionid meteor shower occurs throughout the month, reaching its peak on the 21st. The Zenithal Hourly Rate (ZHR) is normally only about 20, but displays do vary. Moonlight will not be a major problem, especially late in the night. Quite favourable.
Sun
We remain near solar maximum, so watch out for major sunspots and sunspot groups. Remember to never look at the Sun directly without a proper solar filter.
Aurora
The Sun remains active, so keep a watch out for aurorae now that the skies are darker much earlier. I recommend one of the many Apps that can warn you of aurorae.
Deep Sky Objects
The evenings are getting dark much earlier, making deep sky observing much easier now. The Milky Way will be visible high in the sky, although the core is not visible. Try to get to a dark site if you want to see it well or get a decent photograph. Cygnus is still well placed as well.
The Andromeda Galaxy is well placed. The M13 and M92 globular clusters in Hercules are still accessible and good objects for binoculars, small telescopes or astrophotography. The Perseus Double Cluster is another very rewarding sight, both in binoculars and for astrophotography. M57, the Ring Nebula in Lyra is a good object, as well as M27, the Dumbbell Nebula in Vulpecula. The region of Cygnus is rich in deep sky objects. The Pleiades are getting well placed for observing and photographing. Also, don’t miss the lunar occultation of the Pleiades on the 28th.
Neil Havard.