(Please note all times are ST and are based on an observing location of Belfast and covers the month of August)
At the start of the month, the Sun rises at 05:35 and sets at 21:20. By month's end, it rises at 06:30 and sets at 20:15.
There is partial solar eclipse on the evening of the 21st. The approx. details are that the eclipse will start at 19:39 and end at 20:23 (Sunset is 20:40). At its peak 9% of the sun's disk will be covered by the moon. As it is a partial eclipse, IF YOU WISH TO OBSERVE IT YOU MUST USE PROPER SOLAR ECLIPSE GLASSES or ASTRO GEAR WHICH IS SPECIFICALLY DESIGNED FOR VIEWING THE SUN SAFELY.
Mercury is at inferior conjunction on the 26th and is not visible this month.
Venus is a morning object in August. It rises at 02:30 at the start of the month, by month’s end it rises at 03:25. It fades from mag -3.9 to mag -3.8 during the month.
Mars is not visible this month.
Jupiter is visible in the evening sky this month in Virgo. During the month, it is visible as soon as darkness falls and sets at 21:20 by month’s end. It fades from mag -1.7 to mag -1.6 during the month.
Saturn is visible this month in Ophiuchus. During the month, it is visible as soon as darkness falls and sets at 23:45 by month’s end. It fades from mag +0.3 to mag +0.4 during the month.
Uranus becomes visible in the evening sky this month in Pisces. At the start of the month, it rises at 23:30, by month’s end it rises at 21:30. It brightens from mag +5.8 to mag +5.7 and lies near to Torcularis Septentrionalis (Omicron (ο) Piscium, mag +4.3) during the month.
Neptune is visible in the evening sky this month in Aquarius. At the start of the month, it rises at 22:25 and by month’s end it rises at 20:25. It maintains its brightness at mag +7.8 and lies near to Lambda (λ) Aquarii, mag +3.7 during the month.
The full moon on the 7th (19:10). The last quarter moon is on the 15th (02:15) with the new moon on the 21st (19:30). The first quarter moon is on the 29th (09:13).
There is a penumbral lunar eclipse on the evening of the 7th. The moon rises at 21:00 while still in the Earth’s outer shadow (penumbra) and the eclipse finishes at 21:50. This will lack the wow factor of a total lunar eclipse, but may still be worth a look.
There is a daytime lunar occultation of Aldebaran (Alpha (α) Tauri, mag +0.9) on the 16th between the times of 07:30 and 08:40 approximately.
1st pm the waxing gibbous lies NW of Antares (Alpha (α) Scorpii, mag +1.0) at 23:00.
2nd pm the waxing gibbous lies NE of Antares (Alpha (α) Scorpii, mag +1.0) and NW of Saturn at 23:00.
3rd pm the waxing gibbous lies NE of Saturn at 23:00.
9th pm the waning gibbous lies SW of Neptune at 23:00.
13th am the waning gibbous lies SW of Uranus at 00:00.
16th am the waning crescent lies NW of Aldebaran (Alpha (α) Tauri, mag +0.9) at 02:00.
19th am the waning crescent lies SW of Venus at 04:00.
25th pm the waxing crescent lies NE of Jupiter and NW of Spica (Alpha (α) Virginis, mag +1.0) at 21:00.
29th pm the waxing gibbous lies N of Antares (Alpha (α) Scorpii, mag +1.0) and NW of Saturn at 21:00.
30th pm the waxing gibbous lies NE of Saturn at 21:00.
The best time to observe meteor showers is when the moon is below the horizon; otherwise its bright glare limits the number you will see especially the fainter ones. Below is a guide to this month's showers.
The Perseids peak on the night of 12th/13th with a ZHR of 150. The radiant is visible as soon as darkness falls on the evening of the 12th, but a waning gibbous moon rises at 23:05 in Pisces on the same evening, so you get roughly 2 hours after sunset to spot any meteors before the moon spoils the view.
There may be additional minor showers this month, details of which can be found in the below Information Sources and Links Section.
There are no bright asteroids at opposition this month.
Finder charts and further information about other fainter asteroids can be found in the below Information Sources and Links Section.
Comet C/2015 ER61 (PanSTARRS) is currently mag +9 and fading. This month, it will be in Taurus. At the start of the month, it will be visible from around 03:00, by month’s end it will be visible from around 01:00. Between the 15th and the 22nd, it passes South of M45- The Pleiades and this well-known object can be used to locate the comet.
Finder charts and further information about the above and other fainter comets can be found in the below Information Sources and Links Section. Any of the above estimates are based on current information at the time of writing the guide and can be wrong - “Comets are like cats; they have tails, and they do precisely what they want”, David H Levy.
On the deep sky front this month, galaxies M81 and M82 can be observed in Ursa Major. Check out the constellation Canes Venatici with the globular cluster - M3 and several galaxies including M51 - the Whirlpool Galaxy and M63 - the Sunflower Galaxy. In Hercules, two globular clusters - M92 and the excellent M13 can be observed and in Lyra - M57 - The Ring Nebula can be observed. In Vulpecula - M27 - The Dumbbell Nebula can be found. In Andromeda, M31 - The Andromeda galaxy can be observed along with its satellite galaxies M32 and M110. In Perseus, there is the open cluster M34 and the excellent Double Cluster. Finally in Triangulum, there is the galaxy M33.
Always keep an eye out for Aurorae. We have the return to dark skies in August with Astronomical twilight no longer dominating the night.
Watch out for NLCs - Noctilucent Clouds during the first half of August. Look to the North-West for a white/silvery glow 1.5 - 2 hours after sunset and to the North-East a similar amount of time before sunrise. They can sometimes be faint, sometimes bright. Other interesting naked eye phenomena to look out for include the Zodiacal Light and the Gegenschein. Both are caused by sunlight reflecting off dust particles which are present in the solar system.
The Zodiacal Light can be seen in the West after evening twilight has disappeared or in the East before the morning twilight. The best time of year to see the phenomenon is late-Feb to early-April in the evening sky and September/October in the morning sky - it's then that the ecliptic, along which the cone of the zodiacal light lies, is steepest in our skies. The Gegenschein can be seen in the area of the sky opposite the sun. To view either, you must get yourself to a very dark site to cut out the light pollution. When trying to observe either of these phenomena, it is best to do so when the moon is below the horizon. A new appendix has been added explaining some of the more technical terms used in the guide.
The ZHR or Zenithal Hourly Rate is the number of meteors an observer would see in one hour under a clear, dark sky with a limiting apparent magnitude of 6.5 and if the radiant of the shower were in the zenith. The rate that can effectively be seen is nearly always lower and decreases as the radiant is closer to the horizon. The Zenith is the overhead point in the sky.