Night sky guide for October 2015

Newly discovered comet C/2013 US10 Catalina may reach naked eye visibility on October 1, 2015; it will continue to brighten and could reach magnitude 5 by November 6. 

Draconid meteor shower is scheduled to peak on October 8 with only about 10 meteors per hour. The second quarter moon will block out all but the brightest meteors this year. 

The Orionids, an average meteor shower producing up to 20 meteors per hour at its peak, is scheduled for the night of October 21 and the morning of October 22. This shower is produced by dust grains left behind by comet Halley, which has been known and observed since ancient times. The first quarter moon will set shortly after midnight leaving fairly dark skies for what should be a good show.

The last of three supermoons for 2015 falls on October 27. This event is followed by a rare 3-planet conjunction (Venus – Mars – Jupiter) visible on the morning of October 28.

• October 1 – M110 well placed for observations. M110, the brightest satellite galaxy of the Andromeda galaxy (M31), will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +41°40', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 28°S. At magnitude 8.0, M110 is visible through a pair of binoculars or a small telescope.

• October 1 – Comet C/2013 US10 Catalina. Newly discovered comet C/2013 US10 Catalina may reach naked eye visibility. The comet will continue to brighten and could reach magnitude 5 by November 6.

• October 2 – M31 well placed for observation. The Andromeda galaxy (M31) will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +41°16', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 28°S. M31 will be visible through a pair of binoculars or a small telescope.

• October 2 – M32 well placed for observation. M32, the second brightest satellite galaxy of the Andromeda galaxy (M31) after M110, will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +40°52', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 29°S. M32 will not be visible to the naked eye. You will need binoculars or a small telescope.

• October 3 – Asteroid 15 Eunomia well placed for observation. Asteroid 15 Eunomia will be well placed for observation, lying in the constellation Pegasus, well above the horizon for much of the night. Regardless of your location on the Earth, 15 Eunomia will reach its highest point in the sky at around midnight local time. You will need a telescope of moderate aperture and a good star chart to spot this asteroid.

• October 4 – Small Magellanic Cloud (SMC) well placed for observation. Across much of the world the Milky Way's dwarf companion, the Small Magellanic Cloud (SMC), in Tucana, will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of -72°48', it is easiest to see from the southern hemisphere and cannot be seen from latitudes much north of 2°S. At magnitude 2.7, SMC is visible to the naked eye, but best viewed through a pair of binoculars.

• October 8 – Draconid meteor shower. This is a minor meteor shower producing only about 10 meteors per hour. It is produced by dust grains left behind by comet 21P Giacobini-Zinner, which was first discovered in 1900. It is an unusual shower in that the best viewing is in the early evening instead of early morning like most other showers. The second quarter moon will block out all but the brightest meteors this year.

• October 8 – Conjunction between the Moon and Venus. The Moon and Venus will make a close approach, passing within 0°39' of each other. At the moment of closest approach, the Moon will be at mag -10.5, and Venus at mag -5.3, both in the constellation Leo. They will be a little too widely separated to fit comfortably within the field of view of a telescope, but will be visible to the naked eye or a through pair of binoculars.

• October 9 – Conjunction between the Moon and Mars. The Moon and Mars will make a close approach, passing within 3°16' of each other. At the moment of closest approach, the Moon will be at mag -10.0 in the constellation Sextans, and Mars at mag 1.5 in the neighboring constellation of Leo. The pair will be too widely separated to fit within the field of view of a telescope, but will be visible to the naked eye or through a pair of binoculars.

• October 12 – Uranus at opposition. Uranus will be well placed for observation, in the constellation Pisces. It will be visible for much of the night, reaching its highest point in the sky at around midnight local time. Due to its distance, it will only appear as a tiny blue-green dot in all but the most powerful telescopes.

• October 12 – Comet 22P/Kopff reaches its brightest. Comet 22P/Kopff is forecast to reach its brightest, at around mag 11.5. It will lie at a distance of 1.56 AU from the Sun, and at a distance of 2.03 AU from the Earth.

• October 13 – New Moon – 00:06 UTC. The Moon will pass close to the Sun and become lost in the Sun's glare for a few days. At new moon, the Earth, Moon and Sun all lie in a roughly straight line, with the Moon in the middle, appearing in front of the Sun's glare. In this configuration, we see almost exactly the opposite half of the Moon to that which is illuminated by the Sun, making it doubly unobservable because the side we see is almost entirely unilluminated.

• October 15 – M33 well placed for observation. The Triangulum galaxy (M33) will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +30°39', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 39°S. At magnitude 5.7, M33 is too faint to be seen with the naked eye from any but the very darkest sites, but is visible through a pair of binoculars or small telescope.

• October 16 – Mercury at greatest elongation west. Mercury will be well placed for observation in the dawn sky, shining brightly at mag -2.6. Over coming weeks, the distance between Mercury and the Sun will decrease each morning.

• October 16 – Conjunction between the Moon and Saturn. The Moon and Saturn will make a close approach, passing within 2°54' of each other. At the moment of closest approach, the Moon will be at mag -10.2 in the constellation Scorpius, and Saturn at mag 1.2 in the neighboring constellation of Libra. They will be too widely separated to fit within the field of view of a telescope, but will be visible to the naked eye or through a pair of binoculars.

• October 17 – Conjunction between Jupiter and Mars. Jupiter and Mars will make a close approach, passing within 0°22' of each other. At the moment of closest approach, Jupiter will be at mag -1.8, and Mars at mag 1.5, both in the constellation Leo. At closest approach, the pair will be close enough to fit comfortably within the field of view of a telescope, but will also be visible to the naked eye or a through pair of binoculars.

• October 21, 22 – Orionid meteor shower. This is an average shower producing up to 20 meteors per hour at its peak produced by dust grains left behind by comet Halley, which has been known and observed since ancient times. It peaks this year on the night of October 21 and the morning of October 22. The first quarter moon will set shortly after midnight leaving fairly dark skies for what should be a good show. 

• October 25 – Asteroid 29 Amphitrite at opposition. Asteroid 29 Amphitrite will be well placed for observation, lying in the constellation Aries, well above the horizon for much of the night. Regardless of your location on the Earth, 29 Amphitrite will reach its highest point in the sky at around midnight local time.

• October 25 – Conjunction between Venus and Jupiter. Venus and Jupiter will make a close approach, passing within 1°01' of each other. At the moment of closest approach, Venus will be at mag -5.1, and Jupiter at mag -1.8, both in the constellation Leo. They will be too widely separated to fit within the field of view of a telescope, but will be visible to the naked eye or through a pair of binoculars.

• October 26 – Venus at greatest elongation west. Venus will be well placed for observation in the dawn sky, shining brightly at mag -5.1.  Look for the bright planet in the eastern sky before sunrise.

• October 26 – Conjunction between the Moon and Uranus. The Moon and Uranus will make a close approach, passing within 0°52' of each other. At the moment of closest approach, the Moon will be at mag -12.8, and Uranus at mag 5.7, both in the constellation Pisces.

• October 27 – Full moon, supermoon – 12:05 UTC. The Moon will be located on the opposite side of the Earth as the Sun and its face will be will be fully illuminated. This full moon was known by early Native American tribes as the Full Hunters Moon because at this time of year the leaves are falling and the game is fat and ready to hunt. This moon has also been known as the Travel Moon and the Blood Moon. This is also the last of three supermoons for 2015. The Moon will be at its closest approach to the Earth and may look slightly larger and brighter than usual.

• October 27 – NGC 884 well placed for observation. The open star cluster NGC 884 in Perseus, also known as the eastern half of the double cluster, will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +57°07', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 12°S. At magnitude 4.0, NGC884 is tricky to make out with the naked eye except from a dark site, but is visible through a pair of binoculars or small telescope.

• October 28 – Conjunction of Venus, Mars, and Jupiter. A rare, 3-planet conjunction will be visible on the morning of October 28. The planets Venus, Mars, and Jupiter will all form a tight 1-degree triangle in the early morning sky. Look to the east just before sunrise for this spectacular event.

Video courtesy of Hubble Space Telescope

Sources: InTheSky (Dominic Ford), SeaSky

Featured image credit: SolarSystemScope. Edit: TW.