Night sky guide for April 2016

April hosts two meteor showers, but only one major. The first – Virginid meteor shower – will reach its maximum rate of activity on April 12. The Moon will be 5 days old and will present minimal interference. The maximum rate of meteors expected to be visible from a dark location is 5 per hour.

The second meteor shower of the month – Lyrids – will reach the maximum rate of activity on April 23. However, the Moon will be 16 days old, and being so close to Full Moon, will severely limit the observations  The maximum rate of meteors expected to be visible from a dark location is around 10 per hour. 

The best time of the month to observe faint objects such as galaxies and star clusters is April 7.

The Moon will reach full phase on April 22.

• April 1 – M104 well placed for observation. The sombrero galaxy (M104, NGC 4594) will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of -11°37', it is easiest to see from the southern hemisphere; it can be seen at latitudes between 58°N and 81°S. At magnitude 8.3, M104 is quite faint, and can not be seen by the naked eye, but can be viewed through a pair of binoculars or a small telescope.

• April 3 – M84 well placed for observation. M94, a spiral galaxy in Canes Venatici, 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°07', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 28°S. At magnitude 8.2, M94 is quite faint, and certainly not visible to the naked eye, but can be viewed through a pair of binoculars or a small telescope.

• April 4 – MGC 4755 well placed for observation. Across much of the world, the jewel box open star cluster (NGC 4755, also known as the kappa Crucis cluster) in Crux will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of -60°19', it is easiest to see from the southern hemisphere and cannot be seen from latitudes much north of 9°N. At magnitude 4.2, NGC4755 is tricky to make out with the naked eye except from a dark site but is visible through a pair of binoculars or a small telescope.

• April 4 – Comet 333P/LINEAR at perihelion. Comet 333P/LINEAR will make its closest approach to the Sun, at a distance of 1.11 AU.

• April 7 – New Moon – 11:24 UTC. The Moon will be located on the same side of the Earth as the Sun and will not be visible in the night sky. This is the best time of the month to observe faint objects such as galaxies and star clusters because there is no moonlight to interfere.

• April 10 – Comet 116P/Wild reaches its brightest. Comet 116P/Wild is forecast to reach its brightest, at around mag 12.6. It will lie at a distance of 2.28 AU from the Sun, and at a distance of 1.44 AU from the Earth.

• April 12 – Virginid meteor shower. The Virginid meteor shower will reach its maximum rate of activity on April 12, 2016. Some shooting stars associated with the shower are expected to be visible each night from April 7 do 18. The maximum rate of meteors expected to be visible from a dark location is around 5 per hour (ZHR). The Moon will be 5 days old at the time of peak activity, and so will present minimal interference. The best place to look to see as many meteors as possible is not at the radiant itself, but at any dark patch of sky which is around 90° away from it, since it is at a distance of around 90° from the radiant that meteors will typically appear at their brightest.

• April 12 – 136108 Haumea at opposition – 02:55 UTC. Dwarf planet 136108 Haumea will be well placed for observation, in the constellation Bootes. It will be visible for much of the night, reaching its highest point in the sky at around midnight local time. Over the weeks following its opposition, 136108 Haumea will reach its highest point in the sky four minutes earlier each night, gradually receding from the pre-dawn morning sky while remaining visible in the evening sky for a few months.

• April 12 – NGC 5128 well placed for observation. Across much of the world, Centaurus A (NGC 5128) will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of -43°01', it is easiest to see from the southern hemisphere and cannot be seen from latitudes much north of 26°N. At magnitude 7.0, NGC5128 is quite faint, and certainly not visible to the naked eye, but can be viewed through a pair of binoculars or a small telescope.

• April 13 – Omega Centauri well placed for observation. Across much of the world the brightest globular cluster in the sky, Omega Centauri, will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of -47°28', it is easiest to see from the southern hemisphere and cannot be seen from latitudes much north of 22°N. At magnitude 3.7, ω-Cen is tricky to make out with the naked eye except from a dark site but is visible through a pair of binoculars or a small telescope.

• April 13 – M51 well placed for observation. The whirlpool galaxy (M51, NGC 5194) will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +47°16', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 22°S. At magnitude 9.6, M51 is quite faint, and certainly not visible to the naked eye, but can be viewed through a pair of binoculars or a small telescope.

• April 15 – M83 well placed for observation. Across much of the world the southern pinwheel galaxy (M83, NGC 5236), a face-on spiral galaxy in Hydra, will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of -29°52', it is easiest to see from the southern hemisphere and cannot be seen from latitudes much north of 40°N. At magnitude 7.6, M83 is quite faint, and certainly not visible to the naked eye, but can be viewed through a pair of binoculars or a small telescope.

• April 17 – M3 well placed for observation. The globular cluster M3 (NGC 5272) in Canes Venatici will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +28°22', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 41°S. At magnitude 6.4, M3 is quite faint, and certainly not visible to the naked eye, but can be viewed through a pair of binoculars or a small telescope.

• April 18 – Conjunction between the Moon and Jupiter – 03:27 UTC. The Moon and Jupiter will make a close approach, passing within 2°06' of each other. At the moment of closest approach, the Moon will be at mag -12.4, and Jupiter at mag -2.4, both in the constellation 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.

• April 18 – Mercury at greatest elongation east – 11:34 UTC. Mercury will be well placed for observation in the evening sky, shining brightly at mag -2.2. Over coming weeks, the distance between Mercury and the Sun will decrease each night, and it will gradually sink back into the Sun's glare.

• April 20 – C/2013 X1 (PANSTARRS) at perihelion. Comet C/2013 X1 (PANSTARRS) will make its closest approach to the Sun, at a distance of 1.31 AU.

• April 22 – Full Moon – 05:25 UTC. The Moon will reach full phase – making it visible for much of the night, lying almost directly opposite the Sun in the sky. Full Moons are traditionally given names according to the season in which they fall, and this will be the second full moon of spring 2016, traditionally called the Milk Moon. Over the nights following April 22, the Moon will rise around an hour later each day so as to become prominent later in the night. Within a few days, it will only be visible in the pre-dawn and early-morning sky. By the time it reaches last quarter, a week after full moon, it will rise at around midnight and set at around noon. At the moment when the Moon reaches full phase, it will lie at a declination of -09°03' in the constellation Virgo, and so will appear high in the sky at all but the most extreme latitudes. It will be visible at all latitudes between 70°N and 89°S. Its distance from the Earth will be 406 000 km. This full moon was known by early Native American tribes as the Full Pink Moon because it marked the appearance of the moss pink, or wild ground phlox, which is one of the first spring flowers. This moon has also been known as the Sprouting Grass Moon, the Growing Moon, and the Egg Moon. Many coastal tribes called it the Full Fish Moon because this was the time that the shad swam upstream to spawn.

• April 22 – M101 well placed for observation. The pinwheel galaxy (M101, NGC 5457) will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +54°21', it is easiest to see from the northern hemisphere and cannot be seen from latitudes much south of 15°S. At magnitude 7.7, M101 is quite faint, and certainly not visible to the naked eye, but can be viewed through a pair of binoculars or a small telescope.

• April 22, 23 – Lyrid meteor shower. The Lyrid meteor shower will reach its maximum rate of activity on April 22, 2016. Some shooting stars associated with the shower are expected to be visible each night from April 19 to 25. The maximum rate of meteors expected to be visible from a dark location is around 10 per hour (ZHR). The Moon will be 16 days old at the time of peak activity, and being so close to Full Moon, will severely limit the observations that will be possible. The best place to look to see as many meteors as possible is not at the radiant itself, but at any dark patch of sky which is around 90° away from it, since it is at a distance of around 90° from the radiant that meteors will typically appear at their brightest.

• April 25 – Conjunction between the Moon and Mars – 05:33 UTC. The Moon and Mars will make a close approach, passing within 4°52' of each other. At the moment of closest approach, the Moon will be at mag -12.4, and Mars at mag -1.5, both in the constellation Ophiuchus. 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.

• April 25 – Conjunction between the Moon and Saturn – 19:44 UTC. The Moon and Saturn will make a close approach, passing within 3°18' of each other. At the moment of closest approach, the Moon will be at mag -12.4, and Saturn at mag 0.9, both in the constellation Ophiuchus. 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.

Video courtesy Hubble Space Telescope

Video courtesy NASA

Sources: InTheSky (Dominic Ford), SeaSky

Featured image background credit: Solar System Scope. Edit: TW