Sky Watching for November 2018

November 4th will see the Taurid meteor shower reaching maximum rate of activity. The meteor activity is expected to be visible from 20th October until 30th November. They can be found in the region of Taurus (figure 1).

Assuming a good dark sky viewing conditions should result in approximately 10 meteors per hour. However, it is more likely that only 7 meteors per hour will be detected due to the radiant being high in the night sky.
The moon will be 27 days old during the time of maximum activity thereby minimising the possibility of interference. The parent body for the Taurid meteor shower is comet 2P/Encke (figure 2b).

2P/Encke will be visible between approximately 19:50 and 00:12. It will rise 21° above the South East horizon, it will reach its highest point at 21:59, 27° above Southern horizon. It will disappear from view at 00:12 when it dips to 22° above the South Western horizon. Comet Encke is a periodic comet that completes an orbit of the Sun (figure 2a) once every 3.3 years. It was first recorded by Pierre Méchain in 1786 but it was not recognised as a periodic comet until 1819 when its orbit was computed by Johann Franz Encke; like Halley's Comet, it is unusual in being named after the calculator of its orbit rather than its discoverer. Like most comets, it has a very low albedo, reflecting only 4.6% of the light it receives. The diameter of the nucleus of the Comet is 4.8 km.


Fig. 1: Area of the Taurids in Taurus.
From Pembrokeshire the shower will be observable approximately 45° above the South East horizon at midnight. The meteors will be travelling outward from this point (figure 1).

Fig. 2a: Path of comet 2P Encke.

Fig. 2b: Comet Encke, Credit NASA Spitzer Telescope.
On 11th November the Moon and Saturn will make a close approach passing within 1° 26´ of each other. The Moon will be 4 days old.
From Pembrokeshire the pair will be difficult to see as they will be no higher than 12° above the horizon.
Visible at 15:55 (GMT) as dusk sky fades, 12° above the Southern horizon. They will then be seen toward the horizon, setting 2 hrs 44 mins after the Sun at 18:15. They will both appear in the constellation Sagittarius (figure 3).

Fig. 3:
On Friday 16th November the Moon and Mars (in Aquarius) will make a close approach passing within 0.57° of each other. The Moon will be 9 days old. They will both be visible in the evening sky from approximately 15:50 (GMT) as the dusk sky fades, 20° above the South East horizon. They will be observable until approximately 21:40 sinking to 8° above South Western horizon. The best viewing will be through a pair of binoculars.
Also on 16th November asteroid 3 Juno (figure 4) will become visible in the constellation Eridanus (figure 5), well above the horizon for most of the night.   

Fig. 4: 3 Juno, Credit NASA


Fig. 5: Constellation Eridanus.
It does not matter what your position is on Earth 3 Juno will reach its highest point in the sky at approximately midnight.
From Pembrokeshire it will be visible from 21:15 until 03:40. It will rise 21° above South Eastern horizon and reach its highest point at 00:30, 34° above the Southern horizon. It will then sink to 22° above the South Western horizon.
Optimal positioning occurs when it makes its closest approach to the point in the sky directly opposite to the Sun – an event termed opposition. Since the Sun reaches its greatest distance below the horizon at midnight, the point opposite to it is highest in the sky at the same time. At about the same time 3 Juno passes opposition, it makes its closest approach to Earth – termed its perigee – making it appear at its brightest in the night sky. This happens because when 3 Juno lies opposite to the Sun in the night sky, the solar system is lined up so 3 Juno, Earth and Sun lie in a straight line with Earth in the middle, on the same side of the Sun as 3 Juno. On this occasion, 3 Juno will pass within 1.031 AU (Astronomical Units), (figure 6) of us, reaching a peak brightness. At its brightest, 3 Juno is a faint object beyond the reach of the naked eye or binoculars; a telescope of moderate aperture and a good star chart (figure 7) are needed.
Astronomical Unit is a unit of length which is approximately equal to the distance of the Earth from the Sun.

Fig. 6: Astronomical Unit, 1 AU = 93 000 000 miles or 150 000 000 km.

Fig. 7: Path of Asteroid 3 Juno.

On 17th November M45 the Pleiades open star cluster will be in view from the constellation Taurus (figure 8).

Fig. 8: M45 in Constellation Taurus, 444 light years distant from Earth.
M45 (also known as the Seven Sisters and Messier 45) will be visible in the morning sky becoming accessible from 17:40 when it rises 12° above the North Eastern horizon. It will then reach its highest point in the sky at 00:20, 62° above the Southern horizon. It will disappear in the dawn twilight at 06:40, 15° above Western horizon. M45 will be visible to the unaided eye however a better view would be obtained using binoculars or a telescope.

Fig. 9: The Pleiades, Credit NASA/ESA
The Moon and M44 (figure 10) will make a close approach on November 27th passing within 0° 25´ of each other. The Moon will be 20 days old at the time. They will be visible in the morning sky becoming accessible at approximately 21:40, when they rise 7° above North East horizon. They will reach highest point in the sky at approximately 04:32, 57° above the Sothern horizon. Losing them to dawn twilight at 07:30, 42° above South Western horizon. They will both be in the constellation Cancer (figure 11). They will be observable using a pair of binoculars or a telescope.

Fig. 10: M44, the Beehive cluster, 177 light years distant, Credit NASA 

Fig. 11: Constellation Cancer.
The constellation Cancer is best known for its deep sky objects, and in particular the open cluster M44, the Beehive cluster or Praesepe. This can be found near the centre of the constellation.
The 30th November will see the Moon (figure 12) prominent in the dawn sky, rising at approximately midnight and will be in the last quarter.  

Fig: 12, Moon in last quarter in constellation Leo (figure 13).
It will become visible at 00:15 when it rises above the Eastern horizon. It will reach the highest point in the sky at 06:20, 50° above the Southern horizon. It will fade to dawn twilight at 07:30, 47° above the South Western horizon. Over the coming days it will then rise later each day so it will be visible for less time each day before sunrise. By the time it reaches new moon, it will rise at around dawn and set at around dusk, making it visible only during the daytime. This will be visible to the unaided eye. As with all observations using binoculars or telescopes will enhance viewing.

Fig. 13, Constellation Leo where Moon will be in its last quarter.

Fig. 14: Venus, Credit NASA.
Also on 30th November Venus will be well placed for observation in the dawn sky, shining brightly.
From Pembrokeshire it will rise at 03:13 (GMT) and reach an altitude of 23° above the south-eastern horizon before fading from view as dawn breaks at around 07:30.
Venus's orbit lies closer to the Sun than the Earth's, meaning that it always appears close to the Sun and is very difficult to observe most of the time.
It is observable only for a few weeks each time it reaches greatest separation from the Sun – moments referred to as greatest elongation.
On these occasions, however, Venus is so bright and conspicuous that it becomes the third brightest object in the sky after the Sun and Moon. It is often called the morning or evening star.
Venus’s brightness:
This depends on two factors: its closeness to the Earth, and its phase. Its phase varies depending on its position relative to the Earth. When it passes between the Earth and Sun, for example, the side that is turned towards the Earth is entirely unilluminated, like a new moon.
Conversely, when it lies opposite to the Earth in its orbit, passing almost behind the Sun, it appears fully illuminated, like a full moon. However, at this time it is also at its most distant from the Earth, so it is actually fainter than at other times.
Venus reaches its brightest when it is still a crescent – with less than half of its disk illuminated. This is because it is much closer to the Earth during its crescent phases than at other times.
As a result, during evening apparitions, Venus reaches maximum brightness a few days after it is at greatest separation from the Sun, which always coincides with it showing half-phase (dichotomy).
Conversely, during morning apparitions, Venus reaches maximum brightness a few days before it is at greatest separation from the Sun.

WARNING: Never attempt to view through binoculars, telescope or any optical aid an object close to the Sun. Also, never attempt to view the Sun unaided, doing so may result in immediate and permanent blindness. Always use astronomical approved viewing equipment.

The Stellarium software will assist greatly in locating objects in the sky, it is a useful astronomical tool.

Mark R Smith FRAS

Physicist
Nuclear Fusion & Astrophysics