What’s Up – February 2017

Events of interest for February ….

FEBRUARY – Aurora season is in full swing – from now till around the end of March is the best time for viewing the northern lights here from the UK. Please visit our sister site AUK – Aurora UK for “real time” notifications. Also look out for Nacreous clouds – the high “oil puddle” in the sky  😉

1st February – MOON/MARS – The Moon and Mars will make a close approach, passing within 2°12′ of each other. The Moon will be 4 days old. From Scarborough, the pair will become visible at around 17:01 (GMT) as the dusk sky fades, 32° above your south-western horizon. They will then sink towards the horizon, setting 4 hours and 56 minutes after the Sun at 21:31. The Moon will be at mag -10.9, and Mars at mag 0.7, both in the constellation Pisces. 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.

4th February – MOON – 1st quarter moon –  The Moon will be prominent in the evening sky, setting around midnight. From Scarborough, it will become visible at around 17:08 (GMT) as the dusk sky fades, 46° above your southern horizon. It will then reach its highest point in the sky at 17:58, 47° above your southern horizon. It will continue to be observable until around 00:12, when it sinks to 8° above your western horizon. At this time in its monthly cycle of phases, it appears almost exactly half illuminated.

6th February – MOON – The Moon will reach the closest point along its orbit to the Earth and will appear slightly larger than at other times. The Moon’s distance from the Earth varies because its orbit is not perfectly circular – it is instead slightly oval-shaped, tracing out a path called an ellipse. As the Moon traverses this elliptical path around the Earth each month, its distance varies by around 10%, between 363,000 km and 405,000 km. Its angular size also varies by the same factor, and its brightness also changes, though this is hard to detect in practice, given the Moon’s phases are changing at the same time. The exact period of the Moon’s cycle between perigee (closest approach), apogee (furthest recess) and back again is 27.555 days – a period of time called an anomalistic month. This is very close to the Moon’s orbital period (27.322 days), but slightly longer. As the perigee of 6 February 2017 will occur when the moon is around first quarter phase, it will appear in the evening sky. On this occasion the Moon will pass within a distance of 368,000 km of the Earth, and appear with an angular diameter of 32.38 arcsec. This may be compared to its average size of 31.07 arcmin.

9th February – COMET – Comet 45P/Honda-Mrkos-Pajdusakova is forecast to reach its brightest, at around mag 6.6. It will lie at a distance of 0.95 AU from the Sun, and at a distance of 0.09 AU from the Earth. From Scarborough, it will be visible in the dawn sky, rising at 01:01 (GMT) – 6 hours and 33 minutes before the Sun – and reach an altitude of 40° above the south-eastern horizon before fading from view as dawn breaks at around 06:05. This event was automatically generated on the basis of orbital elements published by the Minor Planet Center (MPC), and is updated daily (last update, 30 Jan 2017). Note that the future positions of comets are typically known with a high degree of confidence, but their brightnesses are often much more unpredictable, since it is impossible to predict with certainty how they will respond as they move closer to the Sun. Magnitude estimates should be assumed to be highly provisional more than a few weeks in advance.

9th February – MOON/JUPITER – The Moon and Jupiter will make a close approach, passing within 2°33′ of each other. The Moon will be 18 days old. From Scarborough, the pair will be visible in the morning sky, becoming accessible at around 23:22, when they rise 7° above your south-eastern horizon. They will then reach its highest point in the sky at 03:46, 28° above your southern horizon. They will be lost to dawn twilight at around 06:58, 16° above your south-western horizon. The Moon will be at mag -12.3, and Jupiter at mag -2.3, both in the constellation Virgo. 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.

11th February – FULL MOON – The Moon will reach full phase. At this time in its monthly cycle of phases, the Moon lies almost directly opposite the Sun in the sky, placing it high above the horizon for much of the night. The sequence of full moons through the year are often assigned names according to the seasons in which they fall. This month’s will be the second to fall in winter 2017 – the Wolf Moon.Over the nights following 11 February, the Moon will rise around an hour later each day, becoming 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 exact moment when the Moon reaches full phase, it will lie at a declination of +13°09′ in the constellation Leo , and so will appear highest in the northern hemisphere. It will be visible from all latitudes south of 66°S. Its distance from the Earth will be 377,000 km.

11th February – MOON – There will be a penumbral eclipse of the Moon, visible from Scarborough in the southern sky. The Moon will lie 48° above the horizon at the moment of greatest eclipse. The eclipse will last from 22:35 until 02:54, and maximum eclipse will occur at 00:45 (all times given in Scarborough time). Like other lunar eclipses, penumbral eclipses occur whenever the Earth passes between the Moon and Sun, such that it obscures the Sun’s light and casts a shadow onto the Moon’s surface. But unlike other kinds of eclipses, they are extremely subtle events to observe. In a penumbral eclipse the Moon passes through an outer region of the Earth’s shadow called the penumbra. This is the outer part of the Earth’s shadow, in which the Earth appears to cover part of the Sun’s disk, but not all of it (see diagram below). As a result, the Moon’s brightness will begin to dim, as it is less strongly illuminated by the Sun, but the whole of the Sun’s disk will remain illuminated to some degree. Although the Moon’s light dims considerably during a penumbral eclipse, this is only perceptible to those with very astute vision, or in carefully controlled photographs. This is a rare occasion when the whole of the Moon’s face will pass within the Earth’s penumbra, and so the reduction of the Moon’s brightness will be more perceptible than usual. Such events are called total penumbral lunar eclipses, and are rare because the statistical chance that the Moon will enter the Earth’s umbra at some point is very high once it has passed fully within its penumbra, and this makes an eclipse a partial lunar eclipse.

15th February – MOON/JUPITER – The Moon and Jupiter will make a close approach, passing within 2°33′ of each other. The Moon will be 18 days old. From Scarborough, the pair will be visible in the morning sky, becoming accessible at around 23:22, when they rise 7° above your south-eastern horizon. They will then reach its highest point in the sky at 03:46, 28° above your southern horizon. They will be lost to dawn twilight at around 06:58, 16° above your south-western horizon. The Moon will be at mag -12.3, and Jupiter at mag -2.3, both in the constellation Virgo. 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.

17th February – VENUS – Venus will be well placed for observation in the evening sky, shining brightly at mag -5.5. From Scarborough , it will become visible at around 17:34 (GMT) as the dusk sky fades, 31° above your south-western horizon. It will then sink towards the horizon, setting 4 hours and 13 minutes after the Sun at 21:22. 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 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.

18th February – BODES GALAXY – Bode’s galaxy (M81, NGC 3031) in Ursa Major will be well placed for observation. It will reach its highest point in the sky at around midnight local time. At a declination of +69°04′, it is easiest to see from the northern hemisphere but cannot be seen from latitudes much south of 0°S. From Scarborough, it will be very well placed – it will be close enough to the north celestial pole that it will be high above the horizon all night. At magnitude 6.9, M81 is quite faint, and certainly not visible to the naked eye, but can be viewed through a pair of binoculars or small telescope.

18th February – MOON – Moon is at last quarter – The Moon will be prominent in the dawn sky, rising at around midnight. From Scarborough, it will be visible in the morning sky, becoming accessible at around 02:37, when it rises 7° above your south-eastern horizon. It will then reach its highest point in the sky at 06:04, 20° above your southern horizon. It will be lost to dawn twilight at around 06:52, 20° above your southern horizon. Over coming days, the Moon will rise later each day, so that it is visible for less time before sunrise and it less far above the eastern horizon before dawn. 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.

20th February – MOON/SATURN – The Moon and Saturn will make a close approach, passing within 3°34′ of each other. The Moon will be 23 days old. From Scarborough, the pair will be difficult to observe as they will appear no higher than 12° above the horizon. They will be visible in the dawn sky, rising at 03:54 (GMT) – 3 hours and 18 minutes before the Sun – and reach an altitude of 12° above the southern horizon before fading from view as dawn breaks at around 06:48. The Moon will be at mag -11.3 in the constellation Sagittarius, and Saturn at mag 0.2 in the neighbouring constellation of 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.

22nd February – MOON/PLUTO – The Moon and 134340 Pluto will share the same right ascension, with the Moon passing 2°47′ to the north of 134340 Pluto. The Moon will be 25 days old. From Scarborough, the pair will be difficult to observe as they will appear no higher than 8° above the horizon. They will be visible in the dawn sky, rising at 05:16 (GMT) – 1 hour and 52 minutes before the Sun – and reach an altitude of 8° above the south-eastern horizon before fading from view as dawn breaks at around 06:43. The Moon will be at mag -10.6, and 134340 Pluto at mag 14.9, both in the constellation Sagittarius. The pair will be too widely separated to fit within the field of view of a telescope, but will be visible through a pair of binoculars.

26th February – NEW MOON – Now is the time to be looking at all the Deep Sky Objects with no moon to interfere

27th February – MARS/URANUS – Mars and Uranus will share the same right ascension, with Mars passing 0°37′ to the north of Uranus. At around the same time, the two objects will also make a close approach, technically called an appulse. From Scarborough, the pair will become visible at around 18:21 (GMT) as the dusk sky fades, 27° above your south-western horizon. They will then sink towards the horizon, setting 4 hours and 12 minutes after the Sun at 21:41. Mars will be at mag 1.0, and Uranus at mag 5.9, both in the constellation Pisces. The pair will be a little too widely separated to fit comfortably within the field of view of a telescope, but will be visible through a pair of binoculars.

28th February – MOON/VENUS – The Moon and Venus will share the same right ascension, with the Moon passing 10°15′ to the south of Venus. The Moon will be 2 days old. From Scarborough, the pair will become visible at around 17:58 (GMT) as the dusk sky fades, 26° above your western horizon. They will then sink towards the horizon, setting 3 hours and 35 minutes after the Sun at 21:09. The Moon will be at mag -9.7 in the constellation Cetus, and Venus at mag -5.4 in the neighbouring constellation of Pisces. The pair will be too widely separated to fit within the field of view of a telescope or pair of binoculars, but will be visible to the naked eye.

Dates highlighted in BOLD are good photographic opportunities

AIUK – Astronomy Imaging UK – https://www.facebook.com/groups/453388178104679/

sister group to ……

AUK – Aurora UK – https://www.facebook.com/groups/AuroraUK/

Note: Times are UK (BST) unless noted differently.

Share

Leave a Reply

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.