The Night Sky This Month: January 2019

Lunar Eclipse 2019-01-21
Image Credit: NASA

The map above shows the areas of the Earth’s surface from which a total eclipse of the Moon by Earth’s umbra, or dark shadow, on the night of the 21st of January can be observed. Although observers located in the unshaded areas on this map will be able to experience the 5-hour long event, the UK is located on the extreme western edge of the unshaded area.

As a result of the UK’s position, observers in the UK will only be able to see the start of the eclipse from about 02:30 (GMT) in the morning onwards. With some luck and depending on location though, most UK-based observers may see the Moon emerge completely from Earth’s shadow before dawn, which occurs at 07:37, with the Moon expected to emerge fully from the umbra at 07:48 GMT.    

The Moon Phases

Full Moon Last Quarter New Moon First Quarter
22nd December 29th December 6th January 14th January

The Planets in January 2019

– Mercury will not be observable for much of January, since it is now moving in behind the Sun. In practice, this means that the little planet will reach its highest elevation, which is only about 4 degrees or so, during daylight hours.

– Venus is now a brilliant pre-dawn object as it approaches its furthest point west from the Sun. Look for Venus about 22 degrees above the southern horizon from about four hours before dawn, which occurs at 07:37 GMT.

– Mars is presently a conspicuous early evening object. From the southern UK, it is visible from about 16:45 GMT at an elevation of 36 degrees above the southern horizon to about 22:05 or so. The latter, however, is at a much lower elevation of about 10 degrees or so above the western horizon.

– Jupiter has now emerged from behind the Sun, and with some luck, it might be visible as a pre-dawn object from about 2 hours or so before sunrise- albeit at a maximum elevation of only 9 degrees above the south-eastern horizon.

– Saturn is not well placed for observation at this time, as it is only about 4 degrees away from the Sun as it approaches a position of solar conjunction.

– Uranus is still visible as an evening object from about 17:24 GMT at an elevation of about 42 degrees above the south-eastern horizon. Although the planet will remain visible until about midnight or so, its elevation will reduce to about 21 degrees above the western horizon.

– Neptune is also still an early evening object, which becomes visible at about 17:25 GMT or so from the southern UK, from where it will rise to an elevation of about 30 degrees above the southern horizon. Note that even though Neptune will rise about 6 hours or so after the Sun, it sinks fairly rapidly, and may not be visible much beyond about 20:00 or so.

Meteor Showers in January 2019

The Quadrantid meteor shower is expected to peak on the night of 3rd/4th January, although increased meteor activity may occur for two or three days on either side of the expected peak date.

This year, the expected maximum hourly rate is about 80, but since this assumes a perfectly dark sky and an observing position directly under the radiant point, the actual number of meteors that are visible may be considerably less, depending on your observing position. Nonetheless, since the Moon will be 28 days old on the peak date, moon light will not intrude, and observers in the southern UK can expect to see about 40 or so meteors per hour. 

Deep Sky Objects to Look For In January 2019

January of 2019 may not offer much in the way of planetary observing, but it does compensate for this by offering excellent opportunities to view some spectacular star clusters, all of which are easy targets for binoculars and small telescopes. Below are some details-

M45 (Pleiades)

Pleiades Cluster

Also known as the Seven Sisters, this cluster contains about 1,000 stars, most of which are hot, blue stars that all formed from the same material about 100 million years ago. Note that the blue haze that surrounds most of the stars in the cluster is not caused by leftover material out of which the cluster had formed. Instead, the blue glow is caused by an unrelated carbon-rich dust cloud through which the cluster moved about 400 years ago.

Sadly, though, this strikingly beautiful cluster is expected to last for only another 250 million years or so, by which time gravitational influences from surrounding objects will cause the cluster to drift apart. In its current state the cluster’s core stretches over 8 light years, and the entire structure has a tidal radius of around 43 light years.

Messier 5

Although this cluster (located in Serpens) is not among the most massive of the Milky Ways’ globular clusters, it counts among the oldest, being about 13 billion years old. It is also among the largest globular clusters; its population of between 100,000 and 500,000 ancient stars stretches over about 165 light years, and exerts a cumulative gravitation influence over its neighborhood for more than 200 light years. 

M5 is located about 24,500 light years away from us, and with binoculars under dark skies it appears as a faint, but clearly non-stellar object close to the star 5 Serpentis, in the constellation Serpens. Note that medium to large telescopes are required to resolve the cluster into individual stars.

Messier 13 (Great Hercules Cluster)

The Great Hercules Cluster

This image shows a “close-up” view of the core of the Hercules Globular Cluster, which contains several hundred thousand stars in total, and which stretch over a distance of about 135 light years. The stars in this cluster are packed close together, so closely in fact that the average density of the stars in the cluster’s inner regions is about 100 times greater than the average stellar density in Sun’s immediate vicinity.

Interestingly, M13 was the target of an experimental message, known as the Arecibo Message, containing information about human DNA, Earth’s position, atomic numbers, and other details about the solar system that was sent from the Arecibo Radio Telescope in 1974. However, since the cluster is about 22,000 light years away, it is expected that the message will miss the cluster entirely, since it will no longer be in the position it was in 1974 when the message arrives in 22,000 years’ time.

Nonetheless, in its current position, M13 can be observed with binoculars and small to medium telescopes throughout the year from latitudes north of 36N, with the best views occurring during summer and spring.

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