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« January 2016


The Night Sky February 2016

Compiled by Ian Morison


This page, updated monthly, will let you know some of the things that you can look out for in the night sky.  It lists the phases of the Moon, where you will see the naked-eye planets and describes some of the prominent constellations in the night sky during the month.



Cambridge University Press has recently published two books by the author. An Amateurs Guide to Observing and Imaging the Heavens is a handbook aimed to bridge the gap between the beginner's books on amateur astronomy and the books which cover a single topic in great detail.   Stephen James O'Meara and Damian Peach have both given it excellent reviews. 'A Journey through the Universe' covering our current understanding of the Universe (up to June this year) was published on the 25th of September.   Martin Rees has written a very nice review of it.


Image of the Month

ngc1300

Hubble Image of NGC 1300

This view of the barred spiral galaxy NGC 1300 is one of the largest composite images that has ever been made by the Hubble Telescope.   The full size image can be accessed from the NASA APOD website searching for NGC 1300.   It lies some 70 million light years away in the constellation Eridanus and spans over 100,000 light years across.   (As does our Milky Way Galaxy.)   The heart of the galaxy shows a remarkable region of spiral structure and is thought to harbour a supermassive black hole.


Highlights of the Month

February - a great month to view Jupiter.

Jupiter
Jupiter imaged by Damian Peach

This is a great month to observe Jupiter.   It now lies low down in Leo and so is still reasonably high in the ecliptic and hence, when due south, at an elevation of ~45 degrees.

  The features seen in the Jovian atmosphere have been changing quite significantly over the last few years - for a while the South Equatorial Belt vanished completely (as seen in Damian's image) but has now returned to its normal wide state.   The diagram on right shows the main Jovian features as imaged by the author at the beginning of December 2012.

The image by Damian Peach was taken with a 14 inch telescope in Barbados where the seeing can be particularly good.   This image won the "Astronomy Photographer of the Year" competition in 2011.

See more of Damian Peach's images: Damian Peaches Website"





Jovian Features
Features in Jupiter's atmosphere - December 2013.





February: Look for the Great Red Spot on Jupiter

Great Red Spot
Observe the Great Red Spot
Image: NASA

This list gives some of the best evening times during February to observe the Great Red Spot which should then lie on the central meridian of the planet.

2nd   20:11         16th 21:40

4th   21.48         18th 23:18

6th   23:36         21st 20:47

7th   19:18         23rd 22:25

9th   20:56         28th 21:32

11th 22:33        

14th 20:02


1st February: before dawn: Mars and the third quarter Moon

Mars
Mars below the third quarter Moon
Image: Stellarium/IM

Before dawn on the first of the month, Mars and the third quarter Moon will be seen, if clear, due south.   As it nears the Earth, some details on the surface may now be seen if the seeing is good.   Antares, in Scorpius, may also be spotted low above the horizon.


February 6th: just before dawn: A very thin crescent Moon above Venus and Mercury

Moon
Venus and Mercury below a thin crescent Moon
Image: Stellarium/IM

Just before dawn and, given clear skies and a very low horizon towards the south-east, you may be able to spot a very thin crescent Moon hanging above both Venus, below, and Mercury down to its lower left.   Binoculars may well be needed to spot Mercury, but please do not use them after the Sun has risen.


February 13th: Observe the Moon occult a star

Moon
The Moon occults the star xi 1 Ceti.
Image: Stellarium/IM

If clear, around 19:20 on the evening of the 13th, the Moon will be seen to occult the 4.4th magnitude star xi 1 Ceti.   The chart show the position of the star as seen from Manchester just before it is occulted by the un-illuminated disk of the Moon.   It will reappear below the Moon's illuminated disk at around 20:19.   The timings will vary somewhat across the UK.


February 14th: The Moon passes close to the Hyades Cluster

The Moon
The Moon passes through the Hyades Cluster.
Image: Stellarium/IM

A very nice visual or photo opportunity when the first quarter Moon passes close to the V-shaped Hyades Cluster.   The red giant star, Aldebaran, shining at magnitude +0.8 is not part of the cluster but lies part way towards it.


February 23rd: The Moon close to Jupiter

Jupiter
The Moon passes close to Jupiter.
Image: Stellarium/IM

On the night of the 23rd/24th of February, the near full Moon, will pass below Jupiter.   The diagram shows the relative positions at ~21:30 in the evening and also the positions of the Gallilean satellites.


February 15th and 28th evening: The Hyginus Rille

20thJuly
Hyginus Rille location: IM.

For some time a debate raged as to whether the craters on the Moon were caused by impacts or volcanic activity.   We now know that virtually all were caused by impact, but it is thought that the Hyginus crater that lies at the centre of the Hyginus Rille may well be volcanic in origin.   It is an 11 km wide rimless pit - in contast to impact craters which have raised rims - and its close association with the rille of the same name associates it with internal lunar events.   It can quite easily be seen to be surrounded by dark material.   It is thought that an explosive release of dust and gas created a vacant space below so that the overlying surface collapsed into it so forming the crater.

Hyginus Rille
Hyginus Crater and Rille

M109 imaged with the Faulkes Telescope

M109
Messier 109
Image: Daniel Duggan
Faulkes Telescope North.

The Galaxy M109, imaged by Daniel Duggan.
This image was taken using the Faulkes Telescope North by Daniel Duggan - for some time a member of the Faulkes telescope team.   It shows the barred spiral galaxy M109 that lies at a distance of 83 million light years in the constellation of Ursa Major.   It is the brightest galaxy in the Ursa Major group of some 50 galaxies.   Our own Milky Way galaxy is now thought to be a barred spiral like M109.

Learn more about the Faulkes Telescopes and how schools can use them: Faulkes Telescope"











Observe the International Space Station

The International Space Station
The International Space Station and Jules Verne passing behind the Lovell Telescope on April 1st 2008.
Image by Andrew Greenwood

Use the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK. (Across the world too for foreign visitors to this web page.)

Note: I observed the ISS three times recently and was amazed as to how bright it has become.

Find details of sighting possibilities from your location from: Location Index

See where the space station is now: Current Position


The Moon

3rd Quarter Moon
The Moon at 3rd Quarter. Image, by Ian Morison, taken with a 150mm Maksutov-Newtonian and Canon G7.
Just below the crator Plato seen near the top of the image is the mountain "Mons Piton".   It casts a long shadow across the maria from which one can calculate its height - about 6800ft or 2250m.
`
new moon first quarter full moon last quarter
February 8th February 15th February 22nd February 1st

Some Lunar Images by Ian Morison, Jodrell Bank Observatory: Lunar Images

A World Record Lunar Image

World record Lunar Image
The 9 day old Moon.

To mark International Year of Astronomy, a team of British astronomers have made the largest lunar image in history and gained a place in the Guinness Book of Records! The whole image comprises 87.4 megapixels with a Moon diameter of 9550 pixels. This allows details as small as 1km across to be discerned! The superb quality of the image is shown by the detail below of Plato and the Alpine Valley. Craterlets are seen on the floor of Plato and the rille along the centre of the Alpine valley is clearly visible. The image quality is staggering! The team of Damian Peach, Pete lawrence, Dave Tyler, Bruce Kingsley, Nick Smith, Nick Howes, Trevor Little, David Mason, Mark and Lee Irvine with technical support from Ninian Boyle captured the video sequences from which 288 individual mozaic panes were produced. These were then stitched together to form the lunar image.

Plato and the Alpine valley
Plato and the Alpine Valley.

Please follow the link to the Lunar World Record website and it would be really great if you could donate to Sir Patrick Moore's chosen charity to either download a full resolution image or purchase a print.



The Planets

 A montage of the Solar System
A montage of the Solar System. JPL / Nasa

Jupiter

Jupiter
A Cassini image of Jupiter . Nasa

Jupiter will reach opposition on the 8th of next month and so this is one of three superb months during which to observe it - visible from late evening to dawn.   Jupiter starts the month in the extreme south of Leo close to the boarder of Virgo and, during the month moves slowly northwards and westwards in retrograde motion across the heavens.   The size of Jupiter's disk increases slightly from 42 to 44 arc seconds as February progresses with its magnitude increasing very slightly from -2.4 to -2.5.   With a small telescope one should be easily able to see the equatorial bands in the atmosphere, sometimes the Great Red Spot and up to four of the Gallilean moons as they weave their way around it.


See highlight above.


Saturn

Saturn
The planet Saturn. Cassini - Nasa

Saturn is now a morning object, rising at ~04:30 UT as the month begin but by about 03:00 UT at its end.   It lies in Ophiuchus near the 'fan' of Scorpius and 7.5 degrees above Antares.   Its diameter increases from 15.8 to 16.5 arc seconds during the month as it shines at magnitude +0.5.   It will be high enough in the south-east before dawn to make out the beautiful ring system which has now opened out to ~26 degrees - virtually as open as they ever become.   It will best observed just before dawn but if only it were higher in the ecliptic; its elevation never gets above ~20 degrees and so the atmosphere will hinder our view of this most beautiful planet.



Mercury

Mercury.
Messenger image of Mercury Nasa

Mercury, shining at magnitude zero, lies fairly near Venus during February and reaches greatest elongation from the Sun on the 7th.   It should be visible low in the East for the first half of the month.   It lies closest to Venus on the 13th when it is 4 degrees down to its lower left.   A low eastern horizon will be needed to spot them as the pair will be less than 10 degrees high some 30 minutes before sunrise.



See highlight above.





Mars

Mars showing Syrtis major.
A Hubble Space Telescope image of Mars.
Jim Bell et al. AURA / STScI / Nasa

Mars , lies in Libra during the month moving eastwards relative to the stars.   Its brightness increases slightly from magnitude +0.8to +0.3 as the angular size of its disk grows from 6.8 down to 8.6 arc seconds towards the end of February.   It is highest in the morning twilight and then, given a good telescope and excellent 'seeing', it might be possible to spot the north polar cap and possibly Syrtis Major.   Mars is moving towards opposition on May 22nd and its closest approach to Earth on the 30th when it will have an angular diameter of 18.6 arc seconds and shine almost as brightly as Jupiter.



See highlight above.







Venus

Venus
Venus showing some cloud structure

Venus, is nearing the end of a long morning apparition when it has dominated the eastern sky before dawn.   It rises at the start of the month as twilight begins but only an hour before sunrise by month's end.   As the angle of the ecliptic to the horizon is small at this time of the year, Venus is especially low above the horizon, but even so, shining at a magnitude of -3.9 it is still easily visible given a good eastern horizon.   During the month, its angular size drops from 12 to 11 arc seconds but, at the same time, the percentage of the illuminated disk increases from 85 to 90% which explains why the magnitude stays constant.   It stays close to Mercury and lies 4 degrees to its upper right on the 10th of the month.



See highlight above.



Radar Image of Venus
Radar image showing surface features



Find more planetary images and details about the Solar System: The Solar System



The Stars

The Mid Evening February Sky

FebruarySky
The February Sky in the south-east - mid evening.

This map shows the constellations seen in the south during the evening. The brilliant constellation of Orion is seen in the south. Moving up and to the right - following the line of the three stars of Orion's belt - brings one to Taurus; the head of the bull being outlined by the V-shaped cluster called the Hyades with its eye delineated by the orange red star Aldebaran. Further up to the right lies the Pleaides Cluster. Towards the zenith from Taurus lies the constellation Auriga, whose brightest star Capella will be nearly overhead. To the upper left of Orion lie the heavenly twins, or Gemini, their heads indicated by the two bright stars Castor and Pollux. Down to the lower left of Orion lies the brightest star in the northern sky, Sirius, in the consteallation Canis Major. Up and to the left of Sirius is Procyon in Canis Minor. Rising in the East is the constellation of Leo, the Lion, with the planet Saturn up and to the right of Regulus its brightest star. Continuing in this direction towards Gemini is the faint constellation of Cancer with its open cluster Praesepe (also called the Beehive Cluster),the 44th object in Messier's catalogue. On a dark night it is a nice object to observe with binoculars. There is also information about the constellation Ursa Major,seen in the north, in the constellation details below.

The constellation Taurus

Taurus
Taurus

Taurus is one of the most beautiful constellations and you can almost imagine the Bull charging down to the left towards Orion. His face is delineated by the "V" shaped cluster of stars called the Hyades, his eye is the red giant star Aldebaran and the tips of his horns are shown by the stars beta and zeta Tauri. Although alpha Tauri, Aldebaran, appears to lie amongst the stars of the Hyades cluster it is, in fact, less than half their distance lying 68 light years away from us. It is around 40 times the diameter of our Sun and 100 times as bright.

The Pleiades
AAO Image of the Pleiades, M45, by David Malin

To the upper right of Taurus lies the open cluster, M45, the Pleiades. Often called the Seven Sisters, it is one of the brightest and closest open clusters. The Pleiades cluster lies at a distance of 400 light years and contains over 3000 stars. The cluster, which is about 13 light years across, is moving towards the star Betelgeuse in Orion. Surrounding the brightest stars are seen blue reflection nebulae caused by reflected light from many small carbon grains. These relfection nebulae look blue as the dust grains scatter blue light more efficiently than red. The grains form part of a molecular cloud through which the cluster is currently passing. (Or, to be more precise, did 400 years ago!)

The Crab Nebula
VLT image of the Crab Nebula

Close to the tip of the left hand horn lies the Crab Nebula, also called M1 as it is the first entry of Charles Messier's catalogue of nebulous objects. Lying 6500 light years from the Sun, it is the remains of a giant star that was seen to explode as a supernova in the year 1056. It may just be glimpsed with binoculars on a very clear dark night and a telescope will show it as a misty blur of light.

The Crab Nebula
Lord Rosse's drawing of M1

Its name "The Crab Nebula" was given to it by the Third Earl of Rosse who observed it with the 72 inch reflector at Birr Castle in County Offaly in central Ireland. As shown in the drawing above, it appeared to him rather lile a spider crab. The 72 inch was the world's largest telelescope for many years. At the heart of the Crab Nebula is a neutron star, the result of the collapse of the original star's core. Although only around 20 km in diameter it weighs more than our Sun and is spinning 30 times a second. Its rotating magnetic field generate beams of light and radio waves which sweep across the sky. As a result, a radio telescope will pick up very regular pulses of radiation and the object is thus also known a Pulsar. Its pulses are monitored each day at Jodrell Bank with a 13m radio telescope.

The constellation Orion

Orion
Orion

Orion, perhaps the most beautiful of constellations, will be seen in the south at around 11 - 12 pm during January. Orion is the hunter holding up a club and shield against the charge of Taurus, the Bull up and to his right. Alpha Orionis, or Betelgeuse, is a read supergiant star varying in size between three and four hundred times that of our Sun. The result is that its brightness varies somewhat. Beta Orionis, or Rigel, is a blue supergiant which, at around 1000 light years distance is about twice as far away as Betelgeuse. It has a 7th magnitude companion. The three stars of Orion's belt lie at a distance of around 1500 light years. Just below the lower left hand star lies a strip of nebulosity against which can be seen a pillar of dust in the shape of the chess-board knight. It is thus called the Horsehead Nebula. It shows up very well photographically but is exceedingly difficult to see visually - even with relativly large telescope.

The Orion Nebula
The Horsehead Nebula: Anglo Australian Observatory

Beneath the central star of the belt lies Orion's sword containing one of the most beautiful sights in the heavens - The Orion Nebula. It is a region of star formation and the reddish colour seen in photographs comes from Hydrogen excited by ultraviolet emitted from the very hot young stars that make up the Trapesium which is at its heart. The nebula, cradling the trapesium stars, is a beautiful sight in binoculars or, better still, a telescope. To the eye it appears greenish, not red, as the eye is much more sensitive to the green light emitted by ionized oxygen than the reddish glow from the hydrogen atoms.

The Orion Nebula
The Orion Nebula: David Malin

The constellation Ursa Major

Ursa Major
Ursa Major

The stars of the Plough, shown linked by the thicker lines in the chart above, form one of the most recognised star patterns in the sky. Also called the Big Dipper, after the soup ladles used by farmer's wives in America to serve soup to the farm workers at lunchtime, it forms part of the Great Bear constellation - not quite so easy to make out! The stars Merak and Dubhe form the pointers which will lead you to the Pole Star, and hence find North. The stars Alcor and Mizar form a naked eye double which repays observation in a small telescope as Mizar is then shown to be an easily resolved double star. A fainter reddish star forms a triangle with Alcor and Mizar.

Ursa Major contains many interesting "deep sky" objects. The brightest, listed in Messier's Catalogue, are shown on the chart, but there are many fainter galaxies in the region too. In the upper right of the constellation are a pair of interacting galaxies M81 and M82 shown in the image below. M82 is undergoing a major burst of star formation and hence called a "starburst galaxy". They can be seen together using a low power eyepiece on a small telescope.

M81 and M82
M81 and M82

Another, and very beautiful, galaxy is M101 which looks rather like a pinwheel firework, hence its other name the Pinwheel Galaxy. It was discovered in1781 and was a late entry to Messier's calalogue of nebulous objects. It is a type Sc spiral galaxy seen face on which is at a distance of about 24 million light years. Type Sc galaxies have a relativly small nucleus and open spiral arms. With an overall diameter of 170,000 light it is one of the largest spirals known (the Milky Way has a diameter of ~ 130,000 light years).

M101
M101 - The Ursa Major Pinwheel Galaxy

Though just outside the constellation boundary, M51 lies close to Alkaid, the leftmost star of the Plough. Also called the Whirlpool Galaxy it is being deformed by the passage of the smaller galaxy on the left. This is now gravitationally captured by M51 and the two will eventually merge. M51 lies at a distance of about 37 million light years and was the first galaxy in which spiral arms were seen. It was discovered by Charles Messier in 1773 and the spiral structure was observed by Lord Rosse in 1845 using the 72" reflector at Birr Castle in Ireland - for many years the largest telescope in the world.

M51
M51 - The Whirlpool Galaxy

Lying close to Merak is the planetary nebula M97 which is usually called the Owl Nebula due to its resemblance to an owl's face with two large eyes. It was first called this by Lord Rosse who drew it in 1848 - as shown in the image below right. Planetary nebulae ar the remnants of stars similar in size to our Sun. When all possible nuclear fusion processes are complete, the central core collpses down into a "white dwarf" star and the the outer parts of the star are blown off to form the surrounding nebula.

Owl Nebula Owl Nebula
M97 - The Owl Planetary Nebula Lord Rosse's 1848 drawing of the Owl Nebula