Explore Astronomy

Astronomy Picture of the Day
« January 2022
March 2022 »


Monthly Night Sky Guide February 2022


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.


New(ish)

The author's: Astronomy Digest

which, over time, will provide useful and, I hope, interesting articles for all amateur astronomers.   A further aim is to update and add new material to link with the books recently published by Cambridge University Press and which are described on the home page of the digest.   It now includes over 100 illustrated articles.



Image of the Month

Orion


Image: Ian Morison.

The constellation Orion is high in the southern sky this month.   This image is a composite of an RGB image and an image taken in the light of the red emission of excited Hydrogen (the H-alpha line).   It shows the arc of Barnard's Loop over to the left and, less well known, the Angel Fish Nebula above.   In the sword of Orion lies the Orion Nebula, M42, and just below Alnitak, the lower left star of Orion's belt, is the Horsehead Nebula.   Over to the left of Betelgeuse in the constellation Monocerous can be seen the Rosette Nebula.   This is perhaps the most beautiful region of the Heavens and the H-alpha emission adds much to the image.

Highlights of the Month


February, evening: the Double Cluster and the 'Demon Star', Algol.

Algol
Algol and the Double Cluster.
Image: Stellarium/IM

This month is a good time to look high in the southwest towards the constellations of Cassiopea and Perseus.   Perseus contains two interesting objects; the Double Cluster between the two constellations and Algol the 'Demon Star'.   Algol in an eclipsing binary system as seen in the diagram below.   Normally the pair has a steady magnitude of 2.2 but every 2.86 days this briefly drops to magnitude 3.4.

Double Cluster
Double Cluster imaged by IM and the Algol Light Curve



February: find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum

M31
How to find M31
Image: Stellarium/IM

In the early evenings when the Moon is not prominent, the galaxy M31 in Andromeda will be visible high in the southwest. The chart provides two ways of finding it:

1) Find the square of Pegasus.  Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit.  Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction.  You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye.   The photons that are falling on your retina left Andromeda well over two million years ago!

2) You can also find M31 by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right as shown on the chart.   As Pegasus is low down in the sky, this is the best way this month.

Around new Moon (1st of February) - and away from towns and cities - you may also be able to spot M33, the third largest galaxy after M31 and our own galaxy in our Local Group of galaxies.   It is a face on spiral and its surface brightness is pretty low so a dark, transparent sky will be needed to spot it using binoculars (8x40 or, preferably, 10x50).   Follow the two stars back from M31 and continue in the same direction sweeping slowly as you go.   It looks like a piece of tissue paper stuck on the sky just a bit brighter than the sky background.   Good Hunting!



February 3rd - after sunset: Jupiter and a thin crescent Moon.

Moon
Three planets and a 2.2 day old crescent Moon.
Image: Stellarium/IM

If clear after sunset on the 3rd, Jupiter may be seen down to the right of a very thin crescent Moon.   Binoculars may well be needed to cut through the Sun's glare, but please do not use them until after the Sun has set.

February 5th before dawn: -

Planets
Venus, Mars and Mercury.
Image: Stellarium/IM

If clear before dawn on the 5th, one could spot Venus lying above Mars, down to its lower right, and Mercury, down to the lower left.   Binoculars may well be needed to cut through the Sun's glare, but please do not use them after the Sun has risen.

February 13th Febuary - evening: the Moon in Gemini

Moon
The Moon in Gemini.
Image: Stellarium/IM
If clear, and looking high in the southeast, the 12 day old Moon will be seen close to the star Pollux in Gemini.

February 26th - before dawn: Venus, Mars anda crescent Moon

Mars
Venus, Mars and the Moon
Image: Stellarium/IM
If clear, and given a low horizon towards the southeast, Venus should be very prominent with Mars lying below and a 24.7 day old Moon over to its lower right.

February 10th and 24th evening: The Hyginus Rille

20thJuly
Hyginus Rille location: IM.

During these evenings the terminator lies close so making it more obvious. 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"


















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 third quarter
February 1st February 8th February 16th February 23th

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 9,550 pixels.  The resolution of ~0.4 arc seconds 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 8 day old Moon

Lunar Image
The 8 day old Moon imaged by Ian Morison.

This image was taken by the author on a night in March 2018 when the Moon was at an elevation of ~52 degrees and the seeing was excellent.   This enabled the resolution of the image to be largely determined by the resolution of the 200 mm aperture telescope and the 3.75 micron pixel size of the Point Grey Chameleon 1.3 megapixel video camera.   The use of a near infrared filter allowed imaging to take place before it was dark and also reduced the effects of atmospheric turbulence.   The 'Drizzle' technique developed by the Hubble Space Telescope Institute (HSTI) was used to reduce the effective size of the camera's pixels to allow the image to be well sampled.   Around 100 gigabytes of data, acquired over a 2 hour period, was processed to produce images of 54 overlapping areas of the Moon which were then combined to give the full lunar disk in the free 'stitching' program Microsoft ICE.   A further HSTI development called 'deconvolution sharpening' was then applied to the image.   The Moon's disk is ~6,900 pixels in height and has a resolution of 0.6 to 0.7 arc seconds.   Interestingly, as seen in the inset image, the rille lying along the centre of the Alpine Valley is just discernable and this is only ~0.5 km wide!   [Due to size limitations the large image is 2/3 full size.]









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. As darkness falls at the start of January, Jupiter, having a magnitude of -2.05 and an angular size of 33.65 arc seconds, may be seen low in the southwest, setting at 19:08 GMT   It will be rapidy lost in the Sun's glare as the month progresses.   Sadly, its very low elevation will hinder our view of the solar system's giant planet.



Saturn

Saturn
The planet Saturn. Cassini - Nasa

Saturn passes behind the Sun on the 4th of February and so cannot be seen this month.




Mercury

Mercury.
Messenger image of Mercury Nasa


Mercury. At the start of the month, Mercury can be seen low in the southeast just before dawn.   It will then have a magnitude of ~0.54 and an angular size of ~9 arc seconds.   As the day's progress it rises higher in the sky reaching maximum elongation (west) of the Sun on the 14th when it will achieve magnitude zero.   It will then soon be lost in the Sun's glare.   Binoculars may well be needed to spot it, but please do not use them after the Sun has risen.





Mars

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

This month, Mars can be seen in the south-eastern pre-dawn sky having a magnitude of +1.4 on the first with an angular size of 4.33 arc seconds.   As the month progresses, with the Sun rising earlier, it stays at a similar elevation before dawn.   Binoculars may well be needed to spot it, but please do not use them after the Sun has risen.




Venus

Venus
Venus showing some cloud structure

Venus now dominates the pre-dawn sky in the southeast, starting the month with a magnitude of -4.82 and having an angular size of 49 arc seconds showing a thin crescent disk.   As the month progresses, its phase increases but its angular size reduces so its magnitude hardly changes.





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