February Skies 2023

I love February as it is the start of the Milky Way season when the Southern Cross rises earlier each night which also means that the Milky Way becomes more and more visible! So, start to check it out on the New Moon evening of the 20^th.

The Moon this Month

(All times are in Australian Eastern Daylight Time)

• Full Moon:                     February 6^th –  5:28am
• Third quarter Moon:     February 14^th –  3:00am
• New Moon                     February 20^th – 6:05pm
• First Quarter                  February 27^th – 7:05pm

The Micro Moon: A Phenomenon of Our Celestial Neighbour

Have you ever looked up at the moon and thought it looked smaller than usual? This might have been due to a micro moon! But what exactly is a micro moon and how does it happen? Let’s dive into the fascinating world of our celestial neighbour. This will be the case on February 6 at 5:28am.

The moon orbits the Earth in an elliptical path, not a perfect circle. This means that sometimes it is closer to us and sometimes it is further away. The point in the moon’s orbit where it is furthest from the Earth is called the apogee. When a full moon occurs at the same time as the moon’s apogee, it is referred to as a micro moon.

At this distance, the moon appears smaller in the sky compared to a typical full moon. This is because the apparent size of the moon is dependent on its distance from Earth. The moon is usually about 384,400 km away, but during a micro moon, it can be up to more than 406,000 km away. On February 5th the Moon will be at apogee at a distance of 406,465 km away. This might not seem like much, but it can result in a noticeable difference in the size of the moon in the sky.

However, it’s important to note that the micro moon still has the same impact on the tides and our daily lives. The moon’s gravitational pull is what causes the tides, and this is determined by the moon’s mass and distance from Earth, not its size in the sky.

The micro moon is just one of the many fascinating aspects of our celestial neighbour and its relationship with the Earth. It’s a reminder of the beauty and complexity of the universe around us and the many wonders that are yet to be discovered.

So the next time you look up at the moon and think it looks smaller than usual, remember the micro moon and all the amazing things we have yet to learn about our celestial neighbour.

February 20^th will see the second and last Super New Moon of 2023. The Super New Moon, like any other New Moon, won’t be visible from Earth, but the dark night skies will provide great opportunities for some night sky watching. On this night the Moon will be at perigee – its closest point in the orbit to us at 358,371 km from Earth.

February Skies

This month we will consider the constellation of Gemini the Twins. This is another of the traditional 48 constellations derived from Greek mythology like Orion. However, because it is also on the ecliptic, it is also a sign of the Zodiac. The ecliptic is the apparent path that the Sun, Moon and planets seem to follow across the sky throughout the year. Did you know that of the three none naked-eye planets (Uranus, Neptune and Pluto), two were discovered while they were in Gemini?. In 1781, William Herschel discovered Uranus, the first planet to be found using a telescope while it was in Gemini. Then in 1930,  Clyde Tombaugh found Pluto (now a dwarf planet) photographically while it was also in the constellation of the twins.

The mythical twins of Gemini were called Castor and Pollux, which are the names given to the brightest stars in the constellation. They also mark the position of the heads of each twin.

Many Australian Indigenous groups also view these stars as brothers. In the Wergaia traditions of western Victoria, they are the brothers Yuree and Wanjel. Yurree and Wanjel. Yurree is the fan-tailed cuckoo, and Wanjel is the long-necked tortoise. These hunters pursue and kill the kangaroo Purra. In eastern Tasmania, the constellation Gemini represents two ancestor men who created fire, walking on the road of the Milky Way – similar in orientation to the Greek constellation.

Planets in February

Mercury begins its journey back towards the Sun in the morning dawn this dawn this month, moving from Sagittarius into Capricornus. On the 19^th, the 28-day old Moon will be less than 4° from the planet. At this time, the Moon is a very slender crescent (just 4% illuminated by the Sun), and binoculars may assist in the brightening dawn. A good photo opportunity but be careful of the Sun rising.

Venus is easily visible early in the western evening sky. At the beginning of the month it is the constellation of Aquarius before it moves into Pisces on 16^th. Neptune, the outermost planet, has a close rendezvous with Venus on the 15^th, with the pair just 10 arcminutes apart. Unfortunately this conjunction will be almost impossible to observe, as the evening twilight sky is very bright. On the 22^nd, Venus will be just 1° from the limb of the waxing crescent of the 2-day old Moon. Lastly, Venus and Jupiter have been nearing each other during February and appear just 2° apart on the 28^th, and even closer in early March.

Since its opposition late last year, Mars has gradually faded, although still the brightest object in Taurus in the early northern evening sky. On the 28^th, the 8-day old waxing gibbous Moon appears 3° from the planet as seen in Figure 5.

Jupiter spends the first few days of the month in Pisces before moving into Cetus, then back into Pisces during the last week of February. Unfortunately, the planet’s low altitude in the early western evening sky does not lend itself to telescopic scrutiny or imaging. However, Jupiter, Venus, and the crescent Moon make a pleasant twilight vista for the unaided eye on the 22^nd and 23^rd . Venus rises toward Jupiter throughout February for a close rendezvous at month’s end.

Saturn will be in conjunction with the Sun on the 17^th and remains hidden from view until its return to the morning skies in mid-March.

Uranus, in Aries, appears low in the early north-western evening sky after the end of astronomical twilight. The planet remains in the constellation of the Ram until it moves into Taurus the Bull in 2024.

Neptune, in Aquarius, opens the month very low to the western horizon after dusk. On the 15^th, Venus will be a close 10 arcminutes from the outermost planet; this will be a most challenging observation.

Comets

Perhaps the first chance for observers around Sydney’s latitude to catch the most publicised Comet C/2022 E2(ZTF) will be on the evening of Sunday 5 February. Comet ZTF could be around 5^th magnitude and 6^o above the northwest horizon in the constellation of Auriga as evening twilight ends, a few degrees north of the star Capella. There will be a few challenges for observers. Firstly, the comet’s low altitude above the horizon will lead to atmospheric extinction – the comet will appear fainter than the actual magnitude. Secondly, because of the comet’s close distance to Earth (0.3 au), it will appear more diffuse as it is spread out over a wider area. Finally, the Moon will be just one day away from Full, though at least it will be low in the eastern sky. Also picking it out as green will be almost impossible due to these other issues.

Date	R.A.	Dec.	Delta (au)	R (au)	Elong. (o)	Mag.
4 Feb	5h 29.2m	+57o 48’	0.294	1.169	122	4.9
11 Feb	4h 48.2m	+26o 11’	0.419	1.209	112	5.7
18 Feb	4h 39.8m	+11o 28’	0.609	1.256	101	6.7

Having passed perihelion earlier in January it will fade as it moves away from the Sun and Earth. However, the behaviour and brightness of comets, especially post perihelion (after its closest passage to the Sun), can be unpredictable at times and well worth watching. Watch its close visit to Mars on 11th.

For those who don’t already look upon the night sky as an old friend, take the time now to become familiar with the evening northern sky.

If you want to test whether your horizon is low enough to spot the comet as it makes its southerly entrance, become familiar with finding the bright star, Capella.

METEOR SHOWER

The alpha-Centaurids, one of the main southern summer showers are active from January 28 to February 21, with a maximum zenith hourly rate of six around the 8^th. The shower is known for its bright yellow and blue coloured fireballs that frequently reach negative magnitude. The alpha-Centaurids are also well known for their long -lasting trains that may vary from seconds to several minutes. Since the radiant is above the horizon all night from most southern locations and their activity is spread over such a broad period, observers are sure to catch the odd meteor at any time. However, the Full Moon on the 6^th will spoil this year’s peak.

Object of the Month – Pleiades 

At about 9 pm AEDT on mid-February evenings, the Pleiades open star cluster, also known as the Seven Sisters, is well above the horizon in the Northern sky. The rest of its home constellation Taurus, the Bull, sits to the East of the cluster.

Visually, the cluster is composed of medium-bright, hot blue stars named Asterope, Merope, Electra, Maia, Taygeta, Celaeno, and Alcyone. In Greek mythology, those characters were the daughters of Atlas and half-sisters of the Hyades. They are indeed related — recently born of the same primordial gas cloud. Only six sister stars are usually apparent; their parents, Atlas and Pleione, are huddled together at the east end of the grouping. Many more stars are visible through binoculars, and over a hundred stars may be seen through a telescope.

Many cultures, including the Australian Indigenous people, have stories and interpretations of this lovely star cluster. It was significant that the ‘Dance of the Pleiades’ was performed by Pitjantjatjara Aboriginal women from the Central Desert at the Opening Ceremony of the Sydney Olympics in September 2000. However, when you are out camping in the bush in Australia, you know that the Pleiades women have visited your camp when you wake up with a freezing nose and the canvas of your tent or swag covered in icy white crystals. The Pleiades women first appear in the southern hemisphere in the early morning and flamboyantly sweep across the sky, excreting frost.

In Japan, it is called Subaru and forms the logo of that particular car brand. Due to its similar shape, the Pleiades are sometimes confused with the Little Dipper. 

Binocular challenges for this month.

Grab your binoculars, and if you have a stargazing app on your phone, head outside try for these objects in the evening sky.

Now the Milky Way is rising, there are some great opportunities to check it out in the binoculars. You can easily see the Large and Small Magellanic Clouds if you have dark enough skies. These are the 2 satellite galaxies orbiting the Milky Way in the Southern Sky early in the night. They look like 2 faint clouds to the west and above the Southern Cross.

Look above the Southern Cross into the Milky Way and check out as many ‘fuzzy’ patches as you can – it is a minefield of clusters and interesting binocular objects!

Clear skies until next month! Stay up to date on my Facebook page.
Donna ‘the Astronomer’