CDAA

Written by David Pugh

I hope you are all keeping well. Next Thursday Feb 6th at 7.30pm will be CDAA's monthly meeting. I will be giving an illustrated talk "Shooting for the Stars" showing recent astro images taken and describing the objects captured. After tea/coffee and the raffle I will then give a Stellarium software presentation on the night sky this month which looks very interesting. Hope to see you there.

In the night sky this month there is a lot happening so lets hope for some clear nights!

Mercury, the inner-most planet, rises to 8 degrees above the western horizon after sunset in the last few days of the month, shining at mag -1. Binoculars are useful for this but make sure the Sun is below the horizon before searching. Dazzling Venus reaches it's brightest (mag -4.6) on Feb 14th and highest altitude of 35 degrees on Feb 7th in the SW at sunset. For telescope users, Venus will be in its crescent phase throughout the month and by the end of the month appears as a large thin crescent 49" in diameter. Venus lies 2 degrees N of the crescent Moon on Feb 1st.

Mars, the red planet, (mag +1.1), remains a splendid sight high in Gemini all month. A 100mm scope will give a good view of the planet. Red and orange filters can be helpful in spotting surface features. The wedge or V-shaped Syrtis Major becomes more favourably placed in the second half of the month. On Feb 9th at around 19.00UT Mars will lay only 5' S of the Moon's southern edge. Not to be missed if it is clear! Jupiter, king of the planets, (mag -2.5), shines like a beacon high in the evening sky in Taurus, above Aldebaran. Even a pair of binoculars shows its globe and its 4 galilean moons, often in a line. A telescope shows much more detail including its equatorial belts and the famous but shrinking Great Red Spot plus, occasionally, the transit of one of its moons across its surface. Well worth keeping an eye on, especially on Feb 25th when there is loads happening!. That evening the shadow of Ganymede transits Jupiter's disc at 18.35-21.12UT and the moon Europa keeps pace at the same time. Europa's shadow transits at 21.00-23.36UT, while Io undergoes an occultation disappeareance at 21.05UT! Also at 19.08UT on Feb 8th Callisto lies only 3" S of Jupiter's southern pole.

Saturn, the lovely ringed planet, (mag +1.1), still lies in Aquarius but is now sinking down in the SW in the post sunset twilight. The only chance of seeing it is at the start of the month as early as possible after sunset. The ice giant Uranus (mag +5.7) is still well placed in Aries. It can be observed with binoculars but you will need a telescope to resolve its small greenish disc. Neptune (mag +7.9) is an early evening object in Pisces but only observable immediatley after sunset in the SW in the first week of February.

On Feb 1st Venus, Saturn and Neptune are in the same evening twilight area of the sky, joined by a 12% lit waxing crescent Moon. On Feb 28th there's a chance to spot a thin (less than 1% lit) waxing crescent Moon which sets 50 minutes after the Sun.

Still nothing happening concerning the possible imminent outburst of the recurrent nova T Coronae Borealis currently at mag 10. If it does outburst in the next few weeks, it now rises before midnight in the NE. It last outburst in 1946 reaching mag 3.0 and mag 2.0 in 1866 when it was discovered. It is nicknamed the "Blaze Star"

All of the deep sky objects and constellations mentioned in the last two months are still well placed for observing, including Orion culminating at around 20.30UT at the start of the month. This month, I would like to look at Gemini the twins with its first magnitude stars Castor and Pollux. Mar is currently close to these stars, making for a lovely small triangle in the sky. Castor is a famous multiple star of 6 stars in 3 binary systems. Castor A and B are A type white stars about 4" apart, so fairly challenging to split. Castor C is a red dwarf star of mag 8.8 73" from A and B. Each of these 3 stars is a spectroscopic binary. In comparison Pollux is a single star but brighter (mag +1.14), and is a KO type orange giant star. The best deep sky object in Gemini is the bright, rich open star cluster M35. It lies near the foot of the left twin and spans 28' across and, at mag 5.1, can be easily viewed with binoculars. However, the view with a telescope is splendid showing 150 stars of mag 8 and fainter. As a real challenge there is also a far more distant open star cluster NGC 2158 just SW of M35 in the same field of view using a low power eyepiece. It will appear as a faint haze as the brightest stars are mag 13. This is because this cluster lies 13,000 lys away, six times further than M35! Finally, for imagers, the Jellyfish Nebula IC 443 is a challenging target. Lying just Ne of Propus (Eta Gem) it is a supernova remnant which, with long exposure images, looks just like a jellyfish complete with tendrils!

Good Hunting and I hope to see you tomorrow evening at the society's monthly meeting.

Best Regards

David