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Archive for May, 2012

3 May 2012

Since we wrote the last blog, we have joined a Star Hoppers group led by our US mentor Greg. Most of the members are on the east coast of the US. We are the only two, as far as I know, Down Under. The aim of the group is to apply the classic advice of Sherlock Holmes – learn to “observe,” not simply to “see.”

And what should we observe in the first two weeks of May?

 “Good targets for viewing under dark skies are the Beehive (with binoculars or a low power scope), several double stars in Cancer and Leo or the galaxies in Leo.”  

We have to pick 3 – 5 targets on any given night.

The targets for May are fortunately also in constellations in our southern sky.

Constellations of Cancer and Leo

Stellarium image of constellations of Cancer and Leo (click on image to enlarge)

Waiting, waiting

Primed and ready – we waited for the weather to give us a break.

When weather reports of the last few months promised clear skies, they often didn’t mention the evening clouds that creep in, uninvited, and destroy any chance of viewing the stars.  So we’ve invented a new game to amuse ourselves: it’s called “Wither goes the weather?”

On the evening of the 3rd May, around 8 pm, we were pleasantly surprised to find the sky was clear of pesky clouds. When we walked out on to car deck observatory the panorama was breath-taking even with lights on everywhere and moonlight bathing the street. And the air was cool and calm. Perfect for viewing!

Dish of the sky

Stellarium image: Dish of the sky (click on image to enlarge)

Sure our view wasn’t quite as detailed as this, but with all those fairly large objects in view, we were very excited.

Starting from north – Mars was pretending to be one of the stars of Leo, forming a neat triangle with Regulus and Algieba.

Moving past the fat Gibbous Moon, and going east was Saturn, a golden brooch on the skirt of Virgo.

Looking south over Francis Street were the Pointers doing their job of showing us the Southern Cross.

Southern Cross and Pointers

A slide along the Milky Way and we were looking west at Canis Major (Big Dog) lying on his back wearing Sirius like a trophy on his chest. And caught in the moonlight (or should I say despite the moonlight) a hare, Lepus, being chased by the Big Dog. What a beautiful constellation this is! A neat curve of stars.

Just below the Big Dog is his master Orion slipping down sideways behind the trees!

View of western sky

Our photo: View of western sky (Click on image to enlarge

Spoilt for choice

How to choose three targets? Spoilt for choice, weren’t we? So we did what one does at a smorgasbord crammed with too many delectable dishes. We decided for our first night of star hopping to sample every big star and planet we could see and look for doubles and galaxies and clusters before we committed ourselves to three.

 Using our binoculars we star-and-planet hopped. With the Moon between Leo and Virgo, we were lucky to see Regulus and Algieba, but swinging to the Cross we saw the Jewel Box displaying its contents near Beta Crucis. And in the vicinity was the king of globular clusters – Omega Centaurus.

Going down the Milky Way, watered down by the light of the Moon and the lights on in every home in Francis street (people don’t believe in curtains or blinds), we looked for M41 in Canis Major, and found it rather faint. Caught M42 in Orion’s sword just before the Hunter slipped off on his perpetual chase of the Scorpion.

With the sky still clear at 8.30 pm we decided it was time to bring out the scope and look at the planets. Mars was a nice round reddish disk, but Saturn, despite the light of the Moon, beat the god of war in the beauty stakes. Saturn is certainly the pin-up boy of the planets! We could just see its moon, Titan; the other moons were drowned out by the light of the Moon.

Had we been able to see them, this is what we would have seen.

Saturn with moons

We’ll keep that treat for another night.

Turning our sights to the Moon

Having had our fill of stars and planets we turned the scope with the 6mm eyepiece on the Moon. OMG! The angle of the light from the sun lit up craters and mares perfectly, casting shadows to show them in 3D. We have never seen crater Aristarchus with Vallis Schroteri and  crater Herodotus  in such good light. It was the feature of the night.

Some features of the Moon

Another striking feature in this light was the Bay of Rainbows with crater Bianchini clearly visible as were the other four or five craters in the neighbourhood. And then looking toward the edge of the Moon was a rather angular crater with a prominent peak. I think it is Babbage, or perhaps Pythagoras.

We could even see the Rectii range, an unusually straight range in the Sea of Showers.

Blindingly brilliant were Copernicus, Kepler and up at the top Tycho. But another crater that stood out very clearly, so that we could even discern where its rim is broken, was Gassendi on Mare Humorum. With Gassendi A, this crater looks like an engagement ring with a big diamond.

After a month’s starvation of night sky viewing, we feasted on this evening’s gifts of a clear and still night.  An hour and a half of uninterrupted viewing was more than we hoped for, so when the clouds came over at 9.30 pm, we folded our scope without a word of complaint.

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