JUNE finds us heading into the winter season, which brings the longest night and shortest day on the 22nd.
Over to the northwest at 7.30pm, you might catch Procyon in Canis Minor just setting, then arcing up near the ecliptic comes Cancer, then Regulus in Leo (or the Sickle) now in the northwest.
And while there are many stars there, few really standout until you come to the bright star Spica in the constellation of Virgo, high up and nearly north at this time of the night. Then lower and further east comes Arcturus in Bootes, the Herdsman, and that’s it for the northeast region.
Around to the south, now is the perfect time to take in the most visible extent of our Milkyway galaxy, which contains an estimated two-to-four billion stars of many different sizes and temperatures. Through dogged perseverance, early astronomers gradually categorised them into groups called the Hertzsprung-Russell diagram.
The diagram was created around 1910 by Ejnar Hertzsprung and Henry Norris Russell. Working completely independently, the two astronomers came up with similar results that found the stars we call main sequence stars. These are stars that are very similar to our sun, which is slightly smaller than the vast number of others.
Our sun having eight main planets orbiting it gives an indication there is possibly 10 billion other planets in our galaxy alone. Astronomers consider our Sun like the porridge in the Goldilocks nursery story. Not too hot and not too cold, but just right. Our Earth is in the Goldilocks zone, not too close, and not too far from our sun, where it is cool enough for water – the crucial element for life – to condense.
They use this as a model to search for other Earth-like planets in our galaxy. During its nearly 10 years service, the Kepler Space Telescope observed 530,506 stars and detected 2662 planets, mainly gas giants, larger than Jupiter.
Because of the great and varying distances they are from us makes Earth-like planets very hard to find. But the search goes on and, more recently, two Earth-like planets were discovered in very speedy and close orbits around their stars making them far to hot to sustain any forms of life.
Luckily, their orbits were in the telescope’s line of sight, and as they passed in front of their star, spectrography analysis revealed they had water vapor in their atmospheres, positive proof there must many many other rocky planets in the Goldilocks zones of the billions of main sequence stars out there in our galaxy.
Coming up from the east, the heart of our galaxy with the densest concentration of stars in Sagittarius has come into view, just below the sting of Scorpio, which is has rotated slightly upward now and easy to find with the red giant Antares in Scorpio’s body.
Higher up lies the two pointers, Alpha and Beta Centauri, part of the Centaurus Constellation of the half-man-half-horse. They in turn point to the very familiar, for us, Southern Cross. Continuing upward we come to the Carina Nebula, a vast area where many hundreds of stars are being formed from the very rich remnant gases of past super-nova cataclysms.
There is a very large and unstable star there, Eta Carina. It most likely has a companion star that could explode at any time and is being monitored very regularly with the large telescopes. The activity there is obscured by a very dense cloud of gas equal to the size of our Solar System, which was the result of a massive explosion that occurred in1837 when it flared so bright, it was visible in the daytime.
During the past month, the bright lights – the planets in our own solar system – have continued to rearrange themselves so that now both Mercury and Venus are rising either side of the sun at 9.14am and 6.09 respectively. This means they are too close to the Sun to be seen, though Venus, lingering in the morning sky, may still be spotted in good conditions at 1.638 astronomical units distance.
Mars is very far off now, presently 2.498au, rising at 9.21am and setting at 6:44pm, just 13 minutes after Mercury. Giant Jupiter is putting on a grand display right now, with Earth having just passed at the closest point this time around, on June11, and right now it is just 4.285au distant. Now is the best time to view it through a telescope, not only to see the turbulent clouds of its gaseous atmosphere but the ever-changing positions of its four main Gallilaeon moons, Io, Europa, Ganymede, and Callisto.
Over recent years, the number of smaller objects discovered in Jupiter’s orbit has grown to 79. Due to their orbiting at many obtuse angles, most of these are likely to be captured asteroids. The man-made satellite, Juno, is still orbiting Jupiter, adding to the growing amount of information and fabulous images we have been getting from NASA.
We are also rapidly catching our final bright light, Saturn, rising right behind Jupiter at 6.47pm on June15. It will be at opposition (nearest earth) on June 28, presenting itself for the best possible view over this period. The best time to view them is as they cross the meridian at midnight. This is when your view is at right angles through the least of the Earth’s atmosphere.
By Norman Izett