David Grennan, an amateur from Dublin, has thrilled astronomers with his discoveries of supernovae in distant galaxies. Here is the inside story of his admirable achievements. Astronomy is one of the few sciences where talented amateurs can make important contributions. As example you have only to look at the recent Read more…
In, say 1975, there was only one kind of ‘stuff’ in the Universe, matter made of protons and neutrons. By 1985 there was a consensus that this was not enough, the gravity of the stars in galaxies was not sufficient to hold them together. Something else was there, vast, mysterious Read more…
We all love bright and showy spiral galaxies! So much so, that we tend to overlook the elliptical galaxies which make up about 30% of the galaxies out there. Smaller than spiral galaxies, elliptical galaxies may be full of stellar living fossils, surviving virtually unchanged from an older cosmic era. Read more…
This fluffy pink blob is the star-forming region LHA-120-N 11 in the Large Magellanic Cloud some 170 000 light years from the Sun. N 11 (occasionally called the Bean Nebula) is about 1000 light years across. Take a moment to think just big that is! What is the source of Read more…
Here’s how rainbows are made. Some 13.7 billion years ago, a mere millionth of a second after the Big Bang, the first hydrogen and helium nuclei condensed out of a hot, dense soup of quarks and gluons. It took another 380 000 years or so for conditions in the ancient Read more…
Searching for life elsewhere in the Universe is a fascinating endeavour. It is is not a recent idea either. Astronomers in the 1800s used telescopes to search for signs of life and even civilization elsewhere in the Solar System. Some even believed they saw signs of intelligent life on Mars Read more…
About 100 000 light years across, Messier 66 is the largest galaxy in the “Leo Triplet”, three interacting spiral galaxies about 33 million light years from us. This new Hubble Space Telescope image shows that M66 seems to have been through the mangle. Misshapen with an off-centre core, the galaxy is not a neat spiral. It has been tugged by the gravitational pulls of its neighbours’, NGC 3628 and M65, and indeed may have suffered a close encounter with NGC 3628 a billion years or so ago which ripped away hundreds of thousands of stars.
Located just under the line between Regulus and Denebola, M66 and M65 can be seen with a small telescope or 10×50 binoculars in the spring. Why not go out to see if you can find these distant islands of stars?
(What is a Messier object? You can find out in this issue of Astronotes)
Dark matter and its part in the evolution of the Universe is revealed by new data collected by the Hubble Space Telescope. This image could be taken for a lurid TV special effect (the Lights of Zetar perhaps?) but it may actually represent proof of that elusive and mysterious entity, Read more…
Fifty years of SETI with radio telescopes has so far proved negative. We have found no messages of peace and goodwill, no galactic internet, no extraterrestrial propaganda or advertising. No starships full of aliens have arrived on Earth to befriend us or to eat us, while our galaxy seems Read more…
Astronomers in search of really, really big stars look to the Tarantula Nebula. Also known as 30 Doradus (or even NGC 2070), this is a very active star-forming region in the Large Magellanic Cloud (about 170 000 light years from us). Just how big are the stars in the Tarantula? Read more…