BBC Sky at Night

BBC Sky at Night September 2017

Sky at Night magazine is your practical guide to astronomy. Each issue features the world’s biggest and best night sky guide complete with star charts, observing tutorials and in-depth equipment reviews to ensure that amateur astronomers never miss those must-see events.

United Kingdom
Immediate Media Company London Limited
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12 Issues

in this issue

1 min.
this month’s contributors include...

Maggie Aderin-Pocock Sky at Night presenter Maggie joins the hunt for space rocks in an unlikely location – the roof of the Norman Lockyer Observatory. Page 21 Ben Evans Space exploration expert Ben recounts the highs of the Cassini mission at Saturn, which comes to an end this month with a death-dive into its atmosphere. Page 32 Daniel Lynch Eclipse chaser Daniel explains how to take your eclipse photos to the next level with a tutorial on coaxing detail from the Sun’s corona. Page 84 Jenny Winder Science writer Jenny charts the Voyager mission’s incredible quest to the outer Solar System and into the unknown of interstellar space. Page 67…

2 min.

Now that the evenings are once again starting earlier and we can look forward to longer nights, it could be time to consider observing from somewhere more remote – to do some wild astronomy. Whether you are excited by an expedition up to high moorland or want to make an evening trip just out of town, on page 38 Will Gater is your guide to how to pull this off successfully and safely. Dark skies await! Saturn is sure to be one of the targets to view in darker skies this month, and on the 15th the Cassini mission at the Ringed Planet comes to a dramatic end with a final plunge into the planet’s interior. Ben Evans looks back at 13 years of science at Saturn and explains why destruction…

1 min.
skyatnight lots of ways to enjoy the night sky...

TELEVISION Find out what The Sky at Night team will be exploring in this month’s episode on page 19 ONLINE Visit our website for reviews, competitions, astrophotos, observing guides and our forum FACEBOOK All the details of our latest issue, plus news from the magazine and updates to our website PODCAST The BBC Sky at Night Magazine team discuss the latest astro news in our monthly podcast iPad/iPhone Get each month’s issue on your iPad or iPhone, now with bonus video and images TWITTER Follow @skyatnightmag to keep up with the latest space stories and tell us what you think…

3 min.
juno on the spot

September marks 40 years since the launch of the Voyager spacecraft, which visited the four outer giant planets of the Solar System and 48 of their moons. It was humanity’s reconnaissance mission, enticing us with incredible planetary encounters and inspiring the current era of planetary exploration: Cassini, New Horizons and most recently the Juno mission to Jupiter. In July this year Juno celebrated its own anniversary – one year since its arrival in Jupiter’s orbit – with a close flyby over the Great Red Spot, gifting us with an unprecedented view of the huge storm. On 11 July at 01:55 UT it flew within 9,000km over the ruddy anticyclone, capturing images of it with the JunoCam instrument. The Great Red Spot appears to be shrinking, but it’s an astounding 16,350km wide, which…

1 min.
smallest star ever discovered

The tiniest star ever observed, with a diameter slightly larger than Saturn, has been discovered 600 lightyears away. EBLM J0555-57Ab, a red dwarf in a binary system, was found by researchers on the WASP exoplanet hunting experiment, who were looking for planets passing in front of a larger star now thought to be its stellar companion. “Our discovery reveals how small stars can be,” says Alexander von Boetticher, the lead author of the study, from Cambridge’s Cavendish Laboratory and Institute of Astronomy. “Had this star formed with only a slightly lower mass, the fusion reaction of hydrogen in its core could not be sustained, and the star would instead have transformed into a brown dwarf.” Red dwarfs are thought to be fertile grounds for exoplanet hunters, as the dim light of the…

1 min.

This new star is smaller than Saturn, but the team estimate it has the mass of 85 Jupiters. That makes this one of the densest objects known – not quite up there with neutron stars and black holes, but ahead of almost everything else. That density is why this is a star not a planet. At the surface the star is nearly as hot as the Sun, and at the star’s core the temperature is high enough for the nuclear fusion of hydrogen into helium to proceed. That’s about as close to a sensible dividing line between star and planet as there is. Large planets like Jupiter do produce some internal heat, but are nowhere near hot enough for hydrogen fusion. The importance of EBLM J0555-57Ab is that it lies very close…