Indholdsfortegnelse for June 2020 i BBC Sky at Night

What astronomers had previously thought to be an exoplanet might be something rarer – the remains of two comet-like objects which have crashed together. The former planet, Fomalhaut b, was first announced in 2008 after four years of Hubble observations tracked a bright point moving through the planetary disc of a distant star. At the time, astronomers thought this was a newly formed exoplanet, making it the first one to be detected directly through visual observations. Researchers continued to observe the ‘planet’ every few years as it made its way around the star but were shocked in 2014 to discover that it had vanished. After looking back at the last decade of observations, a team of exoplanet astronomers realised that Fomalhaut b had actually been fading for several years. They…

As the world continues to battle the COVID-19 pandemic, the space sector is on hand to aid in the fight. In the UK, a fund of £2.6m has been made available to the space industry to help fund high-tech products which might aid the NHS response to the pandemic. These projects include a satellite system helping GPs conduct virtual consultations and software which can diagnose cancer more quickly. Elsewhere in the world, engineers at NASA’s Jet Propulsion Laboratory who normally build spacecraft are instead designing new ventilators specifically designed for COVID-19 patients. Meanwhile, colleagues at Armstrong Flight Research Center have designed a special pressure helmet to treat those with more minor symptoms. “The current circumstances challenge the space business community to show just how much it can offer, to help…

NASA has taken another step towards returning to the Moon by contracting Blue Origin, SpaceX and Alabama-based Dynetics to build the next generation of lunar landers, the agency recently announced. The three spaceflight companies have each been tasked with designing and building a new landing system that will carry astronauts to and from the lunar surface. The move is part of the space agency’s Artemis programme – an initiative aiming to return astronauts to the Moon, one of whom will be the first female moonwalker, by 2024. “We are on our way,” says Douglas Loverro, associate administrator for NASA’s Human Explorations and Operations Mission Directorate. “With these awards we begin an exciting partnership with the best of industry to accomplish the nation’s goals. We have much work ahead, especially over…

Yes, you read that correctly: Sky at Night Magazine is encouraging you to look at clouds. But aren’t clouds the mortal enemies of sky-watchers? Aren’t they the Voldemort to our Harry Potter? Not these clouds, no. Although it has to be said some astronomers and sky-watchers don’t consider noctilucent clouds (NLCs) to be astronomical and dismiss them as being “just clouds” or worse, “the poor man’s aurora”, many amateur astronomers enjoy observing and photographing them just as much as others enjoy peering through their scopes at misty spiral galaxies and glittering star clusters. However, unlike those much-loved deep-sky objects, NLCs are not visible all the time; there is an NLC season which runs between the end of May and the start of August every year. This is part of their…

NLC displays are beautiful to the naked eye but they look even better through a pair of binoculars. The same binoculars you use to look at the Pleiades, M31, and the phases of the Moon will give you very clear views of the subtle shapes, structures and forms NLCs can take, and will enhance their lovely colours too. They will also help you see how bright NLC displays change shape through the night. And they are extremely useful for helping you spot the first faint signs of a display before it becomes obvious to the naked eye.…

On the night of 24 May 2019, astronomers looked up to see a chain of bright lights moving across the darkness. While the flash of planes and satellites are familiar sights in the night sky, no one had ever seen so many, so bright and so close together. As images and videos of the strange sight made their way around social media, the culprit soon became apparent – 60 satellites released by spaceflight company SpaceX as part of its Starlink project. And this was just the first batch of many. Starlink is a megaconstellation – a network of satellites in low-Earth orbit. Its goal is to supply cheap internet access around the entire globe, particularly in rural and remote areas beyond the reach of traditional connections. The ‘mega’ part of…

All month June and July are the best months for trying to spot elusive noctilucent clouds (NLCs). Turn to page 43 for more information. 2 Tuesday Look out for the clair-obscur effect called Cassini’s Moon Maiden this evening. This light and shadow play at the southern end of the Jura mountain range is supposed to resemble a girl with flowing hair looking across the bay. Best seen in an inverted (south-up) view. 3 Wednesday Venus reaches inferior conjunction but is sadly too close to the Sun for safe viewing. After today this iconic planet returns to the morning sky. 4 Thursday Mercury reaches greatest eastern elongation, appearing separated from the Sun by 23.6° in the evening sky. Try and catch it around 22:30 BST (21:30 UT) low above the northwest…

DON’T MISS Lunar occultation OF VENUS BEST TIME TO SEE: 19 June from 08:20 BST (07:20 UT) until 10:00 BST (09:00 UT) Venus has been a dramatic object in the evening sky so far for all of 2020, but this month it’s notable because of its absence. The reason for this is that it is passing around a part of its orbit which is closest to Earth. As it does so it lines up with the Sun in the sky to reach a position known as inferior conjunction; inferior simply indicating that Venus is between Earth and the Sun. On rare occasions Venus appears to pass in front of the Sun at inferior conjunction. Known as a transit of Venus, this won’t happen again until 2117. For many inferior conjunctions…

1. Zubenelgenubi 10 x 50 Did you know that (nearly) everyone’s favourite star name is a nice easy binocular double star? Shining at mag. +2.7, Zubenelgenubi (Alpha-2 (a2 ) Librae) – the name means ‘the southern claw’ – is visible to the naked eye. Binoculars easily reveal the mag. +5.2 companion, Alpha-1 (a1 ) Librae, 3.5 arcminutes away. Although they are both around 75 lightyears distant, they may not be a true binary star. 2. Delta Librae 10 x 50 The variable (mag. + 5.8 to mag. +4.4) Delta (ð) Librae lies 8° north of Zubenelgenubi and is an eclipsing binary star. This is a pair of stars, orbiting their common barycentre, in which the fall in brightness, which takes about six hours, occurs as the larger dimmer star occults…

Green lasers are very useful as star pointers when we show people around the sky at star parties and outreach observing events. But there has been concern about their use, especially in built-up areas and near airports, with some astronomical societies banning them at events. The advent of inexpensive but powerful compact LED torches with adjustable focus gives us an opportunity to make a safer alternative. Although these LED torches are focusable, they do not produce the narrow pencil of light that makes a good pointer. To achieve that we need to extend the torch and replace the existing lens with one of a greater focal length. You will need a torch with a bright LED because our conversion will result in a beam that is dim: we used one…

The Moon’s angular diameter in our sky is about half a degree. Hold your little finger up at arm’s length and this is approximately 1° wide. You could hide two full Moons side by side behind it. With a huge sky to wander around in, it’s not surprising that the tiny Moon rarely hides the planets. Actually, ‘huge sky’ is misleading because the Moon’s apparent movement is restricted to a 10°–wide corridor, centred on the ecliptic. The ecliptic is a great circle that represents the plane of Earth’s orbit and the apparent path of the Sun against the stars over a year. All of the main planets and the Moon have orbits aligned to the ecliptic. Each has a tilt which means it travels in its own narrow corridor around…

When touch-screen imaging is enabled, we were amazed at how lightly we needed to touch the LCD screen to take a shot – a light tap rather than a firm prod. There was no risk of nudging the camera to take an exposure, or while changing ISO and exposure settings.…

Where did you spend your year cut off from the rest of the world? Concordia is one of three permanent all-year research facilities in Antarctica. Jointly operated by scientists from France and Italy, it also hosts European Space Agency (ESA) scientists and is located 3km above sea level on the Antarctic Plateau. I spent 14 months with a crew of 12: a 50/50 mix of scientists and technical teams of different nationalities and backgrounds. This included an isolated nine-month period over winter when we studied with ESA. What research were you conducting? I am a medical doctor but my main role for ESA was psychological and physiological research. The base is situated at a high altitude, equivalent to 4,000m at the equator, with very thin air. We measured the crew’s…

A star has survived a close brush with a black hole, only to be slowly devoured. Recent observations from X-ray telescopes Chandra and XMM-Newton have revealed the dramatic story of a red giant which drifted too close to the black hole at the centre of its galaxy. The star was captured by the black hole, which then stripped away the outer layers of the red giant’s gas until only a white dwarf remained. The black hole continues to nibble away the star’s gas, creating bright bursts of X-rays as it does so. As the star continues to lose mass, it slowly drifts away, but it will never quite escape the black hole’s grasp. “The black hole will eat it more and more slowly, but never stop,” says Andrew King from…

A few weeks ago no one could have predicted the way we would produce this month’s Sky at Night programme – our 800th – or how much it would change from the original plan. We were going to send Maggie and Chris to Chile, as guests of the European Southern Observatory, to look at the optical telescopes they operate in the Atacama desert; and to report on the progress of the Extremely Large Telescope – soon to become ‘the world’s biggest eye on the sky’. Of course, events took over and we had to postpone the trip due to the COVID-19 pandemic, though we’re still hoping to film later in the year when everything returns to normal. Instead, our amazing production team ended up making a very different programme from…

Mission Space If you’re looking for some fun but educational content to keep your young intrepid astronauts occupied, these five Mission Space episodes from children’s science presenters Maddie Moate and Greg Foot could be just the ticket. Best suited to kids of 10 and under, they’re part of the Let’s Go Live YouTube video series with a mix of facts, guests, quizzes and hands-on craft activities. The episodes are: Mapping the Solar System, How to Make a Fruit Salad Solar System, Live Tour of a Spacesuit, Three DIY Rockets to Make at Home and Landing on Another Planet. It live streamed in April and although the interactive chat is no longer active, the episodes still make entertaining viewing. The craft activities are simple and thankfully involve items you’ll likely already…

Major displays of NLCs, with activity reaching well above the horizon throughout the night, will be visible from your garden or even your bedroom window, as long as you can see the sky to the north. However, smaller displays which hug the horizon will be much harder to see if your view north is obscured by neighbouring houses, tall buildings or hills. You’ll have the best view of a display if you can get to somewhere with a low, flat horizon and a clear view sweeping from west to east. And obviously the less light pollution you have, the better.…

You don’t need an expensive or complicated camera to photograph NLCs; many phones now have cameras that are more than good enough to take lovely photographs of bright displays. Hold your phone as steady as possible, make sure that you include some foreground objects in your pictures for scale, and try your phone camera’s night mode setting if it has one. If you can, frame your photos so the NLCs are reflected in a river or a lake, or have trees or buildings silhouetted against them. If a display is too big to fit on one single photo, try your camera’s panorama mode.…

Amateur stargazers were one of the first groups to realise the impact of Starlink satellites on views of the night sky. “The first day of the launch I got loads of messages asking what was going on,” says astrophotographer Alyn Wallace. “They’d just seen the first train of satellites coming over the UK and were trying to work out what they’d just seen.” For most visual observers, the effects shouldn’t be too bad. The satellites are currently only visible to the naked eye from dark-sky sites, and SpaceX seems committed to reducing their brightness below even that. Meanwhile, for those looking through a telescope, a satellite drifting through the eyepiece should be a rare and momentary annoyance. The community which will be worst hit, however, are astrophotographers, especially those taking…

PICK OF THE MONTH Jupiter Best time to see: 30 June, 02:00 BST (01:00 UT) Altitude: 15° Location: Sagittarius Direction: South Features: Belts, Great Red Spot, atmospheric disturbances, Galilean moons Recommended equipment: 150mm or larger Jupiter is the largest planet in the Solar System, an example of an object known as a gas giant. When you look at it through a telescope, you’re looking at the top of the planet’s extensive atmosphere. Here you can see all sorts of atmospheric phenomena. Spinning once on its axis in just shy of 10 hours, the planet bulges at its equator, appearing oblate even through a small instrument. Most obvious visually are the two dark bands that encircle the planet to the north and south of the equator. These are known as the…

Minor planet 7 Iris reaches opposition on 28 June when it will appear at a binocular-friendly mag. +8.8 in Sagittarius. It starts its June track to the west of the lip of the Teaspoon asterism, about 40 arcminutes west of mag. +3.5 Xi2 Sagittarii and just to the north of mag. +5.7 33 Sagittarii. On 1 June, Iris will be shining at mag. +9.6. As it approaches opposition on 28 June it will pass about 1.5° south of the rich, mag. +4.9 open cluster M25. Iris has a mean diameter around 241km, its tri-axial ellipsoidal measurements being 268 x 234 x 180km. A tri-axial ellipsoid is a three-dimensional, oblate ellipsoidal shape which offers a convenient way to approximate the dimensions and size of an irregular shaped body such as an…

With Jupiter now clearly visible low in the south, this month’s challenge is to capture some of its fainter moons. Jupiter has a lot of moons; 79 at the last count. You’d never know looking at the planet through an amateur scope because only four of them are easy to spot. These are the four so called Galilean moons, Io, Europa, Ganymede and Callisto. The reason for the apparent disparity between the total moon count and the number seen through the eyepiece is down to size. The four Galileans are huge and appear bright, the remaining 75 are small and quite faint. However, four is not the limit for amateurs and with a bit of vigilance, others may be seen or imaged. The moons which lie within the magnitude reach…

Looking directly at the solar disc is dangerous and it can potentially cause permanent damage to your eyesight. You should never look at the Sun directly, especially through an unfiltered telescope or binoculars. Fortunately, there are many methods you can use to look at the Sun safely. One is to project the view through a telescope onto a white piece of card with a secondary card to act as a sunshade to create a dark area – that will help improve contrast. Remember to cap off any optical finder to ensure no one looks through it accidentally. You can also buy a Hershel wedge or prism, which replaces your diagonal in a refractor and transmits a much reduced, safe amount of light to the eyepiece or camera. There are also…

Astronomers can pinpoint the time and location of an eclipse to the millisecond. “What you need is to have an accurate ephemeris, a computer program that can accurately predict where the Sun and Moon are, with respect to Earth,” says Fred Espenak, a NASA Scientist Emeritus best known for his work on eclipse predictions, who runs the website MrEclipse.com. That means knowing where all three celestial bodies are in three dimensions. “Then you can predict where the Moon shadow is, since it’s always pointing away from the Sun.” Figuring out where that shadow is in space, where it’s going to be, when it’s going to intersect Earth’s surface, and how it moves across the surface – all in 3D – is then calculated using spherical trigonometry. “It’s all worked out…

STEP 1 Decide how to image the event. A wide-field setup allows you to grab the entire lunar crescent with a small Venus. A scope with a focal length around 1,000mm is ideal. A lower focal length works too but the Venusian crescent may become lost, while a longer focal length shows the crescent but is trickier to work with. STEP 3 Once Venus is in view, focus on it as accurately as you can. If you do this well before the occultation, make sure you re-check the focus as the heat of the day can cause it to drift out. If you’re planning to use a high-frame-rate planetary camera consider using an infrared pass filter. This will darken a blue sky and improve STEP 5 A short exposure will…

HUBBLE SPACE TELESCOPE, 24 APRIL 2020 A life and death tussle never looked so beautiful. This is the remarkable ‘Cosmic Reef’, part of the vast Large Magellanic Cloud, the third closest galaxy to the Milky Way. On the right is NGC 2014, a glowing red cloud of mostly hydrogen gas blown apart by a cluster of hot, newborn stars, unleashing fierce winds and creating structures reminiscent of brain coral. On the left is its distinctive blue sibling, NGC 2020, formed when a single star – a monster 15 times more massive and 200,000 times more luminous than the Sun – was ejected from the stellar nursery. This short-lived colossus, Wolf–Rayet star HD 269748, is shedding its external envelope in a superbubble of blue gas. In a relatively short time, it…

One of the most Earth-like exoplanets ever found has been pulled from anonymity after almost being overlooked. In a recent paper, a team of astronomers re-evaluated data from the Kepler Space Telescope, looking for potential planetary signals that had mistakenly been thrown out as an unwanted artefact. The uncovered planet, Kepler-1649c, is a world around 6 per cent larger than Earth in the habitable zone of a red dwarf star 300 lightyears away. “In terms of size and likely temperature, this is the most similar planet to Earth that has ever been found with Kepler,” says Jeff Coughlin from SETI Institute, who took part in the study. “The more data we get, the more signs we see pointing to the notion that potentially habitable and Earth-sized planets are common around…

Interstellar comet 2I/Borisov has been found to have high levels of carbon monoxide, giving a hint to what kind of planetary system it originated from. The recent discovery came after astronomers analysed images from the Hubble Space Telescope, taken when the comet flew through the Solar System in late 2019. Borisov attracted the attention of astronomers after its trajectory suggested it started life around another star. As comets are thought to be the icy remnants of when the planets first formed, it gave planetary scientists a unique chance to look at some of the chemical building blocks of another planetary system. “We’ve been studying the composition of comets here for decades and using this information to understand how planets in our Solar System formed and evolved,” says Kathleen Mandt from…

“We have better images of the lunar surface for crater counting, and more precise isotopic measurements of the Moon rocks” When planetary scientists are trying to understand the surfaces of other worlds in our Solar System, and the processes that form and shape them, the ages of different features is a crucial detail. It’s straightforward to deduce the relative chronology of different plains of volcanic rocks or sedimentary deposits by looking to see which one appears to lie on top of or cut across the other. But this only tells you that one splodge of rock is older or younger than its neighbouring formations. What would be so much more useful to know is the absolute age of particular surfaces – for example, this volcanic plain is 200 million years…

On the 28 June 1977 episode of The Sky at Night, Patrick Moore spoke with astrophysicist Jocelyn Bell Burnell about the rapidly expanding field of gamma-ray astronomy. Gamma rays are high energy photons created by equally energetic events. For the first half of the 20th century, astronomers theorised that violent events such as supernovae could produce gamma rays. However, Earth’s atmosphere does a good job of absorbing such radiation, making it difficult to observe the rays from the ground. By the early 1960s, astronomers were finally able to put gamma-ray detecting satellites into orbit, where they could detect the rays. The first was NASA’s Explorer 11, which picked up 100 photons coming from all over the Universe, suggesting some kind of gamma-ray background. The most surprising discovery came in the…

It’s 60 years since a radio telescope was first used to search for alien life. Will a new generation of technology help us make contact with extraterrestrials? The year 2020 will mark the 60th anniversary of the first scientific search for life beyond the Solar System. Between April and June 1960, Frank Drake used the Green Bank Radio Telescope in Virginia to search two stars, Tau ( t ) Ceti and Epsilon ( e ) Eridani in an attempt to catch any intelligent signals emanating from potential planets around them. He had no success, but ‘Project Ozma’ started a long running search that has captured the imaginations of millions. Life in the Universe is a concept that has been long debated. The technological progress of the last century has given…

A modern DSLR camera will take beautiful photos of NLCs. Fit it with a wide-angle lens, set it to manual so you can take long exposures and mount it on a tripod to keep it steady. With the aperture as wide as possible, set the ISO to 800 and take a few test exposures of several seconds. If the NLCs are burned out and no detail is visible, reduce the ISO and the exposure time until the photos show the display properly. Use a longer lens and higher ISO to record fine structure within NLCs. You could even try an NLC selfie, showing you silhouetted against them.…

For astronomers, the reasons for keeping satellite light pollution down are obvious, but they are not the only one with an investment in the night sky. “There are cultures around the world who may not be heavily involved with space, but who live in less urbanised environments and have a strong tradition associated with the night sky,” says John McDowell. “These people might be put out if the night sky was changed suddenly without them being consulted.” One major scientific enterprise which could suffer is the search for near-Earth objects, as the conditions which are best for illuminating space rocks are the same for illuminating satellites. With thousands of satellites moving across the sky, it will be difficult for surveys to pick out the motions of an asteroid, making it…

KEY TO STAR CHARTS When to use this chart 1 June at 01:00 BST 15 June at 00:00 BST 30 June at 23:00 BST On other dates, stars will be in slightly different positions because of Earth’s orbital motion. Stars that cross the sky will set in the west four minutes earlier each night. How to use this chart 1. Hold the chart so the direction you’re facing is at the bottom. 2. The lower half of the chart shows the sky ahead of you. 3. The centre of the chart is the point directly over your head. Sunrise/sunset in June* Moonrise in June* Lunar phases in June MORE ONLINE Paul and Pete’s night-sky highlights Southern Hemisphere sky guide…

Alkalurops (Mu (m ) Bootis) is located close to the eastern border of Boötes, just to the northeast of the Kite asterism which represents the main body of Boötes the Herdsman. The name Alkalurops means ‘a herdsman’s staff’ or ‘club’. As with many of the stars which appear as single objects, under close scrutiny Alkalurops isn’t alone but rather a pair of double stars which may or may not be physically connected. The two pairs are designated Mu-1 ( m1 ) and Mu-2 ( m2 ) Bootis. The Mu-1 pair to the west carry the official name Alkalurops and appear close as seen from Earth with a narrow separation of 0.08 arcseconds, too close to be separated by amateur equipment. To us the primary appears as a F0 V star…

1 M13 The Keystone asterism plays host to the spectacular object M13, the Great Globular in Hercules, located one third of the way along the line from Eta (e) to Zeta (z) Herculis. M13 is a treat through any instrument. A 150mm scope partially resolves the cluster’s core. Look out for three dark dust lanes converging to form a pattern called ‘the propeller’ southeast of the core. A 200mm scope shows more stars individually across M13’s centre, larger apertures only improving its resolved appearance. Although globulars are often described as being ‘fully resolved’, this means individual stars are seen in front of the hazy, still unresolved core. Look directly at the core using a medium to high power and towards the edge of vision you should see ‘strings’ of stars…

A Go-To equipped telescope, or one equipped with setting circles on an equatorial mount, can be used to find planets and stars in daytime. In either case, if the Moon is near to your target, calibrate on it first then offset to put the target in the eyepiece. You can also use the Moon to focus first, as an even slightly out of focus planetary disc or star can be virtually impossible to see. If the Moon is not available, you can still spot the five brightest planets and bright stars with care by using a Go-To system or with setting circles. With the latter you may have to use the Sun as a guide instead, but ensure you use safe solar filters. Then when you have moved the scope…

Today everyone’s familiar with the popular, informal names given to full Moons – there’s a different one for each month – June’s full Moon is called the Strawberry Moon. But there’s a problem with these names, because our calendar of 12 months isn’t in sync with the lunar cycle – and in 2020 it really comes home to roost. For the most part our calendar and the lunar cycle are in sync and we get a full Moon every month, but sometimes there are two full Moons in one month and possibly none in another. And this mismatch gets more complicated because one full Moon does have a fixed definition – the Harvest Moon. These problems are illustrated by this year’s full Moons (see list, right) and the way the…

Step 1 You can establish the required length of the tube by setting the torch to half its focal range, 5m or more from a blank wall, and holding the lens in front of it to give a sharp image of the LED on the wall (shown inset). Step 3 Use a sharp saw to cut the pipe. An ordinary handsaw will suffice for plastic pipe but, if you are using metal pipe, you will need a hacksaw with a blade of 24 teeth per inch or finer. Use a file to deburr the cut edge. Step 5 Clean the lens and put it into place, then make a thin sausage of mouldable glue. Carefully feed this around the inside of the tube, in contact with the lens, then smooth…