Indholdsfortegnelse for July 2023 i BBC Sky at Night

The latest astronomy and space news, written by Ezzy Pearson BULLETIN Bloated star gives a dusty belch as it engulfs one of its orbiting planets A star has been caught in the act of swallowing one of its planets for the first time, giving a preview of our own Solar System's fate. The star, ZTF SLRN-2020, first attracted attention in May 2020 when the Zwicky Transient Facility in California – which scans the sky nightly – detected it had brightened by over 100 times in just 10 days. Initially, astronomers thought the brightening was caused by two stars merging. However, the star remained bright in the infrared for 100 days after the initial outburst, indicating it was surrounded by a cloud of cold material. “When a star brightens it usually…

A distant exoplanet could be surrounded by a steamy atmosphere, according to new measurements by the James Webb Space Telescope. The planet, GJ 1214b, is a miniNeptune – the most common type of planet in the Galaxy – in a close orbit around a red dwarf star, taking just 1.6 days to orbit. The planet is shrouded in a cloud or haze layer that blocks most observations, but a team led by Eliza Kempton at the University of Maryland compensated for this by watching the planet for a complete orbit. This revealed that the day side was 279°C, while the night wasjust 165°C – a disparity that is only possible if the atmosphere contains heavy molecules, such as water. “We think we detect water vapour, but it's challenging because water…

Our experts examine the hottest new research CUTTING EDGE In Douglas Adams's popular sci-fi series The Hitchhiker's Guide to the Galaxy, the wandering characters find their way to a mysterious world named Magrathea that was once at the centre of the custom planet-building industry. In the story, Magrathea is described as an ancient planet orbiting around twin suns in the heart of the Horsehead Nebula. But how common might such planets actually be in our Galaxy? Gabriele Columba, a PhD student in the department of physics and astronomy at the University of Padua, Italy, and his colleagues have been investigating. The type of planetary system they're interested in is an exoplanet orbiting a binary pair where both partners are white dwarfs – which they dub Magrathea worlds. (Although, here they're…

As a woman in the space sector, I take great pride in smoothing the path for leadership and innovation – although I find the lack of gender diversity within the industry still quite concerning. Despite an improvement in the number of women entering the space industry over the past 20 years, particularly at a senior level, it remains a male-dominated field. To this day, only 11 percent of all people that have been to space are women; and beyond that the representation of women in STEM, a vital talent pipeline for the sector, sits at only 22 per cent globally. Increased commercialisation and funding are paving the way to revolutionise our ability to journey deeper into space. Despite this momentum, the UN reports only one in five space industry workers…

The early Universe was a far busier place than it is today. Ten billion years ago, the rate at which stars burst into life and galaxies crashed together was 10 times higher. JWST aims to investigate the driving force behind this activity – as well as its sharp decline – by tracking galaxies over time to see how they have evolved. JWST is able to study areas previously hidden from view and begin to reveal how the formation of stars – some of the smallest objects in the Universe, cosmologically speaking – can influence the structure and evolution of some galaxies, some of the largest objects in the Universe. The Physics at High Angular resolution in Nearby Galaxies Survey (PHANGS) represents the largest survey of nearby galaxies in JWST's first…

JWST will also take a look a little closer to home at the planets within our own Solar System, and it has already turned its eyes on several of our planetary neighbours. As planets only shine by reflecting starlight, they do not emit much energy or visible light, yet they still radiate in infrared, making them ripe candidates for JWST. JWST's near- and mid-infrared sensitivity can look through the atmosphere to different depths, highlighting the evolution of cloud structures and storms in finer detail than ever before. Three specialised infrared filters on JWST's nearinfrared camera, NIRCam, turned their sights on Jupiter, the largest planet in our Solar System. Each filter is assigned a colour – red, yellow/green or blue – to allow astronomers to transpose the invisible infrared into something…

The Summer Triangel is one of the best-known asterisms in the night sky. Made out of three bright stars – Deneb. Vega and Altair – it's often among the first star patterns that newcomers to astronomy identify, because it's so obvious to the naked eye. More experienced observers love it because a host of celestial summer sights can be found inside and around it, all of which are visible to the naked eye or through binoculars. Wair until the darkest time of the balmy summer nights and look out for these 10 of the best… 1. North America Nebula To the left of Deneb you'll see, out of the corner of your dark-adapted eye, a large smudge around four times as wide as the Moon. Through a small telescope this…

Ophiuchius, the Serpent Bearer occupies a large piece of the sky. The 11th-largest constellation by area, its shape is like a box with a roof and legs. Sabik (Eta (η) Ophiuchi) is the star that marks the box's southeast corner (lower left as seen from the UK), where it connects with the eastern leg. In traditional depictions, Sabik marks the position near to one of Ophiuchus's knees. This is a mid-brightness star shining at mag. +2.4, easily visible to the naked eye. The name Sabik is Arabic for ‘the preceding one’ but why it has this name isn't completely clear. Sabik is a binary with two similarly bright, white components in a mutual 88year orbit. The stars’ brightness and spectral classifications are mag. +3.0, A2 and +3.5, A3. The orbit…

1. Antelope Island State Park 2. Arches National Park 3. Bryce Canyon National Park 4. Canyonlands National Park 5. Capitol Reef National Park 6. Cedar Breaks National Monument 7. Dead Horse Point State Park 8. Dinosaur National Monument 9. East Canyon State Park 10. Fremont Indian State Park 11. Goblin Valley State Park 12. Goosenecks State Park 13. Helper (town) 14. Hovenweep National Monument 15. Jordanelle State Park 16. Kodachrome Basin State Park 17. Natural Bridges National Monument 18. North Fork Park 19. Rainbow Bridge National Monument 20. Rockport State Park 21. Steinaker State Park 22. Timpanogos Cave National Monument 23. Torrey (town) 24. Zion National Park…

The Sun has been showing increased activity over recent months and with its position in the sky now optimal from the UK, this is a great time to review some of the techniques required to image it. Solar imaging isn't without risk, and concentration needs to be high at all times to avoid accidents. It goes without saying that you should never look directly at the Sun nor point any instrument at it without using appropriate filters. The two most common ways to view the Sun using a telescope are in white light or with a solar narrowband filter. Ready-made white-light filters are available or you can make your own (following instructions provided by the supplier). Narrowband filters are more expensive and can be either built into a dedicated solar…

VITAL STATS • Price £1,095 • Optics Air-spaced FPL-53 ED doublet • Aperture 102mm • Focal length 714mm, f/7 • Focuser 2-inch dual-speed rack and pinion • Extras Losmandy mounting bar, Vixen-style top accessories bar, aluminium flight case • Weight 5.8kg • Supplier Rother Valley Optics • Tel 01909 774521 • www.rothervalleyoptics. co.uk The Horizon 102 ED Doublet is the latest addition to the Rother Valley Optics (RVO) family of Horizon refractors, which includes the Horizon 60, 72 and 80 doublets. It offers both the largest aperture and longest focal length of the series at 714mm, giving a focal ratio off/7. We received the standard package (carry case and telescope with tube rings and bar), along with a suite of optional accessories to help with our test, including a finderscope,…

JULY HIGHLIGHTS Interview: Searching for Earth 2.0 Astronomer Chris Impey discusses exoplanets and the hunt for habitable worlds beyond our Solar System. Will an Asteroid Destroy Earth? In this episode of The Sky at Night, Maggie and Chris find out about asteroid detection and planetary defence. Observing forms and telescope software Download planetary observing forms and access software to help you with this month's Deep-Sky Tour (page 56). The Virtual Planetarium…

Comet 238P/Read spends its lifetime much closer to the Sun than most comets in the asteroid belt, yet has managed to hold on to its water, according to recent observations by the James Webb Space Telescope. “In the past, we've seen objects in the main belt with all the characteristics of comets, but only with this precise spectral data from Webb can we say yes, it's definitely water ice that is creating that effect,” says Michael Kelley from the University of Maryland, who led the study. But while 238P/Read's water might have survived the relative warmth of the asteroid belt, the same does not appear to be true for its carbon dioxide. The molecule usually makes up 10 per cent of similar comets, but JWST failed to find any on…

Violent disruption by a supermassive black hole may have triggered the blast A huge eruption in the distant Universe has now been identified as the brightest cosmic explosion ever witnessed. The event, AT2021lwx, was first discovered in 2020 by the Zwicky Transient Facility, but has continued for the last three years. It is so far away its light has been travelling for eight billion years and is two trillion times brighter than the Sun. The current leading theory for the cause of the outburst is that a cloud of gas or dust around 1,000 solar masses broke apart as it passed a supermassive black hole. As the fragments were swallowed, it created shockwaves that produced the intense glow. “With new facilities like the Vera Rubin Observatory coming online in the…

With a primary mirror measuring 6.6m across made from 18 gold-coated segments, the James Webb Space Telescope (JWST) is a beautiful instrument in its own right. But stunning as this technological marvel might be, it's nothing compared to the remarkable data it has unearthed over the last year. JWST launched on 25 December 2021, reaching its operational orbit at the second Lagrange point, 1.5 million kilometres from Earth, a month later. After a few more months calibrating its instruments, it was finally ready to turn its gaze on the Universe. JWST has been tasked with investigating four main science goals: the early Universe and the first galaxies; the growth and evolution of galaxies over time; the lifecycle of stars; and the study of other worlds. The new telescope is uniquely…

Stars begin their lives in dense clouds of obscuring dust and gas, but JWST's high-resolution infrared capabilities are able to pierce through this and reveal stars growing in their cosmic nurseries. One of the first images released by JWST back in July 2022 was of NGC 3372, a young star-forming region 7,600 lightyears away, in the northwest corner of the Carina Nebula, NGC 3372. JWST's infrared instruments revealed the edge of a gigantic gaseous cavity – a huge bubble created by the intense radiation and stellar winds from nearby massive, hot, young stars, dubbed the Cosmic Cliffs. As the ionised rim of the bubble pushes into the gas and dust of the nebula, the change in pressure can cause either a boom or bust – material either collapses to form…

CAUTION Use extreme caution when viewing Venus during the day, due to its close proximity to the Sun DON'T MISS Follow the crescent BEST TIME TO SEE: All month Venus has been dominant in the UK's evening sky for months, but during July its position after sunset rapidly deteriorates. Although a shame for naked-eye views, it's through the telescope that things are really starting to get interesting – the caveat is, you'll need to find it during the day. In a dark sky, Venus's brightness works against it through a telescope. Its intense glare is jostled by the unsteady seeing you get at low altitude after sunset (or before sunrise when it's in the morning sky). During the day, it gets higher and can be seen under steadier conditions. A…

1. Sadr, the Heart of Cygnus 10 x 50 The mag. +2.2 star Sadr (Gamma (γ) Cygni) is sometimes called ‘the heart of Cygnus’, but it is really only part of the story. If you look carefully, you'll notice that Sadr is merely the point of inflexion in a cardioid-shaped asterism of 11 mostly 6th-magnitude stars. It has a diameter of a little less than 2° and offers a wide variety of colours, from deep orange through yellow and white, to an intense blue-white. ☐ SEEN IT 2. NGC 6940 10 x 50 The open cluster NGC 6940 deserves to be far better known. Use the chart to identify mag. +4.0 41 Cygni and mag. +4.9 30 Vulpeculae and you'll find NGC 6940 between them, appearing like an oval patch…

The Sun had set by the time we pulled into a parking lot just outside Moab, Utah. This is where we agreed to meet our host for an evening under the sky and, sure enough, we arrive to find a convoy of four cars waiting for us. At the front was a large station wagon with decals on it that gave away the subject of this night-time expedition: “Have telescopes, will travel!” We followed the convoy along lonely roads before parking in La Sal Mountains Viewpoint in eastern Utah's canyonlands. The station wagon was already there. It belonged to our host, Alex Ludwig at RedRock Astronomy, who was already unloading collapsible chairs and parts of the mount for a 9.25-inch refractor. “Let's set up by this bush – it will…

While she may not currently be a household name, Roman will soon be much better-known, as an infrared telescope named in her honour is set to launch in 2027. The Nancy Grace Roman Space Telescope will have a 2.4m mirror – the same size as that of the Hubble Space Telescope – but its Wide Field Instrument will have a field of view 100 times that of Hubble's infrared camera. It will use this huge view to create a 3D map of galaxies, galaxy clusters and distant supernovae to measure how matter is distributed throughout the Universe. These observations will compliment those by ESA's upcoming Euclid mission (see page 66) in the quest to trace dark energy, the mysterious force that appears to be accelerating the expansion of the Universe.…

In 2022, my image of NGC 6888, the Crescent Nebula was shortlisted for the Astronomy Photographer of the Year competition. In this article I hope to give you an idea of how the image was created. The first step with any astrophoto is to collect the data. This stage is crucial because the quality of the starting data will determine how good the finished image is; 45 hours of very high-quality data was collected for this image. Once collected, I moved onto processing, and the first step here was image calibration and integration. These steps removed artefacts from the raw data and averaged together a large dataset to remove random noise from the final image. This was absolutely necessary because the signal in any single capture is very faint. We…

Its 102mm aperture – relatively large for a refractor – places the Horizon 102 ED firmly in the heavyweight range, ensuring that as much light as possible hits the camera sensor and granting astrophotographers access to fainter, more delicate objects. This glass, coupled with a focal length of 714mm, also means more detailed captures of popular Messier and NGC classics. The addition of the optional, specially designed 0.8x reducer/flattener provides a wider field of view should you wish to image larger objects. Meanwhile, the FPL-53 glass is designed to limit chromatic aberration (such as colour fringing and halos) over legacy FPL-51 glass. Rother Valley Optics bench-tests each OTA before delivery to ensure it meets the highest optical standards. A summary of this test is included with each Horizon 102 ED.…

What are quasars? We think there are supermassive black holes at the centre of every massive galaxy in the Universe. These black holes are accreting material from their near surroundings, usually gas or dust. In some cases, the powerful gravitational forces involved serve to heat up this material, resulting in intense radiation being emitted. We call these extreme objects active galactic nuclei, and quasars are the brightest and most powerful examples of them. What makes them such mysterious objects? Supermassive black holes are roughly the size of a solar system. This is very small relative to a full galaxy, which could contain hundreds of millions to trillions of stars. There's lots of gas in galaxies, but the mystery lies in how this can get down to the central black hole…

EYE ON THE SKY VICTORM BLANCO 4-METRE TELESCOPE, 18 MAY 2023 There'S A lot to unpack in this stunning image, which was captured recently by the Dark Energy Camera at NOIRLab's Cerro Tololo Inter-American Observatory in Chile, but the stars of the show – literally – are the two bright white dots left of centre. These are infant stars HR 5999 and HR 6000, formed around a million years ago. Yetto achieve the mass needed for nuclear fusion to start taking place, their heat and light is derived from gravity alone. That's enough, though, for them to light up the gas and dust in their vicinity thus creating reflection nebula Bernes 149 – the blue haze you see around them. It's also enough for stars and nebula alike to shine…

Astronomers have successfully detected radio emissions from a Type la supernova for the first time after decades of trying, thanks to e-MERLIN, a network of radio dishes across the UK operated from Jodrell Bank. A Type la supernova occurs when a white dwarf star is close enough to a stellar companion that it steals material from it. Eventually the dwarf reaches a critical mass and explodes in a supernova. Obtaining radio data of these explosions would be extremely useful in understanding the mass and geometry of material around them, but researchers hadn't been able to detect emissions at these wavelengths. That changed when the e-MERLIN team turned their array on SN0220eyj, first discovered on 7 March 2020. “The exquisite angular resolution of e-MERLIN, combined with its high sensitivity, enabled the…

Space is booming. Satellites monitor the climate, connect us to the internet and help us to study the Universe. Someday soon we could get back to the Moon. Spaceflight is getting cheaper as new commercial companies build rockets and spacecraft, while dangling the promise of space tourism. This is all very exciting, but at the same time, both scientists and industry workers are nervous about the potential dangers of uncontrolled proliferation. Streaks are increasingly spoiling astronomy images, while the threat of space advertising is rearing its head. The population of orbital debris could grow to pose unacceptable risks to spacecraft and leave space companies squabbling over real estate. The UK space industry's satellite-building capabilities – which cover all space applications from telecommunications to Earth observations to exploring the depths of…

Space for Everyone UK tour Various locations, June–September The UK Space Agency is on the road this summer, travelling the UK to promote the space sector and showcase how it can improve life on Earth. Space for Everyone: The Tour will see a 22-metre replica of the LauncherOne rocket make its way around the country, accompanied by industry experts seeking to inspire the next generation of astronauts and engineers. • Leicester: 29 June-3 July • Bradford: 6-10 July • Belfast: 20-24 July • Aberdeen: 3-7 August • Newcastle: 10-14 August • Hull: 17-21 August • Great Yarmouth: 24-28 August • Hastings: 31 August-4 September spaceperson.co.uk/rocket-tour…

One key part of JWST's mission will be to use its infrared eyes to peer through the dust and gas to the earliest eras of the Universe. Here it will help discover how the first stars and galaxies formed, as well as uncover fresh evidence for dark matter. JWST's Advanced Deep Extragalactic Survey (JADES) has been allocated a month of JWST's observing time, spread out over two years, and takes advantage of the telescope's unprecedented sensitivity to investigate the earliest galaxies in greater detail than ever before. In December 2022, JWST discovered the most distant, and therefore earliest, galaxies ever found – at least up to that point. The light from these galaxies set out when our Universe was just two per cent of its current age, and has taken…

We now know of thousands of planets beyond our Solar System, but while we may know the size, mass and orbit of these worlds, understanding of the atmospheres above them has proved elusive. Whether a ‘hot Jupiter’ or a small, rocky planet, knowing what is above the world gives key insights into their composition, formation and evolution. However, JWST's sensitive instruments can distinguish a far wider range of atmospheric molecules than ever before. In August 2022, JWST achieved a hat-trick of firsts when it made its first science observation of an exoplanet, where it also obtained the first detailed exoplanet spectrum in near-infrared and the first indisputable evidence for carbon dioxide in an exoplanet's atmosphere. The exoplanet in question was WASP-39b, a hot gas giant 700 lightyears away, discovered in…

A feature's position on the Sun's disc is given by a coordinate system similar to Earth's latitude and longitude, known as heliographic latitude and longitude. Programs like TiltingSun (atoptics.co.uk/tiltsun.htm) and WinJupos (jupos.org/gh/download. htm), can determine the correct values for your observations. It's easier to use an equatorial mount, although TiltingSun can also work for altaz setups. Assuming you have an imaging setup on an equatorial mount, before you start imaging, orient the camera so disc features pass horizontally across the field when slewing in right ascension (see step 1, below). Then worn out north, south, east and west (step 2). Using TiltingSun's graphic mode, enter the observation date and time (step 3). The program provides values for B0, L0, and P. B0 is the heliographic latitude of the central point…

PICK OF THE MONTH Jupiter Best time to see: 31 July Altitude: 30° Location: Aries Direction: East-southeast Features: Complex atmosphere, Galilean moons Recommended equipment: 75mm or larger Jupiter manages a decent altitude under dawn twilight by the end of July. Currently a morning planet, mag. -2.1 Jupiter appears 2.9° from a 29%-lit waning crescent Moon on the morning of 12 July, rising above the east-northeast horizon around 01:20 BST (00:20 UT). The planet has moved east from Pisces where it was last year and now sits in southern Aries. This is excellent news for the months ahead because as we approach opposition on 2 November 2023, Jupiter will be high in UK skies and visible in dark skies that last for a significant time. Although the skies certainly can't be…

The term minor planet describes an object in solar orbit which is neither a planet nor a comet, including asteroids. Pluto is neither an asteroid or a comet, although it was once a planet! It was relegated from main planet status in 2006 to become a dwarf planet. Historically, although ‘asteroid’ and ‘minor planet’ have been synonymous terms, definitions have become strained as new object discoveries and classifications have occurred. Still designated minor planet 134340, Pluto reaches opposition on 22 July and we're covering it this month despite its classification! During July, Pluto moves into a barren region of sky to the east of the Teapot asterism in Sagittarius. At an eye-wateringly faint mag. +14.4 and having a relatively low altitude from the UK, you'll need a decent-sized telescope to…

The first three-dimensional map of the Universe, made with a 1.5-metre telescope at Mount Hopkins in Arizona, was published over 40 years ago, in 1982. It took Marc Davis and his colleagues five years to determine the redshifts and corresponding distances of 2,400 galaxies, out to a distance of approximately 600 million lightyears. A second redshift survey of the same wedge of sky, carried out between 1985 and 1995, mapped the 3D positions of no fewer than 18,000 galaxies. Between 1997 and 2002, using multi-object spectroscopy at the 3.9-metre Anglo-Australian Telescope, a team led by Matthew Colless carried out the Two-DegreeField (2dF) Galaxy Redshift Survey. They determined the redshifts of 230,000 galaxies, out to a distance of some 2.5 billion lightyears. The Sloan Digital Sky Survey, which started in 2000…

The concept of lunar and planetary orbits can be difficult for beginners to grasp. This simple flat model will help you to introduce these ideas by showing that the Moon is in orbit around Earth, but the Earth-Moon system is also orbiting the Sun. The model is easy to make using just one sheet of A4 card, some paper fasteners and a dash of artistic flare. Although Earth and the Moon in our model are the correct sizes relative to each other, it goes without saying that the size of the Sun and the distances between the bodies are not to scale. If they were, our Sun would have a diameter of 10.9 metres, the distance between Earth and the Moon would be 2.76 metres and the distance between the…

PHOTO OF THE MONTH Solar eclipse Chirag Upreti, South Lefroy Bay, Western Australia, 20 April 2023 Chirag says: “The solar eclipse achieving totality was a fantastic experience – albeit it only lasted about one minute, and that was the fastest minute of my life! I was motivated to capture the transition from the diamond ring to Baily's beads and finally the surreal black Sun. Watching it occur in real time, it almost felt like the Moon was snapping into place as it blocked out the Sun.” Equipment: Sony a7R III mirrorless camera, Sony 200-600mm lens, Peak Design Travel Tripod Exposure: each image ISO 320 f/9.5, 1/2,000” Software: Photoshop Chirag's top tips: “For solar imaging or observing, make sure you're using solar filters from reputable suppliers, or eyeglasses that are ISO…