Indholdsfortegnelse for February 2024 i BBC Sky at Night

The latest astronomy and space news, written by Ezzy Pearson BULLETIN A planet-forming disc has been spotted around a star in another galaxy for the first time ever. The star, HH1177, is 160,000 lightyears away in the Large Magellanic Cloud, one of our own Galaxy’s satellites. It first came to astronomers’ attention when they observed the region with ESO’s Very Large Telescope in Chile. “We discovered a jet being launched from this young massive star,” says Anna McLeod from Durham University, who led the study. “Its presence is a signpost for ongoing disc accretion.” Such discs form from the gas and dust surrounding growing stars. As this matter can’t fall onto the star directly, it instead flattens out to form a rotating disc. Parts of the disc closer to the…

Water-rich, Earth-like planets could form in some of the most extreme stellar nurseries in the Galaxy, a new study has found. Our Sun is thought to have grown in a stellar nursery where several high-mass stars were also born. Massive stars emit a great amount of ultraviolet radiation that would push the gas and dust around in the planetary discs of nearby stars, potentially preventing rocky planets like ours from forming. Astronomers have been unable to investigate this further, however, as planetforming discs have so far only been found in regions where no massive stars are being born. Now, the James Webb Space Telescope has been able to uncover the first planetary disc, XUE-1, in such a region. “We found an abundance of water, carbon monoxide, carbon dioxide, hydrogen cyanide…

Rockets tearing through the ionosphere are creating aurora-like light shows which could begin affecting professional observatories. The light shows occur when the rockets burn their engines in the layer of ionised gas surrounding our planet, called the ionosphere. “The rocket exhaust reacts with the oxygen atoms in the atmosphere, causing them to emit deep red and bright blue colours,” says dark skies expert Stephen Hummel from the McDonald Observatory, Texas. This causes no permanent damage to the ionosphere but the glow can last for up to 10 minutes. Rockets have always created such holes, but in the last few years the number of launches has increased dramatically. Many of the recently observed aurorae are due to SpaceX’s Starlink launches. Not only are they numerous, but as the rockets conduct a…

Our experts examine the hottest new research CUTTING EDGE The Trojans are a population of asteroids caught within two of Jupiter’s Lagrange points – regions where the gravitational influence of the gas giant and the Sun, as well as the orbital centrifugal force, are all balanced. The L4 and L5 points are 60° ahead and behind Jupiter in its orbit, respectively. They act like gravitational traps and objects captured into them can be stable for the history of the Solar System. It’s thought that the objects making up the Trojans didn’t actually form near Jupiter’s orbit, but originated much further out in the Solar System. Somehow, they were transported inwards and captured. Spectroscopic observations show them to have the general appearance of dormant comets. But perhaps the most remarkable feature…

North York Moors and Yorkshire Dales Dark Skies Festival Various venues across both parks, 9–25 February Taking place at numerous locations in the North York Moors and Yorkshire Dales national parks, including Robin Hood’s Bay, Sutton Bank and Malham Tarn, this exciting celebration of all things astronomical returns for its ninth year on 9 February. New attractions for 2024 include a family-friendly constellation trail with activities for little ones, and a minibus tour of the Dales culminating in a stargazing session at Castle Bolton. With a packed schedule of star parties, astrophotography sessions, astronomyinspired arts and crafts, wildlife walks and more, this is one that northern amateur astronomers won’t want to miss. Prices vary. www.darkskiesnationalparks.org.uk…

With its clear skies and long, dark nights, winter is the perfect time to get acquainted with the constellations. Constellations – those areas of the sky named after mythological creatures, animals or objects – don’t need binoculars or a telescope to be seen. Their major stars are easy to make out just using your eyes from any reasonably dark site. As the year progresses, the constellations gradually shift their position in the sky. That’s because as Earth spins on its axis to give us day and night, it’s also orbiting around the Sun to give us the seasons. That orbit changes our view of the night sky as we look out at different parts of the Universe throughout the year. This guide will tell you the best constellations to look…

The first object widely accepted as a black hole is known as Cygnus X-1. As its name suggests, it’s an X-ray source in the constellation of Cygnus. X-rays don’t penetrate Earth’s atmosphere, so astronomers discovered it using a rocket launched to the edge of space in 1964. The system in question is home to a supergiant star known as HDE 226868. However, a star alone could not be producing the huge quantities of X-rays observed. More careful observations at the start of the 1970s revealed the influence of a hidden companion pulling the invisible puppet strings: a black hole. Not that the situation was immediately obvious. Cygnus X-1 was the subject of a bet between Kip Thorne, who argued for a black hole, and Stephen Hawking, who argued against it.…

Uranus Best time to see: 1 February, 18:50 UT Altitude: 54° Location: Aries Direction: South Features: Colour, atmospheric banding through larger scopes, moons Recommended equipment: 200mm scope or larger There’s no hiding the fact that the planets are struggling currently. The situation for all of the main planets is poor during the first half of 2024, with them either lost in the Sun’s glare or so low in the morning sky as to be unobservable. Don’t despair though, because their return in the last half of the year will be rather spectacular. The expanding evening twilight combined with Uranus’s daily westward drift catches up with this distant planet during February. Throughout the month it loses its ability to reach its highest altitude of 54° up when due south under truly…

The start of 2024 has a number of ‘bright comets’ visible, meaning a comet that is at least visible through a small scope or binoculars. 62P/Tsuchinshan, also known as Tsuchinshan 1, will be within the northern part of the Bowl of Virgo during February, situated fairly close to the mag. +4.9 star Rho (ρ) Virginis. You can find out more about 62P/Tsuchinshan’s position and visibility prospects on page 47. It’s now moving into galaxy territory, which will make it an excellent photographic subject. The comet was discovered at the Purple Mountain Observatory in Nanking, China in January 1965, having been identified on a photograph taken on New Year’s Day 1965. Subsequent observations made via the Mount Palomar Observatory, California in February 1965 allowed an initial orbital period of 7.22 years…

The Moon is a fascinating object to observe through a telescope. When the Sun is low, exaggerated shadows help reveal features that are all but invisible under direct illumination. A good example of this comes in the form of wrinkle ridges, the subject of this month’s challenge. Wrinkle ridges are typically found on the surface of a lunar sea. They form when basin-filling lava subsides under its own weight, causing buckling on the surface. Invisible under direct light, the ridges’ low height is exaggerated when the Sun is low in their sky. Most lunar seas contain them to a degree, something that makes hunting them down that bit easier. If you miss the right conditions for one sea, look at others as different ridges are likely to be seen as…

The many astronomical alignments at Chaco Canyon are a clue to the Ancestral Puebloan’s Sun-watching habits, but there is other evidence of ancient stargazing too. Just beyond Peñasco Blanco, one of the more remote great houses at Chaco, is a pictograph of a crescent Moon, a star and a human hand. It’s thought to represent what was visible on 5 July 1054, when a waning crescent Moon was located next to the supernova – exploding star – that is now the Crab Nebula, M1. It would have been visible in daylight for almost a month. Much easier to visit is the free-standing Rock of the Sun, with its petroglyph that’s thought to represent the Sun’s corona during a total solar eclipse visible from Chaco on 11 July 1097. It was…

In 1992, astronomers looked towards pulsar PSR B1257+12. The radio emissions of pulsars usually have such a regular beat they’ve been called cosmic clocks. But in this case, something was wrong. Every so often, the pulsar’s regular 6.22ms-long pulse would be ever so slightly off. After careful study, astronomers Aleksander Wolszczan and Dale Frail realised the irregularities had their own rhythm. The pattern was a perfect fit for what would happen if the pulsar’s precise timing was being upset by the gravitational pull of a pair of planets. It was the first strong evidence of the presence of exoplanets in orbit around another star. The discovery alone was a great achievement, but the real shock came when they worked out the size the planets would need to be to create…

Take the perfect astrophoto with our step-by-step guide Taurus is famous for two large, bright clusters. Arguably, the more compact and vibrant form of the Pleiades, M45, tends to steal the show, but the older, more dispersed form of the Hyades is impressive in its own right. Located adjacent to the bright-red giant Aldebaran (Alpha Tauri), the Hyades is easy to locate. This month, as well as being a beautiful and well-placed object for photographing on its own, there’s a bonus because comet 144P/Kushida will be traversing along the southern arm of the cluster’s sideways V-shaped pattern, towards and past Aldebaran. The Hyades is the closest true open cluster to the Sun, lying at a distance of 153 lightyears. Although it appears that Aldebaran is part of the cluster, it’s…

FEBRUARY HIGHLIGHTS Interview: analysing asteroid Bennu Prof Sara Russell is examining OSIRIS-REx’s returned sample to uncover the secrets of our Solar System. Download a lunar phases 2024 poster Keep up to date with Moon times and phases by downloading and printing our PDF poster covering all of 2024. Download planet observing forms Print out forms to help you keep track of your planetary observations and sketch what you see at the eyepiece. The Virtual planetarium Pete Lawrence and Paul Abel guide us through the best sights to see in the night sky this month.…

New observations from NASA’s Chandra X-ray Observatory have uncovered a nest of ‘spider pulsars’ hiding in the globular cluster Omega Centauri. Pulsars are neutron stars – the dense remnant of a dead star – that emit beams of radio waves. As they rotate, the waves sweep across the sky like a lighthouse beam, causing a pulsing pattern of radio emission. Spider pulsars are a unique variety, where another star orbits extremely closely, perhaps only 14 times the Earth–Moon distance away. At this proximity, energetic particles streaming away from the pulsar strip away the other star’s outer layers, slowly destroying the star. The collision between the stream of particles coming from the pulsar and that from the star creates a shockwave that glows bright in X-ray, which Chandra is able to…

As the needle touches down on a vinyl record, so has music itself touched down on other worlds beyond Earth. Whether the melodies have been transmitted from Earth’s surface or launched aboard spacecraft into space, it can be said that music has twinkled the stars. Radio signals have been leaving our planet for years, and even now, someone, somewhere, may be playing the PopMaster quiz on a distant world – and still getting it wrong. It’s a comforting thought to consider that vastly superior alien life may not be able to name that Number One hit from the 1980s. The crew of Apollo 10 managed to make their own ‘music’ in space. As the astronauts rounded the far side of the Moon in 1969, they reported whistling sounds to NASA…

According to Stephen Hawking’s theories, black holes won’t be around forever. Instead they will slowly evaporate as they give out what is known as Hawking radiation. Here’s what astronomers think might happen around the event horizon, the boundary between where you can outrun the black hole’s gravity and where you can’t. Quantum physics says that pairs of particles are constantly popping into and out of existence. Hawking’s genius was to imagine this process unfolding at the event horizon, so that the pair appear on opposite sides of it. One would be free to escape, but the other would be trapped forever. The escaping particles could combine into particles of light that stream out from the region just outside the event horizon. Over time, the black hole would slowly lose this…

Menkalinan (Beta (β) Aurigae) is the mag. +1.9 star that, along with Capella (Alpha (α) Aurigae), defines the northern edge of the misshapen pentagon of Auriga the Charioteer. The name translates from Arabic as the ‘shoulder of the rein holder’. Its location places it virtually on the solstitial colure, a great circle that passes through the positions of both summer and winter solstices as well as both celestial poles. It’s an eclipsing spectroscopic binary star, a system only detectable by the way high-resolution spectral lines appear to move in its spectrum. Both components are hot A-type stars, each with spectral types A1m IV, the ‘m’ indicating enhanced metals (elements heavier than helium) and the ‘IV’ indicating that they are sub-giants. Both components are nearly 50 times more luminous than our…

An International Dark Sky Park since 2013, the night sky above Chaco Canyon is almost as dark as the Ancestral Puebloans would have experienced it 800 years ago. The park’s Gallo Campground encourages the use of red lights at night and its bathroom block is dimly lit to preserve dark-adapted vision, making it a fine location for stargazing and astrophotography. However, just a mile up the road behind the visitor centre is a 25-inch Dobsonian telescope housed in an observatory dome. It’s open on Tuesday, Friday and Saturday evenings during summer. Sessions typically begin with a lecture on the astronomical practices of the Ancestral Puebloans.…

There are several ways of detecting exoplanets, but the vast majority are found using the transit method. Astronomers carefully monitor a star, looking for a brief, tell-tale dip in the star’s brightness as a planet passes across – or transits – briefly blocking out the starlight. The time between dips reveals how long the planet takes to orbit the star, and so how far out it is. The dip’s depth is determined by how much light the planet blocks, showing its physical size or radius. Once at least three dips have been found, it is considered a planetary candidate, but it still needs its mass measured to be a confirmed world. To do this, astronomers measure the effect the planet’s gravitational pull has on other objects in the system. If…

Expert processing tips to enhance your astrophotos To maximise the impact of deep-sky images, boosting the signal-to-noise ratio is key. In astrophotography, ‘signal’ is the light emitted from a deep-sky object – for example, a galaxy or nebula – while the ‘noise’ is produced by our camera’s internal systems. Because we use long exposures in astrophotography, our camera sensors start to warm up and introduce thermal and electronic noise into our images. This noise shows up as grainy artefacts that, as we start to stretch our data, can become noticeable and disruptive. While all cameras will produce noise to some extent, DSLRs are particularly susceptible, because they don’t have in-built cooling systems like dedicated deep-sky imaging cameras do. One way that astrophotographers combat noise is to take lots of images…

Our experts review the latest kit The centre-balanced equatorial mount has been around for a few years and has proven to be a popular and sturdy option for those looking for high load capabilities without the weight of traditional equatorial mounts. To this end, SkyWatcher has now launched its first foray into this type of equatorial mount, with the CQ350 Pro. Our first impression when the CQ350 Pro arrived was that clearly this is a sizeable mount – three large boxes were delivered. Opening the first, we found the mount head held firmly encased in thick foam, with a counterweight bar and accessories. The tripod, which weighs in at 15kg, was securely packaged in a separate box, and a pair of 10kg counterweights and an optional polar scope were enclosed…

Anita Chandran interviews Dr Ryan Campbell What do scientists mean by the Sun’s outer atmosphere? It’s easiest to understand from the inside out. The photosphere is the Sun’s visible surface. It corresponds to a point in the Sun’s atmosphere where visible light or ‘visible photons’ from the Sun’s core can escape. Photons are emitted from atoms in the Sun’s core and then re-absorbed by other atoms. This happens over and over again and the light can’t escape. After a long time, one of these trapped photons will escape from the Sun at the photosphere. As you get higher above the photosphere, first through the chromosphere and then to the corona, you expect things to get less hot and less dense. But something weird happens as you reach the corona. Instead…

EYE ON THE SKY JAMES WEBB SPACE TELESCOPE, 10 DECEMBER 2023 This new image of supernova remnant Cassiopeia A was captured by the Webb Telescope’s NIRCam (NearInfrared Camera) instrument. Although a little more muted in terms of colour than the MIRI (Mid-Infrared Instrument) image of the same object released in April 2023, the new shot reveals greater detail in Cas A’s interior. The orange and pink regions show the filaments of gas – sulphur, oxygen, argon and neon – left behind by the supernova explosion 340 years ago, while in the bottom-right of the image you can see a ‘light echo’. Now dubbed ‘Baby Cas A’ by the researchers, this is a region of dust some 170 lightyears further away that is now being illuminated by light from the long-past…

The ageing Hubble Space Telescope is back in operation after a problem with one of its gyroscopes took it offline for several weeks. Hubble has six gyros to help keep itself orientated, but only three are currently operational. On 19 November, one of the gyros gave abnormal readings, forcing the telescope into safe mode. NASA was able to return to operations quickly, only to enter safe mode twice more. On 23 November, the Hubble team paused operations to fully investigate the issue. After extensive testing, they determined the gyros would behave correctly if operated in high-precision mode during observations, and Hubble returned to operation on 8 December. Hubble has now been in orbit for 33 years. In the last few years, the telescope has suffered from several major technical problems,…

BULLETIN A rare system of six planets, all kept perfectly in balance, has been found around a star just 100 lightyears away. The star, HD110067, is so near to us that it’s the brightest-known system with four or more planets, making it an ideal candidate for further study. The system was first uncovered in 2020 by the Transiting Exoplanet Survey Satellite (TESS), which initially found just two planets. A second set of observations hinted there were actually four, but their orbits proved difficult to pin down. Intrigued by the unusual system, a team of astronomers used ESA’s Characterising Exoplanet Satellite (CHEOPS) to study the star, eventually confirming the presence of three planets. Unusually, these worlds were in what’s known as an orbital resonance. The closest planet to the star takes…

OPEN FOR ENTRIES! Supported by Liberty Specialty Markets Dates for your diary Competition opens: 4 January 2024 Entry closing date: 5 March 2024 Entrance fee: £10 for 10 entries How to enter and rules: Find out more by visiting the Astronomy Photographer of the Year website: apy.rmg.co.uk An exhibition of the winning images will be on show at the National Maritime Museum, London from 13 September 2024. It’s time to put the finishing touches to your best astro images if you want to be named the winner of the 2024 Astronomy Photographer of the Year competition, supported by Liberty Specialty Markets. With a grand prize of £10,000 on offer, the world’s biggest astrophotography competition is now open for entries. Each of the competition’s eight main categories covers a different astronomical subject –…

When you’re spotting the constellations, you’ll often see the Moon and maybe wonder why its appearance changes or why it doesn’t stay in the same area of the sky. Sometimes it’s a thin, silvery crescent low in the western sky, other times a bright and full disc high above us. As the Moon completes its orbit around Earth approximately every 27 days, its changing position causes the Sun to illuminate different regions of its surface, producing eight different shapes, or phases: new Moon, waxing crescent, first quarter, waxing gibbous, full Moon, waning gibbous, last quarter, waning crescent. The Moon closely follows the ecliptic, the Sun’s apparent path across the sky, which in simple terms is a great invisible circle around the Earth. Just as we see the Sun moving from…

Event horizon The radius around the singularity that forms the point of no return. Anything, even light, that falls within the event horizon will be trapped inside, hence the ‘black’ part of its moniker. Accretion disc A rotating disc of gas and dust caught in orbit around some black holes. It spins so quickly it can superheat, causing it to glow across the electromagnetic spectrum, including X-ray, optical, infrared and radio. Singularity The centre of the black hole, containing all the energy and matter that fall within it, collapsing to form a region of infinite density. The laws of physics as we know them break down in this region. Photon sphere Light emitted from the accretion disc is bent by the black hole’s gravity, forming a bright ring, known as…

BEST TIME TO SEE: First half of February in the evening sky Comet 144P/Kushida is a ninth-magnitude comet this month, a good target for a small telescope or larger-format binoculars. It’s especially well placed for Northern Hemisphere observation and is easy to locate for the first third of the month, as it passes across the Hyades open cluster in Taurus. On the night of 1/2 February, 144P/ Kushida is located 2.5° west of mag. +3.7 Gamma (γ) Tauri, the star at the pointed end of the ‘V’ shape formed by the main stars in the Hyades. The Hyades represents the face of Taurus the Bull, Gamma Tauri marking the position of the Bull’s nose. This position also places the comet just shy of 10° southeast of Alcyone (Eta (η) Tauri),…

1. The Hydra's Head 10 x 50 The one immortal head of the Hydra, the longest constellation, is defined by six stars, but only the faintest, mag. +4.4 Sigma (σ) Hydrae, retains a name – Minchir (the nostril) – that relates to Heracles’s nine-headed nemesis. Binoculars enable you to enjoy the wide variation in colours, from the intense white of mag. +4.3 Eta (η) Hydrae to the yellow-orange of mag. +3.1 Zeta (ζ), the brightest of the six. ◻ SEEN IT 2. The Missing Messier, M48 10 x 50 It was 12 years after Charles Messier incorrectly catalogued the position of M48 that Caroline Herschel rediscovered it, but it took over a century and a half for astronomers to realise she’d found the object that matched Messier’s description. Find this…

1. Mesa Verde National Park, Colorado Come for the Ancestral Puebloan cliff dwellings and stay for the night skies from 7,000 feet (2,130m) above sea level. Stay at Far View Lodge or Morefield Campground (book in advance at recreation.gov). www.nps.gov/meve 2. Hovenweep National Monument, Utah Hike to the ‘Sun daggers’, where concentric circle petroglyphs appear to mark the solstices, walk a canyon rim littered with Ancestral Puebloan buildings and stargaze from the 31-site campground ($20, open all year). www.nps.gov/hove 3. Natural Bridges National Monument, Utah The world’s first Dark Sky Park, offering all-night access to Owachomo, the smallest and thinnest of the three natural bridges and an iconic subject for astrophotographers. In summer, the Milky Way streams down to the horizon behind it. There’s a 13-site campground ($16, open all…

Although astronomers aren’t yet able to distinguish mini-Neptunes from water worlds, it doesn’t stop them theorising as to how the two types of planets came to be. “For a mini-Neptune-sized planet, several main pathways have been proposed,” explains Eliza Kempton. “It formed effectively dry, with not a lot of water vapour; [or] it has a rock and iron interior and it started with a hydrogenrich atmosphere, then over time, some of that hydrogen atmosphere – maybe a large fraction – was lost. “Then there’s the water world formation pathway, in which the planet initially formed farther away from its host star, where it was colder, and there was a lot of icy material. The planet incorporated a lot of icy material when it was born.” As planets grow, it often…

Practical astronomy know-how for every level of expertise Locating celestial objects through a telescope eyepiece can be surprisingly difficult. The magnification and relatively narrow field of view make it all too easy to miss your target as you move the telescope across the sky. However, a finderscope or a red dot finder can help enormously, as the first has a low magnification while the second has zero magnification, so both have a wide field of view. Optical finderscopes are essentially very small telescopes with a primary lens and an eyepiece with a crosshair to place over the object that you are seeking. We use them to simplify centring. A red dot finder, on the other hand, projects an apparent target or small red dot onto the night sky that you…

Your best photos submitted to the magazine this month PHOTO OF THE MONTH The Soul Nebula Jon Kelly, Tockwith, North Yorkshire, 10 December 2021, 19, 21 and 27 January 2022, 16–17 January 2023 Jon says: “The Soul Nebula is a visually stunning target and contains everything from starforming regions to Bok globules. I particularly like the myriad colours with subtle shades denoting the emission lines of the gases present. Processing this image was challenging due to some data being captured under a full Moon – I can’t waste a rare clear night, full Moon or not! But I am very happy with the end result.” Equipment: QHY600L camera, CFF Telescopes 135mm refractor, Sky-Watcher EQ6-R Pro mount Exposure: 23h of 10’ Software: PixInsight Jon’s top tips: “Planning and preparation are key.…

Our experts review the latest kit One of the conflicts of reviewing astronomy kit is to find something that you don’t want to have to return – like these binoculars. They arrived in a semi-rigid clamshell case, immediately conveying the idea that the manufacturer believes them worthy of enhanced protection. The rubberarmoured binoculars themselves had a light but robust feel, and the armour was especially grippy on the outside of the tubes. Also in the case were a neck strap, a tetherable rain-guard type of eyepiece cover, tetherable objective lens caps, a microfibre cloth and a protective pouch for the binoculars. The hinge was quite stiff, but moved smoothly without any stiction; once you set your interpupillary distance (the distance between the centres of the eyepieces) it is unlikely to…