Indholdsfortegnelse for November 2020 i BBC Sky at Night

Chemical linked to life found on Venus The clouds above the planet contain phosphine, which is produced by bacteria on Earth Could life be hiding in the clouds above Venus? Possibly, according to astronomers who announced on 14 September that they’d found a rare molecule, phosphine, present in the atmosphere of our neighbouring planet. “The reason for the excitement is that phosphine gas on Earth is made by microorganisms that live in oxygen -free environments,” says Jane Greaves from Cardiff University, who led the observations to track down the molecule. “There is a chance that we have detected some kind of living organisms in the clouds of Venus.” Greaves first tracked down the molecule in 2017 using the JCMT (James Clerk Maxwell Telescope) in Hawaii, before reconfirming the discovery with…

Comet aurora Ultraviolet aurora have been seen dancing around comet 67P/Churyumov- Gerasimenko - the first time such a light show has been seen around a celestial object other than a planet or moon. Recently analysed images taken by the Rosetta spacecraft show the solar wind interacting with the comet’s coma to produce the aurora. Dark skies in NI The Dark Sky Observatory and Visitor Centre in the Davagh Forest, Mid Ulster is finally due to open on 17 October, after being delayed due to the COVID-19 pandemic. The forest is Northern Ireland’s first accredited International Dark Sky Park. A Pi-fect planet A ‘pi-planet’ has been discovered zipping around its host star once every 3.14 days. The planet has a radius about 0.95 times the size of Earth’s, but it isn’t…

A cosmic coincidence continues Since ancient times, comets have been seen as a sign of impending disaster. During a global pandemic, did Comet NEOWISE keep up with the tradition? As long as there have been people to worry about what the future might hold, humanity has looked anxiously to the skies for signs and omens as some sort of indication about what might lie ahead. Given the confidence and complacency which our scientific knowledge has bestowed, it is hard for us today to appreciate the very real fear and serious consideration that was accorded to the most transient of unusual natural phenomena. Even relatively rare meteorological happenings, such as a lunar halo appearing with the chance placement of a planet in it, gave rise to such sayings as, “If the…

PICK OF THE MONTH Uranus Best time to see: 1 November, 23:50 UT Altitude: 51° Location: Aries Direction: South Features: Small greenish disc, brighter moons Recommended equipment: 150mm or larger Uranus was at opposition on 31 October and remains well placed for UK viewing throughout November and December. While opposition marks a big change in the appearance of a close planet like Mars, for the distant ice giants Uranus and Neptune, the difference is small. Easily seen though binoculars, the tricky aspect of identifying Uranus currently comes from its location in southern Aries where there aren’t many stars to signpost it. One way to locate its general area is to identify Menkar (Alpha (a) Ceti) and Sheratan (Beta (β) Arietis); Uranus lies 60 per cent of the way along this…

The asteroid 8 Flora is at opposition on 1 November, when it will appear at mag. +8.0 in the constellation of Cetus, the Whale. At the start of the month it’s conveniently located just to the west of the mag. +3.5 star, Kaffalijidhma (Gamma (y) Ceti). At 00:00 UT on 1 November the asteroid is just 20 arcminutes west of this star. Kaffalijidhma marks the southern point of Cetus’s misshapen pentagonal head. Over the remainder of the month, Flora tracks west, arcing slightly to the west-northwest towards the end of November. It never strays too far from the head asterism though. Flora is a large and bright object, with a mean diameter of 128km based on tri-axial ellipsoidal dimensions of 136km x 136km x 113km. It has a relatively high…

It’s often stated that the planet Uranus is visible to the naked eye. However, if you ask someone whether they have actually seen it unaided, the answer you’ll normally receive is no. The reason for this is that this distant planet shines at the edge of naked-eye visibility and any direct views of it aren’t always conclusive. Most of us live under less than perfect skies. An average dark sky will have a limiting magnitude - that’s the faintest star you can see - somewhere between mag. +5.0 and mag. +5.5. Country locations may push this further, perhaps down to mag. +6.0 or even mag. +6.5 from really dark locations. In addition, the limiting magnitude will vary with altitude on the sky. Although you might be able to see a…

A gorilla Ok, there isn’t really a gorilla on the ISS, but there is a gorilla suit sent up in 2016 by astronaut Mark Kelly, as a birthday present for his twin brother Scott. He used it to prank Tim Peake (above). Pizza Hut In 2001, Pizza Hut sent specially made pies to the ISS, after cosmonaut Yuri Usachov mentioned he had a craving. Bagpipes... In 2015, astronaut Kjell Lindgren played ‘Amazing Grace’ on a set of bagpipes in tribute to a colleague who had passed away. ...And other musical instruments Over the years there has been quite an ensemble, including a guitar, flute, piccolo, keyboard, alto saxophone, koto and a didgeridoo. An espresso machine In 2015, astronauts got a chance to brew a real cup of coffee from an…

Want to get to space? Here’s how… Ordinary people can leave Earth’s atmosphere today, but are the prices sky high? Go back 60 years and the idea of anyone going into space was little more than a dream. Today, more than 550 people have achieved this ambition, journeying beyond our planet and into low Earth orbit. For decades, it’s been governments footing the bill for training and flying astronauts, but that could all be about to change. After years of development, private spaceflight is on the verge of being able to regularly carry private passengers, allowing anyone who wants to travel to the stars to do so - provided they have the money, that is. The company closest to sending people into space is SpaceX. In fact, it has already…

Catch Neptune and its largest moon, Triton A careful balance of settings is required to capture the Solar System’s outermost planet Neptune is a tricky target for astrophotography: being such a distant planet it appears small and dim from Earth. To be fair, as it typically hovers at mag. +7.8 it’s only dim compared to its Solar System neighbours. For imaging the brighter planets, it’s normal to use a high frame rate camera configured for short exposures. By capturing frames at a rate of tens (or sometimes hundreds) every second, it’s possible to take advantage of the short periods when distortions caused by our atmosphere are at a minimum. These frames are then extracted, aligned and averaged for a decent result. The lower brightness of Neptune means a bit of…

The Altair Starwave 110ED-R refractor is a welcome update to Altair’s established product range, the ‘R’ indicating an upgraded rack and pinion focuser with additional features for an improved experience. Indeed, the improved construction and finish stays true to the reputation of Starwave’s telescopes, with smoothly machined fittings and flat silver trimmings, complemented by a luxurious, metallic white paint job. The solid look and feel of the tube assembly has been achieved with the reduction of excessive weight in mind; we were pleasantly surprised about how manageable the telescope was to lift from its aluminium padded case. It was also reassuring to discover - after lugging weighty refractors around over the years – that the 6.8kg Starwave 110ED-R represents an ideal compromise between aperture and portability, offering a large enough…

Nisha Beerjeraz-Hoyle interviews Samantha Cristoforetti What side effects do you experience living on the ISS? In space your body experiences a lot of changes, although you’re not aware of them all. About half of astronauts suffer from something called space adaptation syndrome, which is similar to being seasick and is caused by the disconnect between what you perceive and what your vestibular system is telling your brain. Luckily, I didn’t feel sick but I did experience a pressure in my head for about a week. This is brought on by the redistribution of bodily fluids towards the upper body and makes you feel congested; some astronauts feel like they have a cold for their entire stay. How did your body cope returning to Earth after 200 days in space? Space…

NOVEMBER HIGHLIGHTS Interview: 20 years of the ISS Veteran NASA astronaut Jeff Williams discusses the history and future of the International Space Station. Life on Venus? A Sky at Night special The team get exclusive access to UK astronomers who have made a huge discovery in the search for life beyond Earth. Audiobook: Diary of an Apprentice Astronaut Listen to chapters from Samantha Cristoforetti’s new book, revealing the story behind her 200 days on the ISS. The Virtual Planetarium Pete Lawrence and Paul Abel guide us through the best sights to see in the night sky this month.…

Phosphine absorbs light at a very specific wavelength that is unique to the chemical. Because of this, Greaves’s team were able to hunt for phosphine by looking at how bright the planet was at a range of wavelengths around this value. At first, they did this using the relatively low resolution JCMT (shown in yellow) before re-observing Venus with the more precise ALMA (shown in red). Both telescopes found a dip in brightness created by something in the atmosphere absorbing light at a specific wavelength, one that perfectly corresponded to the wavelength phosphine absorbs at. They had made a positive detection.…

Exoplanets dancing around double stars What weird and wonderful orbits might be possible around binary stars? Although the vast majority of extrasolar planets discovered so far are around singleton suns, many of the stars in our Galaxy are part of binary or multiple systems. It’s much trickier to detect exoplanets in multiple systems (for example, the other bound stars completely swamp any sign of a companion planet), but there’s no reason to suppose that they’re not also pretty common. There are three different kinds of orbit that a planet in a binary star system can remain stable within. The first is a ‘satellite-type’ or S-type internal orbit, whereby the planet circles one of the two stars. Astronomers have discovered around 50 confirmed exoplanets on S-type orbits, and in fact, we…

Beyond Venus Following the news about possible signs of microbial life in the clouds of Venus, the team report on the discovery from the Royal Observatory Greenwich. Chris and Maggie find out about further research and look into the wider search for life in the Solar System, focusing on Mars, Titan, Enceladus and Europa, as well as biological signatures on planets orbiting distant stars. BBC Four, 8 November, 10pm (first repeat BBC Four, 12 November, 7:30pm) Check www.bbc.co.uk/skyatnight for more up-to-date information…

ONLINE TALKS Royal Observatory shows Hosted over Zoom by astro experts, ‘Solar System Discovery’ (above) takes an interactive, fact-filled tour of the Solar System, while ‘Space Queries and Theories’ are short talks after which you can ask space-related questions. Suitable for ages 7+. www.rmg.co.uk/whats-on Deep Astronomy This long-running YouTube channel tackles tons of heavyweight astronomical subjects and features discussions with a range of expert guests. www.youtube.com/user/tdarnell/featured RADIO Astro Radio Featuring astronomy chat, science news and eclectic music throughout the week, Astro Radio is available via several music streaming services, such as tunein.com. DOCUMENTARIES A Year in Space This 12-part documentary follows veteran astronaut Scott Kelly’s year-long mission aboard the ISS with cosmonaut Mikhail Kornienko, testing the effects of living long-term in zero-g on the human body. www.netflix.com Horizon Take a…

KEY TO STAR CHARTS When to use this chart 1 November at 00:00 UT 15 November at 23:00 UT 30 November at 22:00 UT 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 November* Moonrise in November* *Times correct for the centre of the UK Lunar phases in November MORE ONLINE Paul and Pete’s night-sky highlights Southern Hemisphere sky guide…

Alrescha (Alpha (α) Piscium) is the primary star of the faint constellation of Pisces. At mag. +3.8 it’s easy to spot with the naked eye under reasonable skies. It lies at a distance of 151 lightyears from the Sun and is a close binary star with an apparent separation between components of just 1.8 arcseconds. Alpha Piscium A is a white star with the spectral type A0p and is mag. +4.3. Alpha Piscium B is also white, being of spectral type A3m and mag. +5.2. The ‘p’ in Alpha Piscium A’s spectral type indicates it has an unspecified peculiarity in its spectrum, which often means it shows an unusual abundance of metals (where ‘metal’ refers to elements heavier than hydrogen). Indeed, the ‘m’ in Alpha Piscium B’s spectral type indicates…

1 NGC 1499 This month we look at objects scattered around the pattern of stars depicting Perseus’s western foot. Lodged in his shin is th emission nebula NGC 1499, also known as the California Nebula because it’s outline resembles the US State. NGC 1499 has an integrated magnitude of +5.0, but as it’s spread over a 145 x 40 arcminute area, its surface brightness is quite low, making it a challenge to see visually. It’s located between Menkib (Xi (ξ)) and Zeta (ζ) Persei and has been seen in 7x50 binoculars. It best suits a low power view; hydrogen-beta filters can bring out the nebula, revealing it as a gentle glow elevated in brightness against the background sky. □ SEEN IT. 2 NGC 1342 Using the imaginary line between Epsilon…

27,600 Orbital speed in kilometres per hour 420 Weight in tonnes 4 billion Maintenance cost in US dollars per year 24 Number of individuals who have visited 16 Frequency of Earth orbits in 24 hours 109 Length in metres, end-to-end 4 Minimum time in hours for a spacecraft to arrive after launch 2,700 Individual science investigations 350,000 Number of sensors monitoring crew health and safety 1,500,000 Lines of flight computer code 388 Cubic metres of habitable space 73 Wingspan in metres of the solar arrays 231 Spacewalks since launch, including during construction…

Your log book is a great way of keeping track of all the seasonal changes you’ve observed on Mars. It should be a bound notebook, and for each observation you need to record the date, the time (in UT), the telescope and magnifications used, alongside any drawings you make of Mars. The process of making a Mars drawing is straightforward. To begin, make a ‘Mars blank’ – this is a circle, 50mm in diameter, drawn on a sheet of paper you can take out to the telescope to start your drawing. At the telescope, first spend some time looking at Mars to see what features are present. Then, when you are ready, use a 3B pencil to draw in the terminator on your ‘Mars blank’ along with the main dark…

ZWO has become a well-established brand in the CMOS camera marketplace; over the last decade it has produced models for all types of imaging. We are used to seeing the cylindrical shape and red colour of its deep-sky cameras, but now ZWO has launched two new ‘GT’ models that break with tradition. Here, we take a look at the ASI 1600GT M, a mono camera with a built-in filter wheel. After opening the 1600GT M’s box, we were presented with a square-shaped camera; it’s quite a bit larger than a normal ZWO model – with a stylish heatsink back case, two cooling fans and two handles – and finished in anodised red. On the bottom we found a USB 3.0 and two USB 2.0 sockets, plus a ‘power in’ socket…

The objective lens of the Starwave is a 110mm, f/7 doublet, with a fluorophosphate, low-index glass element, known as FPL-51 ED. This lens arrangement allows reasonable control of the various colours (or wavelengths) of visible light, bringing them to focus together for a sharper, more pleasing eyepiece view and reducing chromatic aberration when compared to an achromatic lens. Altair Astro informs us that each scope is guaranteed to arrive with properly collimated, or aligned, lenses. The lens cell comes with a matching star test image produced from a double-pass autocollimator. We tested this for ourselves - as the finely tuned collimation of a refractor is essential for viewing close double stars and sharper planet features – and were reassured to see several craterlets within the lunar crater Plato. Doublet refractors…

HUBBLE SPACE TELESCOPE, 14 SEPTEMBER 2020 This beautiful face-on spiral galaxy is NGC 2835, found 35 million lightyears away near the head of the constellation of Hydra, the Water Snake. Stretching up to 65,000 lightyears across, more than half the width of the Milky Way, its four distinct arms and one less-defined southern arm teem with sparkling blue clouds. It’s within these many pockets of cold, dense gas that clusters of hot, new stars are born. The cold gas is also fuelling the spiral’s supermassive black hole, up to 10 million times more massive than our Sun, at the centre of this galaxy. NGC 2835 is one of over 100,000 star-forming regions and gas clouds outside our Milky Way that are being catalogued for PHANGS-HST project. This unique combined Hubble…

Have you imagined where you’d be when you hear that aliens have turned up? I heard about the amazing discovery featured in this month’s programme while sitting in my kitchen, speaking to an old friend of the programme, Chris North, on the phone. Chris was calling to tell me that a team led by his colleague Jane Greaves in Cardiff had found what they thought was a biosignature - a sign of life - in the atmosphere of Venus. What he actually said to me was, “Can you speak Venusian?” It’s the title of one of Patrick Moore’s books covering ‘independent thought’ - UFOs, a vicar who thinks the Sun is cold, that sort of thing. It quickly became clear that, unlike the man who in one archive episode explained…

National Astronomy Week 14-22 November 2020 Although National Astronomy Week (NAW) 2020 has had to move online, it’s still a great chance to focus on and celebrate the star of the show: Mars. Having just passed its best opposition for years, the Red Planet will be a high and bright feature of early evening skies from mid-November - perfect for some family observing time. NAW organisers plan to live-stream views through amateur and professional telescopes, and provide live expert commentary. There will also be daily sessions aimed at young people organised by science outreach organisations, plus online talks by astronomical societies. With interest in the planet already high thanks to the flurry of Mars missions launched this year, it’s a great time to get young observers involved. Whatever equipment you…

Star clusters make great training targets if you’re new to deep-sky imaging, and November certainly isn’t short of bright ones to choose from. Messier 39 in Cygnus is a perfect example. It’s home to a decent number of reasonably bright stars, sits high above the horizon in the early evening this month and is large enough on the sky that it looks impressive in images captured with introductory level deep-sky imaging equipment. Equipment The cluster spans about 40-arcminutes, and it will look nicely placed against the background stars in the field of view of a DSLR attached to scopes with focal lengths as short as around 400mm. Then you just need a motorised mount to track the sky during long exposures. It’s worth investing in a Bahtinov mask for the…

Mare Serenitatis is one of the primary dark lava seas on the Earth-facing side of the Moon. The ‘Sea of Serenity’ makes a good pair with neighbouring 700km Mare Tranquillitatis, the ‘Sea of Tranquillity’. Serenitatis is roughly circular and sits between Mare Imbrium to the west and Mare Tranquillitatis to the southeast. Less well defined to the southwest is Mare Vaporum. To the northeast Serenitatis overspills into an irregular region north of 96km Posidonius, a crater which appears to have an inner floor tilted up in the east. South of Posidonius is the dark, circular but broken form of 61km Le Monnier, resembling a less impressive version of the 400km x 260km Sinus Iridum, the ‘Bay of Rainbows’, located on the northwest shore of 1,250 km Mare Imbrium. Le Monnier…

1. The Queen’s Aeroplane The golden yellow 4 Cassiopeiae marks the starboard wingtip of a little aeroplane-shaped asterism made of eight stars that shine at mag. +8.0 or brighter. The other wingtip, a degree to the west, is the mag. +6.6 blue-white V649 Cas. The curved ‘fuselage’ extends to a mag. +6.7 orange-red star, nearly a degree to the north. A dark transparent sky will enable you to appreciate the variety of colours in this star party favourite. □ SEEN IT 2. M52 We’ll swap to larger binoculars to get the best of M52, which lies in the same field of view as our first target. You should see about 10 stars resolved against a wedge-shaped grainy glow about 0.25° long. This glow is the light of 1,000 stars that…

1 Starboard Solar Arrays 2 S6 Truss 3 S5 Truss 4 Solar Arrays 5 S3/S4 Truss 6 ExPRESS Logistics Carrier (ELC) 2 7 External Stowage Platform (ESP) 3 8 ELC 4 9 S1 Truss 10 AMS Experiment 11 Zvezda Service Module 12 Docking Compartment (DC 1) 13 Poisk Research Module 14 Zarya Control Module 15 Rassvet Research Module 16 Pressurised Mating Adaptor (PMA 1) 17 Canadarm2 18 S0 Truss 19 Quest Airlock 20 Z1 Truss 21 ESP 2 22 Unity (Node 1) 23 Bigelow Expandable Activity 24 Thermal Control Radiators 25 Solar Arrays 26 P1 Truss 27 ELC 3 28 ELC 1 29 P3/P4 Truss 30 P5 Truss 31 Port Solar Arrays 32 P6 Truss 33 Destiny Laboratory 34 Tranquility (Node 3) 35 Permanent MultiPurpose Module 36 Cupola 37 ESP…

Turn an unused camera lens into a guidescope Improve the accuracy of your mount by repurposing an old lens from a camera A guidescope is an important item that helps with autoguiding in astrophotography; it’s needed to correct the small errors that can occur when you are tracking with a motorised mount that has mechanical gears. An example is the unwanted image trailing that can occur – even though your mount has a good alignment – when you are taking very long exposures of an object on your main camera. The guidescope and guide camera, along with suitable software, will help to counter this by checking the position of selected stars and communicating with the mount. Importantly, the guidescope makes small corrections to keep your scope stable and fixed on…

PHOTO OF THE MONTH The Moon occulting Mars Ricardo J Vaz Tolentino, Belo Horizonte, Brazil, 6 September 2020 Ricardo says: “Despite the adverse conditions - atmospheric turbulence, dew, wind and cold - I managed to capture this beautiful and anxiously awaited astronomical event from my rooftop observatory in Belo Horizonte. The image was taken at 03:02 UT, at the start of the occultation, and is one of an hour-long sequence of photos. By 03:04 UT, Mars had disappeared from view, reappearing 50 minutes later in the southeastern region near the lunar crater Helmholtz.” Equipment: Orion StarShoot Solar System Color Imaging IV camera, Sky-Watcher Skyliner-400P FlexTube Dobsonian, Celestron Ultima 2x Barlow Exposure: single exposure Software: PhotoImpression Ricardo’s top tips: “To capture the Moon occulting planets, focus ahead of time on the…

Integral to the ZWO ASI 1600GT is the Panasonic MN34230 senor, which has a proven track record for capturing stunning astro images since it was released a few years back. In the early days it suffered from amp glow and other small issues, but ZWO has done some good work to iron out these problems and make its versions of the sensor very clean, with the result that there is little noise (unwanted artefacts) in the final images. The sensor is more commonly known as the ASI 1600 and has a lot to offer in terms of its specifications, starting with a resolution of 4,656 x 3,520 pixels and a pixel size of 3.8μm. There are plenty of custom sizes that can be selected for the camera’s region of interest…