Innholdsfortegnelse for January 2018 i Australian Sky & Telescope

Every 26 months, Earth and Mars come close to each other in space, offering a short window during which a voyage to the Red Planet is as efficient a trip as possible. Apart from 2009, engineers have used each such window this century to send spacecraft to Mars. The next, in 2018, will see NASA launch its Insight robotic lander, aiming to study the planet’s geological evolution. But 2020 will be special. Here on Earth, a conflation of technological progress, exploration strategies and delayed missions will mean that not one but four (or more) spacecraft will be rocketing to the Red Planet. Not only are the usual suspects NASA and ESA sending missions in 2020, but first-time voyagers are going, too. The United Arab Emirates’ Hope orbiter will join six…

SO THE RUMOURS WERE RIGHT after all. On August 17, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) registered tiny ripples in spacetime, produced by a pair of frantically orbiting neutron stars right before they collided. What’s more: telescopes on the ground and in space detected the fading glow of the radioactive fireball that resulted from the cosmic smash-up, all across the electromagnetic spectrum. “The detection of gravitational waves from a binary neutron star merger is something that we have spent decades preparing for,” notes astrophysicist Alan Weinstein (Caltech). “All of our dreams came true.” According to his colleague Barry Barish (also Caltech), one of LIGO’s founding fathers and co-recipient of the 2017 Nobel Prize in Physics, the new discovery “establishes gravitational-wave science as a new emerging field.” Vicky Kalogera (Northwestern…

When we look into the constellation of Canis Major — past nearby Sirius and out into the star fields of the Milky Way’s Perseus Arm — we’re looking rimward, away from the galactic centre. This field is rich with young, open star clusters, and bright and dark nebulae. At a distance of around 3,500 light-years we find the remains of a collapsing molecular cloud rich in silicates, iron and carbon, infalling onto a protostar of around three solar masses. This protostar is Z Canis Majoris. Typical of these young objects (called FU Orionis variables, or FUORS), it has an accretion disk with polar jets. But infrared observations reveal that there is more to this system than meets the eye. Only one hundred astronomical units (a.u.) from the Z CMa primary…

On the evening of Wednesday, January 31, the first of two total lunar eclipses for 2018 will grace the skies above us. Totality will be seen across eastern Asia and the eastern Pacific. China, Mongolia, Japan, Korea, Russia, the Philippines and most of Indonesia will see the eclipse in its entirety. From New Zealand and the east coast of Australia the event will be visible from start to finish, with the eclipse beginning in darkness from New Zealand and not long after the end of astronomical twilight from the eastern states of Australia. Perth will miss the opening minutes of the event, but this is no big deal as the subtle shadow in the early stages of a total eclipse isn’t visible to the naked eye. The map and diagram…

No one had thought about actively involving landowners from the very start. WOULD YOU SELL your property to scientists who plan to build the world’s largest array of radio telescopes? As a reader of Australian Sky & Telescope, you possibly might. But farmers in the sparsely populated Great Karoo region in South Africa are not so keen. Most of them are very suspicious of the plans for the Square Kilometre Array. Radio galaxies, pulsars and the epoch of reionisation don’t ring a bell with them. Instead, they believe that the SKA antennas will compromise their mobile phone reception. Or, worse, that the mysterious radio waves might cause cancer. Local opposition to the future observatory is fierce — and growing. Gone are the days when an astronomer would do his research…

THE LONG-AWAITED James Webb Space Telescope (JWST) — successor to the Hubble Space Telescope — will now launch between March and June 2019. Integrating and testing various spacecraft elements, including the five-layered sunshield, is taking longer than expected and has forced a roughly 6-month launch delay from the original October 2018. The project will nevertheless remain within the budget that NASA agreed to in 2011. The telescope and its science instruments are currently undergoing extensive testing. The final step will be to integrate the telescope onto the spacecraft and test the fully assembled observatory before it is launched to orbit the Sun at the L2 Lagrangian point, 1.5 million km from Earth.…

RESEARCHERS HAVE found strong evidence of titanium oxide (TiO) in the atmosphere of hot Jupiter WASP-19b — a Jupiter-mass planet with a surface temperature of 2000K that orbits its host star in only 19 hours. Just as ozone absorbs solar radiation in Earth’s atmosphere, producing an inversion layer within which temperature increases with altitude, titanium oxide may play the same role in the exotic atmospheres of hot Jupiters. But while many astronomers suspect TiO’s presence, actually detecting this molecule has proven difficult. As WASP-19b transited across the face of its star, Elyar Sedaghati (European Southern Observatory) and colleagues employed ESO’s Very Large Telescope (VLT) to capture the star’s light as it passed through a sliver of the planet’s atmosphere, which absorbs certain wavelengths depending on its chemical makeup. Analysing the…

Camille M. Carlisle Illustration by Terri Dubé The spacecraft launching in 2020 build on more than a half century of exploration, much of it unsuccessful. A revamped, strategic approach by NASA fostered a string of achievements since 2000. • Learn more at https://is.gd/ marscrafthistory. Success or Failure? So far, humans have launched 42 missions to the Red Planet. Of those, 43% have failed, 38% succeeded and 19% were partial successes. The low success rate has led scientists to joke about the ‘Martian ghoul’. Flight Plan 2020 To minimise propellant, Mars-bound spacecraft take the most efficient path from Earth to Mars. Sitting on the launch pad, the spacecraft already orbits the Sun (with Earth). After it launches, it boosts itself out of an Earthlike orbit into a more elliptical one, with…

I spent a few years fanatically working my way through observing lists. But these days I’m just as likely to head out with no firm plan or destination, and just see what the sky serves up. I don’t see as many different things, but I discover more. I was on a ramble through the Milky Way last summer when I stumbled on a rich concentration of stars on the boundary between Orion, the Hunter, and Taurus, the Bull. Even low-power binoculars will show about two dozen stars in a fat crescent spanning 4° from north to south. From the centre of the crescent, a chain of 5th- and 6th-magnitude stars runs off to the east-southeast. I can’t help but see a stingray, swimming westward above Orion’s head. It turns out…

On October 2 last year, Aren Heinze of the University of Hawaii Asteroid Terrestrial-impact Last Alert System (ATLAS), discovered an 18.2-magnitude comet sporting a coma approximately 7 arseconds in diameter and a tail about 10 arcseconds long. The comet was found in images secured with the 0.5-m f/2 Schmidt telescope at Mauna Loa. Orbital computations revealed the new object to be moving in an almost parabolic orbit toward perihelion on February 21, 2018 at a rather small 0.58 astronomical units (a.u.) from the Sun. On its way to perihelion, C/2017 T1 (Heinze) will pass just over 0.2 a.u. from Earth on January 4. Although the comet favours northern latitudes at the time of closest approach, it should be visible during late December and during the first few days of January…

For anyone who witnesses totality, the feeling of a deep bond is unavoidable, and certain truths become apparent in our guts. LIKE MANY ASTRONOMY enthusiasts, I long ago caught the total solar eclipse bug, and I’ve joined eclipse expeditions to other countries to stand in the shadow, in awe, with my fellow converts. In addition to the always sublime totality, this offers an excuse for going new places, following curves inscribed on the globe by a cosmic airbrush, and meeting other devotees along the way. Totality has always been hard to explain to those who’ve never experienced it. Which is why it’s always exciting to see friends and relatives, not to mention vast multitudes of deserving strangers, finally getting the chance to see what all the fuss is about. One…

IT WASN’T THAT LONG AGO when you could count the major manufacturers of stand-alone telescope mounts on the fingers of one hand, and ‘advanced electronics’ meant a clock drive powered by a synchronous AC motor. Not so now. Today there’s a huge selection of mounts from dozens of manufacturers in North America, Europe and Asia. They range from tiny trackers made for cameras to behemoths designed for observatory installations and the largest amateur telescopes. And even many of the ‘simplest’ mounts feature motor drives with computerised Go To pointing. This is all good news, since a solid mount with Go To drives and smooth tracking goes a long way toward making a night under the stars a pleasant experience. I suspect that the new CGX mount from Celestron has caught…

FIFTY YEARS AFTER IT BECAME the fourth country to launch a satellite from its own soil, Australia will finally get its own national space agency. The announcement was made at the International Astronautical Congress in Adelaide in September. An Expert Reference Group, appointed to review Australia’s space industry capability, is considering the best ways in which to establish the agency and define its role. “The global space industry is growing rapidly and it’s crucial that Australia is part of this growth,” said the Acting Minister for Industry, Innovation and Science, Senator Michaelia Cash. “A national space agency will ensure we have a strategic long-term plan that supports the development and application of space technologies and grows our domestic space industry. The agency will be the anchor for our domestic coordination…

Volans, the flying fish, is one of the far-southern constellations invented by Bayer for his Uranometria of 1603. Starting in the west of the constellation, we find the show-piece stellar pair Gamma Volantis , or DUN 42 . One of James Dunlop’s discoveries, the bright, unequal and well-separated stars are a beautiful combination, and a fine object through any telescope. Hartung called the colours golden and pale yellow. Zeta Vol ( DUN 57 ) to the south-east is a wide, easy pair, another of Dunlop’s doubles found during his 1820s survey of the southern sky from his backyard at Parramatta. DUN 57 is a bright orange star with a fainter, well-separated companion, magnitudes 4 and 9. The field has some fairly bright stars. A nice object, it is accessible to…

JANUARY 7 This morning, Jupiter and Mars appear less than 1/3° apart in the eastern sky before dawn. Jupiter is 20 times brighter than Mars. JANUARY 13–14 Mercury and Saturn are close together, low in the eastern pre-dawn twilight. JANUARY 31 Total eclipse of the Moon during the evening for Australia and New Zealand. See page 54. FEBRUARY 15 Partial eclipse of the Sun, visible only from Tasmania and far southern Victoria and South Australia. For Melbourne, the event will begin at 1:05pm Eastern Standard Time (adjust for daylight saving), with mid-eclipse at 1:22pm. MARCH 20 Equinox: The hours of darkness and daylight are roughly equal today for most temperate latitudes. MARCH 20 Take a look at Mars tonight with your binoculars or telescope, and you’ll see it bracketed by…

ASTRONOMY 2018 YEARBOOK Wallace, Dawes & Northfield For more than a quarter of a century, the Astronomy yearbook series has been an essential companion for every self-respecting Australasian astronomer. Packed full of data, with extensive month-by-month detail of what’s visible in the night sky (planets, constellations, meteor showers, comets, minor planets and more), it will keep you going all year. Available in October. Pre-order yours now! $29.95 plus postage & handling 2018 AUSTRALASIAN SKY GUIDE Nick Lomb An ideal yearbook for beginners, the easy-to-read 2018 Australasian Sky Guide provides a month-by-month guide to what can be seen with the naked eye, along with lots of interesting facts and figures, detailed descriptions of special astronomical events, and planetary data. Available in November. Pre-order yours now! $16.95 plus postage & handling ASTRONOMY…

IN THE LAST ISSUE I WROTE about amateur telescope making in the 1950s. This month let’s look at what’s possible in the hobby today. I could scarcely believe it when Detlef Werner Schmidt wrote to me about his latest project. Some of you may already know Werner as the designer of the Feather Touch focuser and the founder of Starlight Instruments, so you might expect another fabulously well-machined gem, and you would be right. But would you expect an imaging Newtonian that can be switched from f/4 to f/8 in about 10 minutes? Without re-collimating? No kidding. Werner has built just such a telescope. And he has built it with his typical attention to detail and exquisite machining. Werner had several goals in mind when he started. He wanted a…