Sommaire pour March 2024 de Astronomy

FOLLOW THE BRIGHT LIGHT A 200-second-long gamma-ray burst (GRB) detected March 7, 2023, and designated GRB 230307A was over a million times more luminous than our entire galaxy. JWST follow-up observations suggest the GRB resulted from a collision of neutron stars 1 million light-years distant. DISK MATTERS The first extragalactic circumstellar disk around a forming star was found located in the Large Magellanic Cloud about 160,000 light-years away. After a jet from the star hinted at the disk’s presence, the researchers used data from the Atacama Large Millimeter/submillimeter Array to confirm. REMEMBERING SPACE TRAVELERS Ken Mattingly, who orbited the Moon on Apollo 16, died Oct. 31, 2023. One week later, Frank Borman, who commanded Apollo 8, died Nov. 7. Shortly after on Nov. 27, the 10th female astronaut in space,…

Piercing the Pleiades IT’S ANOTHER QUIET MONTH for meteors, with no major showers. However, keep an eye on the sky for the random fireball. March is a peak time to view the zodiacal light in the evening sky. The steeply inclined ecliptic, rising from Pisces though Aries and into Taurus, is where this cone-shaped glow can appear as twilight diminishes. It is fainter than the Milky Way. Try using averted vision by scanning your eyes back and forth along the western sky to render the zodiacal light visible. You need a very dark western horizon with no city lights in that direction, and higher altitude aids viewing this ethereal glow. Avoid the Moon as well. The first two weeks of March are best, followed by the last few days after the…

EXPECT A NICE binocular comet — but hope and plan for the hyped-up eruption. Comet 12P/Pons-Brooks floats about 15° high in the west when the sky is fully dark some 90 minutes after sunset. That’s also the direction to travel to keep the most city skyglow behind you. Moonlight interferes after midmonth, but keep watching. Picturesque wide-field viewing and imaging occurs when the crescent Moon joins Jupiter from the 12th to the 14th. Perhaps shoot a little earlier — say, 75 minutes after sunset — to catch some dim orange skyglow at the horizon and deep blue above. If we get a super-long ion tail, the blue streak could cross in front of the Andromeda Galaxy on the 8th and 9th. To see horns and gaps in the inner coma,…

My still new-ish husband and I sat on our car in a quiet country cemetery on an August night in the early 2000s, watching the Perseids. I knew that my father would be sitting on his deck at his house in another town an hour away watching too, so we called him. “Hey Dad,” I said when he answered. “You watching?” “Yup,” he said. I suppose an aging cemetery isn’t a popular place to hang ona summer night, but it was the best place to see the Perseids and we had it to ourselves. We stayed for an hour with my dad on the phone, watching the meteors draw in the sky like acelestial Etch A Sketch. Every now and then, one would be brighter or longer or seem bigger…

BY MOLLY WAKELING Molly is an avid astrophotographer active in STEM outreach. She is pursuing her Ph.D. in nuclear engineering. In 1781, French astronomer Charles Messier published a catalog of 103 objects in the heavens. He was primarily interested in comets, but kept finding fuzzy smudges that did not move against the background stars — so he published a list of objects to avoid while comet hunting. The list includes diffuse nebulae, planetary nebulae, open clusters, globular clusters, and galaxies visible from Europe. With some additions by other astronomers, gleaned from Messier’s notebook margins, the list now has 109 objects (or 110, depending on who’s counting). It’s a familiar companion for observers, especially at this time of year, when amateurs across the Northern Hemisphere gear up for a Messier marathon:…

Lying 90 million light-years away in Aquarius, the peculiar galaxy NGC 7727 is the product of an ongoing galactic merger, captured with the Gemini South Telescope in Chile. The result is a mixture of active star-forming regions and molecular clouds, twining the galaxy’s features into what looks like a hazy ball of cotton candy. But NGC 7727’s most remarkable feature lies at its center: not one, but two supermassive black holes, the closest such pair to Earth yet discovered. The more massive of the two weighs in at 154 million times the mass of the Sun, while the other is 6.3 million solar masses. Though the pair is currently 1,600 light-years apart, the black holes are expected to merge within the next 250 million years. $150,000 The amount that the…

Visible to the naked eye  Visible with binoculars Visible with a telescope The evening sky of springtime hosts Mercury, Jupiter, and Uranus. It’s a good last chance to catch the richness of the jovian atmosphere, plus a few interesting events involving the Galilean moons. Venus dominates the morning sky, visible in brightening twilight, while Mars and Saturn progressively come into view late in the month. And if we’re lucky, Comet 12P/Pons-Brooks might put on a good show for binoculars as it crosses Andromeda, Pisces, and Aries. Mercury reaches its best evening appearance for the year as it extends its elongation from the Sun out to 19° by March 24. However, it is brighter before this date — catching it in mid-March at magnitude –1.5 on the 9th is likely one…

MILD SPRING EVENINGS are the best. 4 Vesta slides from the tip of Taurus’ horn, Zeta (ζ) Tauri, to the splashy but thin star cluster NGC 2129 at the feet of Gemini. Though a half-magnitude fainter than last month, Vesta still shines at about 8th magnitude, brighter than the rich but faint star cloud in this arm of our Milky Way Galaxy. Vesta is pretty easy in the smallest of scopes from the suburbs. On the 16th, you can slide 4° south of the First Quarter Moon to land on it. It only takes five dots of a pencil on paper and a couple of clear nights between the 13th and 16th, 21st and 23rd, or 29th and 31st to pick out the main-belt asteroid by its displacement. Next month…

THE CAMBRIDGE DICTIONARY defines magnificent as “deserving to be admired.” I had no trouble doing that when I walked into the offices of Stellarvue to get an extension ring for my SVX140T and to visit my friend and Stellarvue owner Vic Maris: While there, I witnessed an SVX180T 180mm f/7 refractor being prepared for shipment to some lucky customer. Until that moment, I had been happy with my Stellarvue 140mm f/6.7, but the power of 180mm dwarfed it by comparison. Completely captivated, I put a deposit down on a 180mm and waited — these hand-crafted instruments can take months to assemble. Fortunately, Stellarvue was in full production and just four months later I got the long-awaited call saying “Your scope is ready, come pick it up!” THE TIME HAS FINALLY…

Attention, manufacturers: To submit a product for this page, email products@astronomy.com. Coma free Meade Instruments Watsonville, CA Meade’s 8-inch f/10 LX200 ACF Telescope is a deep-sky rig equipped with the AutoStar II computer system. This go-to system not only contains over 145,000 targets, but also offers many options for telescope operation. The LX200’s signature is its Advanced Coma Free (ACF) optics, which flatten the field of view for even the largest eyepieces. Options for tripods and wedges are also available. $3,999.99 customerservice@meade.com www.meade.com Rocketing through history Penguin Random House New York City, NY In Dark Star: A New History of the Space Shuttle, Harvard University aerospace historian Matthew Hersch details NASA’s Space Shuttle Program and its many highs and lows, including the Challenger disaster in 1986. Hersch illustrates the shortfalls…

A WILD PILEUP IN WESTERN VIRGO American astronomer Halton Arp had an eye for the unusual. He studied galaxies with strange shapes in the hope they would lead to understanding galactic evolution. His 1966 Atlas of Peculiar Galaxies serves as a grand resource for studying interacting galaxies. This Hubble Space Telescope image shows Arp 248, a trio of island universes also known as Wild’s Triplet. Here we see the nearly face-on spirals PGC 36723 (lower right) and PGC 36733 (upper left); the third member lies off the top edge of this field. The trio lies some 200 million light-years from Earth. The smaller edge-on spiral between the two larger galaxies is an unrelated background object.…

EVERYTHING YOU NEED TO KNOW ABOUT THE UNIVERSE THIS MONTH NASA’s James Webb Space Telescope (JWST) strikes again, this time by capturing never-before-seen details in the dense core of the Milky Way Galaxy. The image shows Sagittarius C (Sgr C), a star-forming region located 26,000 light-years from us and 300 light-years from the Galaxy’s supermassive black hole, Sagittarius A*. JWST’s incredible level of resolution and sensitivity provides stunning features, both explained and unexplained. This colorful section of Sgr C contains a mosaic of around 500,000 shining stars spread across the frame. The azure emission and “needles” that appear to be pointing in every direction comprise a large-scale region of ionized hydrogen (HII) gas. Extending down from the top of the frame is an infrared-dark cloud, a dense region of cold…

SANDSTORMS JWST observations of exoplanet WASP-107 b reveal that the gas giant has an analogue to Earth’s water cycle based on silicates, the main component of sand. The silicates evaporate with trace amounts of water deep in its atmosphere, rise and form sand clouds, then rain drops of sand. CROSSED WIRES OSIRIS-REx’s drogue parachute failed as the mission reentered Earth’s atmosphere Sept. 24 with its precious sample of asteroid 101955 Bennu. NASA said Dec. 5 that loose usage of the word main in the craft’s blueprints led engineers to mistakenly connect two “main” wires that caused the drogue’s cord to be cut before it was deployed. Luckily, the main chute ensured a safe landing. TIT FOR TAT In an emerging inter-Korean space race, North Korea successfully launched a spy satellite…

BY STEPHEN JAMES O’MEARA Stephen is a globetrotting observer who is always looking for the next great celestial event. Any reference will tell you the Novaya Zemlya effect is a polar mirage — and it is. But Novaya Zemlya-like effects are not limited to the Arctic. The Novaya Zemlya effect is an atmospheric refraction phenomenon that causes a viewer to perceive the premature birth of the Sun as the long polar nights near an end. On Jan. 24, 1597, Gerrit de Veer, a member of Willem Barentsz’s icebound third arctic expedition, became the first known person to record the phenomenon; the Novaya Zemlya effect is named after the archipelago in north-western Russia where he witnessed it. On that day, two other crew members also glimpsed the Sun two weeks before…

RIDING HIGH in the southwest during spring evenings, our sister Luna is bright and white. On the evening of the 16th, at First Quarter, soak in the breathtaking series of seas in the north, then scan southward across the craters lining the day-night terminator. Anchored in the southernmost third of the lunar disk is the large crater Maurolycus, spanning some 70 miles and named after an Italian mathematician who disagreed with Copernicus’ Sun-centered solar system. The impact that carved out this classic beauty occurred on a thin enough spot to fracture the floor, which later allowed lava to seep up but not quite cover the complex of central peaks with a smooth skin. The event half-wiped out a crater to its immediate south as well as one to the northwest.…

Once I made the decision to add Starizona’s Microtouch focus motor to the rig, next came the challenge to attach it. The heavily geared telescope motor fastens directly to the focus shaft, eliminating any chance of focus backlash — unlike less powerful motors that attach through the 10:1 reduction gearing. After installing the focus motor, I ran the easy-to-use temperature compensation “learning feature” (included in motor’s software), which calculates the focus shift in relation to temperature drop. The focus motor continually keeps the image in focus by adjusting every 0.18-degree-Fahrenheit (0.1 degree Celsius) drop in temperature. Using the motor allows me to run my rig all night without having to refocus, and stars maintain the exact sharpness from the first image of the evening to the final image, even with…

Q | ON THE COLOR-WAVELENGTH SPECTRUM, GREEN FALLS BETWEEN YELLOW AND BLUE. WHY ARE THERE NO GREEN STARS? Jeff Franklin Surprise, Arizona A | This is an excellent question! It seems weird, right? The color of stars, or anything that gets really hot, is connected to its temperature. This is because hot objects emit light, which is called thermal radiation. The color of this light — or in physical terms, its frequency — depends on the temperature. As any object gets hotter, it emits more and more of its light at higher frequencies. The same way it takes you more energy to jump at a faster rate, it takes more energy to emit light at higher frequencies. These higher frequencies appear blue to our eyes, while lower frequencies appear red.…

Jupiter has now disappeared from the evening sky and Venus no longer graces the morning twilight. Sadly, this means we have only three naked-eye planets to follow this month, and all appear in the hours before sunrise. Saturn is the first of this trio to rise, and it also is the farthest from Earth. At the beginning of May, the ringed planet clears the eastern horizon more than four hours before the Sun. From mid southern latitudes, it climbs some 30° high by the beginning of astronomical twilight. The planet shines at magnitude 1.0 and moves slowly eastward against the backdrop of eastern Aquarius the Water-bearer. The planet’s high altitude delivers marvelous observing opportunities for those with telescopes. The great views come despite the rings being far less conspicuous than…