Check out the night sky this month, February 2024. Here are videos and articles highlighting the top sights to observe.
** What’s Up: February 2024 Skywatching Tips from NASA – NASA JPL
What are some skywatching highlights in February 2024? Venus begins its exit from the morning sky, as Mars makes its comeback. Plus, now through May is a good time to observe spiral galaxy M81.
Additional information about topics covered in this episode of What’s Up, along with still images from the video, and the video transcript, are available at https://science.nasa.gov/skywatch….
In February, the Winter Triangle is your guide to the night sky: The northern hemisphere is treated to views of the stars Procyon, Sirius, and Betelgeuse. Keep watching for the awe-inspiring space-based views of the Orion Nebula, which is sculpted by the stellar winds of central bright stars.
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“Tonight’s Sky” is a monthly video of constellations you can observe in the night sky. The series is produced by the Space Telescope Science Institute, home of science operations for the Hubble Space Telescope, in partnership with NASA’s Universe of Learning. This is a recurring show, and you can find more episodes—and other astronomy videos—at https://hubblesite.org/resource-galle….
Pete Lawrence and Paul Abel reveal what to see in the night sky tonight and throughout February, including the best comets, clair-obscure effects on the Moon, Orion, Gemini and star clusters.
00:00 Intro 00:13 Mercury, Venus and Mars 02:23 Jupiter and Saturn 03:41 Uranus and Neptune 06:22 Comets 11:25 Einstein Crater 13:34 Lunar X and V, Jewelled Handle 15:31 Orion 16:30 Castor and Pollux 17:50 M35 19:05 Ursa Major 20:15 Leo and the Sickle 22:00 Beehive Cluster 23:06 M67 25:08 Hydra
** Sky & Telescope’s Sky Tour Podcast – February | The Winter Hexagon and Constellations Near Orion – Sky & Telescope Youtube
Our monthly Sky Tour #astronomy #podcast provides an informative and entertaining 10-minute guided tour of the nighttime sky. Listen to the February episode and keep tabs on the Moon, say goodbye to a couple of planets, trace out the Winter Hexagon; and explore some lesser-known constellations near Orion. So bundle up, grab your curiosity, and come along on this month’s Sky Tour.
This artist’s impression is based on the aftermath of a supernova explosion as seen by two teams of astronomers with both ESO’s Very Large Telescope (VLT) and ESO’s New Technology Telescope (NTT). The supernova observed, SN 2022jli, occurred when a massive star died in a fiery explosion, leaving behind a compact object — a neutron star or a black hole. This dying star, however, had a companion which was able to survive this violent event. The periodic interactions between the compact object and its companion left periodic signals in the data, which revealed that the supernova explosion had indeed resulted in a compact object.
Astronomers have found a direct link between the explosive deaths of massive stars and the formation of the most compact and enigmatic objects in the Universe — black holes and neutron stars. With the help of the European Southern Observatory’s Very Large Telescope (ESO’s VLT) and ESO’s New Technology Telescope (NTT), two teams were able to observe the aftermath of a supernova explosion in a nearby galaxy, finding evidence for the mysterious compact object it left behind.
When massive stars reach the end of their lives, they collapse under their own gravity so rapidly that a violent explosion known as a supernova ensues. Astronomers believe that, after all the excitement of the explosion, what is left is the ultra-dense core, or compact remnant, of the star. Depending on how massive the star is, the compact remnant will be either a neutron star — an object so dense that a teaspoon of its material would weigh around a trillion kilograms here on Earth — or a black hole — an object from which nothing, not even light, can escape.
Astronomers have found many clues hinting at this chain of events in the past, such as finding a neutron star within the Crab Nebula, the gas cloud left behind when a star exploded nearly a thousand years ago. But they had never before seen this process happen in real time, meaning that direct evidence of a supernova leaving behind a compact remnant has remained elusive.
In our work, we establish such a direct link
says Ping Chen, a researcher at the Weizmann Institute of Science, Israel, and lead author of a study published today in Nature and presented at the 243rd American Astronomical Society meeting in New Orleans, USA.
The researchers’ lucky break came in May 2022, when South African amateur astronomer Berto Monard discovered the supernova SN 2022jli in the spiral arm of the nearby galaxy NGC 157, located 75 million light-years away. Two separate teams turned their attention to the aftermath of this explosion and found it to have a unique behaviour.
This artist’s impression shows the process by which a massive star within a binary system becomes a supernova. This series of events occurred in the supernova SN 2022jli, and was revealed to researchers through observations with ESO’s Very Large Telescope (VLT) and New Technology Telescope (NTT). After a massive star exploded as a supernova, it left behind a compact object — a neutron star or a black hole. The companion star survived the explosion, but its atmosphere became puffier as a result. The compact object and its companion star continued to orbit one another, with the compact object regularly stealing matter from the other’s puffy atmosphere. This accretion of matter was seen in the researchers’ data as regular fluctuations of brightness, as well as periodic movements of hydrogen gas.
After the explosion, the brightness of most supernovae simply fades away with time; astronomers see a smooth, gradual decline in the explosion’s ‘light curve’. But SN 2022jli’s behaviour is very peculiar: as the overall brightness declines, it doesn’t do so smoothly, but instead oscillates up and down every 12 days or so.
In SN 2022jli’s data we see a repeating sequence of brightening and fading
says Thomas Moore, a doctoral student at Queen’s University Belfast, Northern Ireland, who led a study of the supernova published late last year in the Astrophysical Journal. Moore noted in his paper.
This is the first time that repeated periodic oscillations, over many cycles, have been detected in a supernova light curve
Both the Moore and Chen teams believe that the presence of more than one star in the SN 2022jli system could explain this behaviour. In fact, it’s not unusual for massive stars to be in orbit with a companion star in what is known as a binary system, and the star that caused SN 2022jli was no exception. What is remarkable about this system, however, is that the companion star appears to have survived the violent death of its partner and the two objects, the compact remnant and the companion, likely kept orbiting each other.
The data collected by the Moore team, which included observations with ESO’s NTT in Chile’s Atacama Desert, did not allow them to pin down exactly how the interaction between the two objects caused the highs and lows in the light curve. But the Chen team had additional observations. They found the same regular fluctuations in the system’s visible brightness that the Moore team had detected, and they also spotted periodic movements of hydrogen gas and bursts of gamma rays in the system. Their observations were made possible thanks to a fleet of instruments on the ground and in space, including X-shooter on ESO’s VLT, also located in Chile.
Putting all the clues together, the two teams generally agree that when the companion star interacted with the material thrown out during the supernova explosion, its hydrogen-rich atmosphere became puffier than usual. Then, as the compact object left behind after the explosion zipped through the companion’s atmosphere on its orbit, it would steal hydrogen gas, forming a hot disc of matter around itself. This periodic stealing of matter, or accretion, released lots of energy that was picked up as regular changes of brightness in the observations.
Even though the teams could not observe light coming from the compact object itself, they concluded that this energetic stealing can only be due to an unseen neutron star, or possibly a black hole, attracting matter from the companion star’s puffy atmosphere.
Our research is like solving a puzzle by gathering all possible evidence,” Chen says. “All these pieces lining up lead to the truth.”
With the presence of a black hole or neutron star confirmed, there is still plenty to unravel about this enigmatic system, including the exact nature of the compact object or what end could await this binary system. Next-generation telescopes such as ESO’s Extremely Large Telescope, scheduled to begin operation later this decade, will help with this, allowing astronomers to reveal unprecedented details of this unique system.
Check out the night sky this month, January 2024. Here are videos highlighting the top sights to observe.
** What’s Up: January 2024 Skywatching Tips from NASA – NASA JPL
What are some skywatching highlights in January 2024? The year kicks off with the Quadrantid meteors, and some great Moon-planet pairings. Plus, did you know the stars shift in the sky by four minutes each day?
Additional information about topics covered in this episode of What’s Up, along with still images from the video, and the video transcript, are available at https://solarsystem.nasa.gov/skywatch….
In January, the northern hemisphere features beautiful views of Capella, a pair of giant yellow stars; Aldebaran, a red giant star; and two star clusters—the Hyades and the Pleiades. Keep watching for the awe-inspiring space-based views of the Crab Nebula, the remains of a star that exploded as a supernova.
Pete Lawrence and Paul Abel reveal the top things to see in the night sky this month, including the planets of the Solar System, clair obscur effects on the Moon, Comet 144P/Kushia and Orion.
** Sky & Telescope’s Sky Tour Podcast – January | The Quadrantid Meteor Shower and Spotting Planets – Sky & Telescope Youtube
Our monthly Sky Tour #astronomy #podcast provides an informative and entertaining 10-minute guided tour of the nighttime sky. Listen to the January episode and watch one of the year’s better #meteor showers, then take up the challenge of spotting five #planets; size up a celestial queen with an ego problem; and learn about a celestial hunter who, uh, also has an ego problem. So bundle up, grab your curiosity, and come along on this month’s Sky Tour.
*** 2024 Unmissable Night Sky Events! – Alyn Wallace
00:00 2023 00:34 Aurora Boost 01:30 January 02:40 February 02:53 March 03:40 April 06:01 May 06:35 June 07:12 July 07:25 August 07:57 September 08:25 October 10:22 December
Check out the night sky this month, December 2023. Here are videos highlighting the top sights to observe.
** What’s Up: December 2023 Skywatching Tips from NASA – NASA JPL
What are some skywatching highlights in December 2023? Clear skies will make for ideal viewing of the Geminid meteor shower, and grab your binoculars to search for asteroid Vesta.
0:00 Intro 0:14 Moon & planet highlights 0:59 Geminid meteors peak 2:05 Observing asteroid Vesta 4:08 December Moon phases
Additional information about topics covered in this episode of What’s Up, along with still images from the video, and the video transcript, are available at https://solarsystem.nasa.gov/skywatch….
Step outside on a cold December night when the stars shine bright to find the Big Dipper, Cassiopeia, and Cepheus. They will help you locate a binary star system, a fan-shaped open star cluster, and a variable star. Stay tuned for space-based views of a ragged spiral galaxy, an open star cluster, and an edge-on galaxy.
** Geminids, Venus, Jupiter, Orion, Comet Tsuchinshan | Night sky December 2023 – BBC Sky at Night Magazine
Find out what’s in the night sky tonight, December 2023, with astronomers Pete Lawrence and Paul Abel as your guide. Venus and Jupiter are bright, the Geminid meteor shower reaches its peak and asteroid Vesta reaches opposition. Comet 62P/Tsuchinshan increases in brightness and Orion returns with its wealth of deep-sky wonders.
00:00 – Intro 00:14 – Mercury 00:55 – Venus 02:33 – Jupiter 03:02 – Saturn 03:44 – Uranus and Neptune 05:39 – Mare Orientale 06:58 – Jupiter occults Ganymede 07:55 – Geminid meteor shower 10:02 – Vesta at opposition 10:31 – Comet 62P/Tsuchinshan 15:22 – Orion and deep-sky objects 22:16 – Taurus 23:36 – Auriga and open clusters 25:00 – Camelopardalis 26:36 Kemble’s Cascade
** Sky & Telescope’s Sky Tour Podcast – December | The Geminid Meteor Shower and Bright Evening Stars –Sky & Telescope Youtube
Our monthly Sky Tour #astronomy #podcast provides an informative and entertaining 10-minute guided tour of the nighttime sky. Listen to the December episode and keep tabs on the #Moon’s whereabouts, watch for some impressive #shootingstars, track down four #planets, and gaze at a tall tower of bright evening #stars. So bundle up, grab your curiosity, and come along on this month’s Sky Tour.
Listen and subscribe to this podcast at https://skyandtelescope.org/observing/ and don’t forget to subscribe to S&T’s YouTube channel to get alerts about new videos, including this monthly podcast
Watch the #Geminid #meteorshower on the evening of December 13th and the morning of December 14th with tips from Sky & Telescope! The #geminids are one of the top #meteor showers of the year. Learn about what the Geminids are and how they form.
This artist’s impression shows the HH 1177 system, which is located in the Large Magellanic Cloud, a neighbouring galaxy of our own. The young and massive stellar object glowing in the centre is collecting matter from a dusty disc while also expelling matter in powerful jets. Using the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, a team of astronomers managed to find evidence for the presence of this disc by observing its rotation. This is the first time a disc around a young star — the type of disc identical to those forming planets in our own galaxy — has been discovered in another galaxy.
In a remarkable discovery, astronomers have found a disc around a young star in the Large Magellanic Cloud, a galaxy neighbouring ours. It’s the first time such a disc, identical to those forming planets in our own Milky Way, has ever been found outside our galaxy. The new observations reveal a massive young star, growing and accreting matter from its surroundings and forming a rotating disc. The detection was made using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, in which the European Southern Observatory (ESO) is a partner.
“When I first saw evidence for a rotating structure in the ALMA data I could not believe that we had detected the first extragalactic accretion disc, it was a special moment,”
says Anna McLeod, an associate professor at Durham University in the UK and lead author of the study published today in Nature.
“We know discs are vital to forming stars and planets in our galaxy, and here, for the first time, we’re seeing direct evidence for this in another galaxy.”
This study follows up observations with the Multi Unit Spectroscopic Explorer (MUSE) instrument on ESO’s Very Large Telescope (VLT), which spotted a jet from a forming star — the system was named HH 1177 — deep inside a gas cloud in the Large Magellanic Cloud.
“We discovered a jet being launched from this young massive star, and its presence is a signpost for ongoing disc accretion,”
McLeod says. But to confirm that such a disc was indeed present, the team needed to measure the movement of the dense gas around the star.
With the combined capabilities of ESO’s Very Large Telescope (VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, a disc around a young massive star in another galaxy has been observed. Observations from the Multi Unit Spectroscopic Explorer (MUSE) on the VLT, left, show the parent cloud LHA 120-N 180B in which this system, dubbed HH 1177, was first observed. The image at the centre shows the jets that accompany it. The top part of the jet is aimed slightly towards us and thus blueshifted; the bottom one is receding from us and thus redshifted. Observations from ALMA, right, then revealed the rotating disc around the star, similarly with sides moving towards and away from us.
As matter is pulled towards a growing star, it cannot fall directly onto it; instead, it flattens into a spinning disc around the star. Closer to the centre, the disc rotates faster, and this difference in speed is the smoking gun that shows astronomers an accretion disc is present.
“The frequency of light changes depending on how fast the gas emitting the light is moving towards or away from us,”
explains Jonathan Henshaw, a research fellow at Liverpool John Moores University in the UK, and co-author of the study.
“This is precisely the same phenomenon that occurs when the pitch of an ambulance siren changes as it passes you and the frequency of the sound goes from higher to lower.”
The detailed frequency measurements from ALMA allowed the authors to distinguish the characteristic spin of a disc, confirming the detection of the first disc around an extragalactic young star.
Massive stars, like the one observed here, form much more quickly and live far shorter lives than low-mass stars like our Sun. In our galaxy, these massive stars are notoriously challenging to observe and are often obscured from view by the dusty material from which they form at the time a disc is shaping around them. However, in the Large Magellanic Cloud, a galaxy 160 000 light-years away, the material from which new stars are being born is fundamentally different from that in the Milky Way. Thanks to the lower dust content, HH 1177 is no longer cloaked in its natal cocoon, offering astronomers an unobstructed, if far away, view of star and planet formation.
“We are in an era of rapid technological advancement when it comes to astronomical facilities,” McLeod says. “Being able to study how stars form at such incredible distances and in a different galaxy is very exciting.”
