Category Archives: Astronomy

Astronomy, Education, Space participation

Night sky highlights for December 2022

December 1, 2022 TopSpacer

** What’s Up: December 2022 Skywatching Tips from NASA – NASA JPL

What are some skywatching highlights in December 2022?
The Moon sweeps past Jupiter twice this month, and actually covers Mars completely, in an event called an occultation, on Dec. 7. The event is visible across the U.S., except for the Southeast and East Coast, where the Moon will graze closely past Mars. And throughout the month, you can find Pegasus, the winged stallion, high overhead in the south.

0:00 Intro
0:11 Moon & planet highlights
0:38 Occultation: Mars disappears
1:54 The constellation Pegasus
3:12 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….

** Tonight’s Sky: March – Space Telescope Science Institute – Tonight’s Sky

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.

** What to see in the night sky: December 2022 – BBC Sky at Night Magazine

Pete Lawrence and Paul Abel reveal this month’s night-sky highlights, including Mars at opposition, a lunar occultation of Mars, the Geminid meteor shower, the Ursid meteor shower and the best targets to see in the Orion constellation.

** Sky & Telescope’s Sky Tour Podcast – December 2022 – 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 learn about the #solstice, #Mars, the #Geminids #meteor shower, and winter’s bright #stars.

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.

Learn more about #observing and #stargazing on our website, https://skyandtelescope.org/ and subscribe to our monthly magazine at https://skyandtelescope.org/subscribe.

This video is sponsored by Celestron – https://www.celestron.com/.

ESO: Distant black hole swallowing a star discovered in visible light

November 30, 2022 TopSpacer

The latest report from the European Southern Observatory (ESO):

Most distant detection of a black hole swallowing a star

This artist’s impression illustrates how it might look when a star approaches too close to a black hole, where the star is squeezed by the intense gravitational pull of the black hole. Some of the star’s material gets pulled in and swirls around the black hole forming the disc that can be seen in this image. In rare cases, such as this one, jets of matter and radiation are shot out from the poles of the black hole. In the case of the AT2022cmc event, evidence of the jets was detected by various telescopes including the VLT, which determined this was the most distant example of such an event.

Earlier this year, the European Southern Observatory’s Very Large Telescope (ESO’s VLT) was alerted after an unusual source of visible light had been detected by a survey telescope. The VLT, together with other telescopes, was swiftly repositioned towards the source: a supermassive black hole in a distant galaxy that had devoured a star, expelling the leftovers in a jet. The VLT determined it to be the furthest example of such an event to have ever been observed. Because the jet is pointing almost towards us, this is also the first time it has been discovered with visible light, providing a new way of detecting these extreme events.

Stars that wander too close to a black hole are ripped apart by the incredible tidal forces of the black hole in what is known as a tidal disruption event (TDE). Approximately 1% of these cause jets of plasma and radiation to be ejected from the poles of the rotating black hole. In 1971, the black hole pioneer John Wheeler[1] introduced the concept of jetted-TDEs as “a tube of toothpaste gripped tight about its middle,” causing the system to “squirt matter out of both ends.”

“We have only seen a handful of these jetted-TDEs and they remain very exotic and poorly understood events,”

says Nial Tanvir from the University of Leicester in the UK, who led the observations to determine the object’s distance with the VLT. Astronomers are thus constantly hunting for these extreme events to understand how the jets are actually created and why such a small fraction of TDEs produce them.

As part of this quest many telescopes, including the Zwicky Transient Facility (ZTF) in the US, repeatedly survey the sky for signs of short-lived, often extreme, events that could then be studied in much greater detail by telescopes such as ESO’s VLT in Chile.

“We developed an open-source data pipeline to store and mine important information from the ZTF survey and alert us about atypical events in real time,”

explains Igor Andreoni, an astronomer at the University of Maryland in the US who co-led the paper published today in Nature together with Michael Coughlin from the University of Minnesota.

In February of this year the ZTF detected a new source of visible light. The event, named AT2022cmc, was reminiscent of a gamma ray burst — the most powerful source of light in the Universe. The prospect of witnessing this rare phenomenon prompted astronomers to trigger several telescopes from across the globe to observe the mystery source in more detail. This included ESO’s VLT, which quickly observed this new event with the X-shooter instrument. The VLT data placed the source at an unprecedented distance for these events: the light produced from AT2022cmc began its journey when the universe was about one third of its current age.

A wide variety of light, from high energy gamma rays to radio waves, was collected by 21 telescopes around the world. The team compared these data with different kinds of known events, from collapsing stars to kilonovae. But the only scenario that matched the data was a rare jetted-TDE pointing towards us. Giorgos Leloudas, an astronomer at DTU Space in Denmark and co-author of this study, explains that

“because the relativistic jet is pointing at us, it makes the event much brighter than it would otherwise appear, and visible over a broader span of the electromagnetic spectrum.“

The VLT distance measurement found AT2022cmc to be the most distant TDE to have ever been discovered, but this is not the only record-breaking aspect of this object.

“Until now, the small number of jetted-TDEs that are known were initially detected using high energy gamma-ray and X-ray telescopes, but this was the first discovery of one during an optical survey,”

says Daniel Perley, an astronomer at Liverpool John Moores University in the UK and co-author of the study. This demonstrates a new way of detecting jetted-TDEs, allowing further study of these rare events and probing of the extreme environments surrounding black holes.

Notes

[1] John Archibald Wheeler is also often credited with coining the term ‘black hole’ in a 1967 speech to NASA.

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ESO: Images of the Cone Nebula, an immense star factory

November 10, 2022 TopSpacer

The latest report from the European Southern Observatory (ESO):

ESO images a wondrous star factory to mark 60 years of collaboration

The Cone Nebula is part of a star-forming region of space, NGC 2264, about 2500 light-years away. Its pillar-like appearance is a perfect example of the shapes that can develop in giant clouds of cold molecular gas and dust, known for creating new stars. This dramatic new view of the nebula was captured with the FOcal Reducer and low dispersion Spectrograph 2 (FORS2) instrument on ESO’s Very Large Telescope (VLT), and released on the occasion of ESO’s 60th anniversary.

For the past 60 years the European Southern Observatory (ESO) has been enabling scientists worldwide to discover the secrets of the Universe. We mark this milestone by bringing you a spectacular new image of a star factory, the Cone Nebula, taken with ESO’s Very Large Telescope (VLT).

On 5 October 1962 five countries signed the convention to create ESO. Now, six decades later and supported by 16 Member States and strategic partners, ESO brings together scientists and engineers from across the globe to develop and operate advanced ground-based observatories in Chile that enable breakthrough astronomical discoveries.

On the occasion of ESO’s 60th anniversary we are releasing this remarkable new image of the Cone Nebula, captured earlier this year with one of ESO’s telescopes and selected by ESO staff. This is part of a campaign marking ESO’s 60^th anniversary and taking place in late 2022, both on social media under the #ESO60years hashtag, and with local events in the ESO Member States and other countries.

In this new image, we see centre-stage the seven-light-year-long pillar of the Cone Nebula, which is part of the larger star-forming region NGC 2264 and was discovered in the late 18th century by astronomer William Herschel. In the sky, we find this horn-shaped nebula in the constellation Monoceros (The Unicorn), a surprisingly fitting name.

Located less than 2500 light-years away, the Cone Nebula is relatively close to Earth, making it a well-studied object. But this view is more dramatic than any obtained before, as it showcases the nebula’s dark and impenetrable cloudy appearance in a way that makes it resemble a mythological creature.

This image from the Digitized Sky Survey (DSS) shows the region of the sky around the Cone Nebula. The nebulous area at the centre of the image is NGC 2264, an area of the sky that includes the Christmas Tree star cluster and the Cone Nebula below it (at the very centre of the frame).

The Cone Nebula is a perfect example of the pillar-like shapes that develop in the giant clouds of cold molecular gas and dust, known for creating new stars. This type of pillar arises when massive, newly formed bright blue stars give off stellar winds and intense ultraviolet radiation that blow away the material from their vicinity. As this material is pushed away, the gas and dust further away from the young stars gets compressed into dense, dark and tall pillar-like shapes. This process helps create the dark Cone Nebula, pointing away from the brilliant stars in NGC 2264.

In this image, obtained with the FOcal Reducer and low dispersion Spectrograph 2 (FORS2) on ESO’s VLT in Chile, hydrogen gas is represented in blue and sulphur gas in red. The use of these filters makes the otherwise bright blue stars, that indicate the recent star formation, appear almost golden, contrasting with the dark cone like sparklers.

This image is just one example of the many stunning and awe-inspiring observations ESO telescopes have made in the past 60 years. While this one was obtained for outreach purposes, the overwhelming majority of ESO’s telescope time is dedicated to scientific observations that have allowed us to capture the first image of an exoplanet, study the black hole at the centre of our home galaxy, and find proof that the expansion of our Universe is accelerating.

Building on our 60 years of experience in astronomy development, discovery and cooperation, ESO continues to chart new territory for astronomy, technology and international collaboration. With our current facilities and ESO’s upcoming Extremely Large Telescope (ELT), we will keep on addressing humanity’s biggest questions about the Universe and enabling unimaginable discoveries.

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Astronomy, Education, Space participation

Night sky highlights for November 2022

November 2, 2022 TopSpacer

** What’s Up: November 2022 Skywatching Tips from NASA – NASA JPL

What are some skywatching highlights in November 2022?

A total lunar eclipse brings some magic to the morning sky on November 8th, and the Leonid meteors peak after midnight on November 18th, with some glare from a 35% full moon. In addition, enjoy pretty views on other days in November when the Moon visits planets Mars and Saturn, and bright star Spica.

0:00 Intro
0:10 Total lunar eclipse
1:25 Moon & planet highlights
2:16 Leonid meteor shower
3:15 Nov ember 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….

** Tonight’s Sky: November – Space Telescope Science Institute – Tonight’s Sky

In November, hunt for the fainter constellations of fall, including Pisces, Aries, and Triangulum. They will guide you to find several galaxies and a pair of white stars. Stay tuned for space-based views of spiral galaxy M74 and the Triangulum Galaxy, which are shown in visible, infrared, and ultraviolet light

** What to see in the night sky: November 2022 – BBC Sky at Night Magazine

Pete Lawrence and Paul Abel reveal the best things to see in the night sky this month, including observing Mars as it approaches opposition, catching Jupiter’s Galilean moons, the Leonid meteor shower, the Orion constellation, the Winter Triangle asterism and the Crab Nebula.

** Sky & Telescope’s Sky Tour Podcast – November 2022 – 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 November episode and learn about the total #lunareclipse, check out three bright #planets in the evening sky, get the lowdown on a celestial queen, and get ready for three #meteor showers.

ESO: VLT captures the vast cloudy remains of the Vela supernova remnant

October 31, 2022 TopSpacer

A report for the Halloween season from the European Southern Observatory (ESO):

ESO captures the ghost of a giant star

This image shows a spectacular view of the orange and pink clouds that make up what remains after the explosive death of a massive star — the Vela supernova remnant. This detailed image consists of 554 million pixels, and is a combined mosaic image of observations taken with the 268-million-pixel OmegaCAM camera at the VLT Survey Telescope, hosted at ESO’s Paranal Observatory. OmegaCAM can take images through several filters that each let the telescope see the light emitted in a distinct colour. To capture this image, four filters have been used, represented here by a combination of magenta, blue, green and red. The result is an extremely detailed and stunning view of both the gaseous filaments in the remnant and the foreground bright blue stars that add sparkle to the image.

A spooky spider web, magical dragons or wispy trails of ghosts? What do you see in this image of the Vela supernova remnant? This beautiful tapestry of colours shows the ghostly remains of a gigantic star, and was captured here in incredible detail with the VLT Survey Telescope, hosted at the European Southern Observatory’s (ESO’s) Paranal site in Chile.

The wispy structure of pink and orange clouds is all that remains of a massive star that ended its life in a powerful explosion around 11 000 years ago. When the most massive stars reach the end of their life, they often go out with a bang, in an outburst called a supernova. These explosions cause shock waves that move through the surrounding gas, compressing it and creating intricate thread-like structures. The energy released heats the gaseous tendrils, making them shine brightly, as seen in this image.

In this 554-million-pixel image, we get an extremely detailed view of the Vela supernova remnant, named after the southern constellation Vela (The Sails). You could fit nine full Moons in this entire image, and the whole cloud is even larger. At only 800 light-years away from Earth, this dramatic supernova remnant is one of the closest known to us.

As it exploded, the outermost layers of the progenitor star were ejected into the surrounding gas, producing the spectacular filaments that we observe here. What remains of the star is an ultra-dense ball in which the protons and electrons are forced together into neutrons — a neutron star. The neutron star in the Vela remnant, placed slightly outside of this image to the upper left, happens to be a pulsar that spins on its own axis at an incredible speed of more than 10 times per second.

Dive into the details of the Vela supernova remnant with these 12 highlights, each showing a different intricate part of the beautiful pink and orange gaseous clouds and the bright stars in the foreground and background.

This image is a mosaic of observations taken with the wide-field camera OmegaCAM at the VLT Survey Telescope (VST), hosted at ESO’s Paranal Observatory in Chile. The 268-million-pixel camera can take images through several filters that let through light of different colours. In this particular image of the Vela remnant, four different filters were used, represented here by a combination of magenta, blue, green and red.

The VST is owned by The National Institute for Astrophysics in Italy, INAF, and with its 2.6-metre mirror it is one of the largest telescopes dedicated to surveying the night sky in visible light. This image is an example from such a survey: the VST Photometric Hα Survey of the Southern Galactic Plane and Bulge (VPHAS+). For over seven years, this survey has mapped a considerable portion of our home galaxy, allowing astronomers to better understand how stars form, evolve and eventually die.