ESO: Explaining the ups and downs in a pulsar’s brightness

August 30, 2023 TopSpacer

A new report from the European Southern Observatory (ESO):

ESO telescopes help unravel pulsar puzzle

This artist’s impression shows the pulsar PSR J1023+0038 stealing gas from its companion star. This gas accumulates in a disc around the pulsar, slowly falls towards it, and is eventually expelled in a narrow jet. In addition, there is a wind of particles blowing away from the pulsar, represented here by a cloud of very small dots. This wind clashes with the infalling gas, heating it up and making the system glow brightly in X-rays and ultraviolet and visible light. Eventually, blobs of this hot gas are expelled along the jet, and the pulsar returns to the initial, fainter state, repeating the cycle. This pulsar has been observed to switch incessantly between these two states every few seconds or minutes.

With a remarkable observational campaign that involved 12 telescopes both on the ground and in space, including three European Southern Observatory (ESO) facilities, astronomers have uncovered the strange behaviour of a pulsar, a super-fast-spinning dead star. This mysterious object is known to switch between two brightness modes almost constantly, something that until now has been an enigma. But astronomers have now found that sudden ejections of matter from the pulsar over very short periods are responsible for the peculiar switches.

“We have witnessed extraordinary cosmic events where enormous amounts of matter, similar to cosmic cannonballs, are launched into space within a very brief time span of tens of seconds from a small, dense celestial object rotating at incredibly high speeds,”

says Maria Cristina Baglio, researcher at New York University Abu Dhabi, affiliated with the Italian National Institute for Astrophysics (INAF), and the lead author of the paper published today in Astronomy & Astrophysics.

A pulsar is a fast-rotating, magnetic, dead star that emits a beam of electromagnetic radiation into space. As it rotates, this beam sweeps across the cosmos — much like a lighthouse beam scanning its surroundings — and is detected by astronomers as it intersects the line of sight to Earth. This makes the star appear to pulse in brightness as seen from our planet.

PSR J1023+0038, or J1023 for short, is a special type of pulsar with a bizarre behaviour. Located about 4500 light-years away in the Sextans constellation, it closely orbits another star. Over the past decade, the pulsar has been actively pulling matter off this companion, which accumulates in a disc around the pulsar and slowly falls towards it.

Since this process of accumulating matter began, the sweeping beam virtually vanished and the pulsar started incessantly switching between two modes. In the ‘high’ mode, the pulsar gives off bright X-rays, ultraviolet and visible light, while in the ‘low’ mode it’s dimmer at these frequencies and emits more radio waves. The pulsar can stay in each mode for several seconds or minutes, and then switch to the other mode in just a few seconds. This switching has thus far puzzled astronomers.

“Our unprecedented observing campaign to understand this pulsar’s behaviour involved a dozen cutting-edge ground-based and space-borne telescopes,”

says Francesco Coti Zelati, a researcher at the Institute of Space Sciences, Barcelona, Spain, and co-lead author of the paper. The campaign included ESO’s Very Large Telescope (VLT) and ESO’s New Technology Telescope (NTT), which detected visible and near-infrared light, as well as the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner. Over two nights in June 2021, they observed the system make over 280 switches between its high and low modes.

“We have discovered that the mode switching stems from an intricate interplay between the pulsar wind, a flow of high-energy particles blowing away from the pulsar, and matter flowing towards the pulsar,”

says Coti Zelati, who is also affiliated with INAF.

In the low mode, matter flowing towards the pulsar is expelled in a narrow jet perpendicular to the disc. Gradually, this matter accumulates closer and closer to the pulsar and, as this happens, it is hit by the wind blowing from the pulsating star, causing the matter to heat up. The system is now in a high mode, glowing brightly in the X-ray, ultraviolet and visible light. Eventually, blobs of this hot matter are removed by the pulsar via the jet. With less hot matter in the disc, the system glows less brightly, switching back into the low mode.

While this discovery has unlocked the mystery of J1023’s strange behaviour, astronomers still have much to learn from studying this unique system and ESO’s telescopes will continue to help astronomers observe this peculiar pulsar. In particular, ESO’s Extremely Large Telescope (ELT), currently under construction in Chile, will offer an unprecedented view of J1023’s switching mechanisms.

“The ELT will allow us to gain key insights into how the abundance, distribution, dynamics, and energetics of the inflowing matter around the pulsar are affected by the mode switching behavior,”

concludes Sergio Campana, Research Director at the INAF Brera Observatory and coauthor of the study.

Links

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An Infinity of Worlds:
Cosmic Inflation and the Beginning of the Universe

In Space Infrastructure, Living in Space, Space Systems

Videos: “Space to Ground” & other space habitat reports – Aug.29.2023

August 29, 2023 TopSpacer

This week’s selection of videos about space stations and living in space including NASA’s latest Space to Ground report for the International Space Station:

** Hurricane Idalia seen from the International Space Station – VideoFromSpace

The International Space Station flew over Hurricane Idalia on Aug. 29, 2023.

** Crew-7 | Approach and Docking – SpaceX

On Sunday, August 27 at 9:16 a.m. ET, SpaceX’s Dragon autonomously docked with the International Space Station. Almost 30 hours earlier at 3:27 a.m. ET, Falcon 9 launched the spacecraft and Crew-7 to orbit from Launch Complex 39A (LC-39A) at NASA’s Kennedy Space Center in Florida.

During their time on the orbiting laboratory, the crew will conduct science and technology demonstrations to prepare for human exploration beyond low-Earth orbit and to benefit humanity on Earth.

** NASA’s SpaceX Crew-7 Flight Day 2 Highlights – NASA Video

NASA’s SpaceX Dragon Endurance spacecraft carrying NASA astronaut Jasmin Moghbeli, ESA (European Space Agency) astronaut Andreas Mogensen, JAXA (Japan Aerospace Exploration Agency) astronaut Satoshi Furukawa, and Roscosmos cosmonaut Konstantin Borisov autonomously docked to the space-facing port of the Harmony module of the International Space Station at 9:16 a.m. EDT on Aug. 27 following a launch the day before on the SpaceX Dragon Endurance spacecraft aboard a Falcon 9 rocket from Launch Complex 39A at the agency’s Kennedy Space Center in Florida. Following docking, the quartet opened the hatch and floated onboard the orbital outpost before providing welcoming remarks as their mission aboard the space station began. The four crew members will conduct a long-duration science mission living and working aboard the microgravity laboratory to advance scientific knowledge and demonstrate new technologies for future human and robotic exploration missions. Such research benefits people on Earth and lays the groundwork for future human exploration through the agency’s Artemis missions, which will send astronauts to the Moon to prepare for future expeditions to Mars.

** NASA’s SpaceX Crew-7 Mission Overview – NASA Johnson

NASA’s SpaceX Crew-7 mission will carry NASA astronaut Jasmin Moghbeli, ESA (European Space Agency) astronaut Andreas Mogensen, JAXA (Japan Aerospace Exploration Agency) astronaut Satoshi Furukawa, and Konstantin Borisov of Roscosmos to the International Space Station. A SpaceX Falcon 9 rocket and Dragon spacecraft will launch from Launch Complex 39A at NASA’s Kennedy Space Center in Florida on the company’s seventh crew rotation mission for NASA. Learn more about the crew and mission: https://www.nasa.gov/feature/what-you…

** The Science of NASA’s SpaceX Crew-6 Mission – NASA

After launching to the International Space Station on March 2, 2023, NASA’s SpaceX Crew-6 mission is wrapping up its time in orbit, with a return to Earth in early September 2023.

NASA astronauts Stephen Bowen and Woody Hoburg, UAE (United Arab Emirates) astronaut Sultan Alneyadi, and Roscosmos cosmonaut Andrey Fedyaev spent their months on the orbiting lab conducting scientific investigations and technology demonstrations, including running a student robotic challenge, studying plant genetic adaptations to space, and monitoring human health in microgravity to prepare for exploration beyond low Earth orbit and to benefit life on Earth.

The astronauts also released Saskatchewan’s first satellite, which tests a new radiation detection and protection system derived from melanin.

Learn more: https://go.nasa.gov/3OOOR3l

** Expedition 69 NASA’s SpaceX Crew-6 Talks with Media Before Station Departure – Aug. 23, 2023 – NASA Video

Aboard the International Space Station NASA astronauts Steve Bowen and Woody Hoburg, UAE (United Arab Emirates) astronaut Sultan Alneyadi, and Roscosmos cosmonaut Andrey Fedyaev gave remarks about their mission during a news conference August 23. The Crew-6 astronauts have been aboard the space station since March and will return to Earth via a parachute assisted splashdown in September. The four crew members have been living and working aboard the microgravity laboratory to advance scientific knowledge and demonstrate new technologies for future human and robotic exploration missions. Such research benefits people on Earth and lays the groundwork for future human exploration through the agency’s Artemis missions, which will send astronauts to the Moon to prepare for future expeditions to Mars.

** Expedition 69 Progress 85 Cargo Ship Docks to Space Station – Aug. 24, 2023 – NASA Video

The uncrewed Roscosmos ISS Progress 85 cargo spacecraft docked to the aft port of the Zvezda Service Module August 24 after launching to the International Space Station from the Baikonur Cosmodrome in Kazakhstan August 22 on a Soyuz booster rocket. Progress is filled with almost three tons of supplies and cargo and will remain docked to the space station until early next year.

** Timelapse showing Canadarm2 operations with Nanoracks Bishop Airlock – ISS Above

“On Monday, August 28, 2023, Robotics ground controllers plan to perform the Gambit Sortie to demate NRAL, install Gambit on an exterior NRAL site, and then remate NRAL to Node 3. The objective of Gambit is to evaluate and catalog performance of the NRAL external sites. Gambit will be moved to all six external NRAL sites throughout the course of the investigation, and various sensors measure temperature, vibrations, and radiation to characterize each site. Results could support design and development of future science investigations that use these sites.” – NASA Station Report.

** ISSRDC Day2 Lightning Talk – Vast: Building the First Crewed, Independent Space Station – ISS National Lab

** Shenzhou-16 Crew Reap Good Harvest in Space Planting Experiment – CCTV Video News Agency

The space vegetable planting experiment conducted by the Shenzhou-16 crew who have been in orbit for almost three months has yielded a good harvest.

** Live Video from the International Space Station (Official NASA Stream) – NASA

Watch live video from the International Space Station, including inside views when the crew aboard the space station is on duty. Views of Earth are also streamed from an external camera located outside of the space station. During periods of signal loss due to handover between communications satellites, a blue screen is displayed.

The space station orbits Earth about 250 miles (425 kilometers) above the surface. An international partnership of five space agencies from 15 countries operates the station, and it has been continuously occupied since November 2000. It’s a microgravity laboratory where science, research, and human innovation make way for new technologies and research breakthroughs not possible on Earth. More: https://go.nasa.gov/3CkVtC8

Did you know you can spot the station without a telescope? It looks like a fast-moving star, but you have to know when to look up. Sign up for text messages or email alerts to let you know when (and where) to spot the station and wave to the crew: https://spotthestation.nasa.gov

====

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Rockets, Space industry, Space Systems

Videos: A SpaceX overview + Starship reports

August 28, 2023 TopSpacer

Here is a sampling of videos about SpaceX and the Starship project.

** Public presentations about SpaceX are usually provided by Elon Musk or Gwynne Shotwell. However, here is an excellent overview of the company given by Kiko Dontchev, Vice President of Launch, at the Summit At Sea event last May.

Curious how SpaceX went from 13 launches in 2019 to pacing for 100 in 2023? As VP of Launch at SpaceX, Kiko Dontchev goes into work every day with the simple goal of making space travel as accessible as air travel, and he is well on his way. In this talk, Kiko will dive into SpaceX’s exponential growth approach, Elon’s problem-solving algorithm, and becoming the most prolific launcher of all time.

** Several new media sources have risen in the past couple of years that report extensively on SpaceX Starship related activities. A sampling of these include:

LabPadre at YouTube, including live webcams
RGV Aerial Photography – YouTube
NASASpaceflight at YouTube, including live webcams
Marcus House – YouTube
What about it!? – YouTube
CSI Starbase – YouTube
Starship Gazer – YouTube

Here, for example, are three reports on recent Starship developments:

** The design, development, and commercial potential of Starship are presented in the SpaceX Starship report, for which I was the primary author. Initially published by NewSpace Global in March 2023, we updated it in May to include coverage of the first flight test.

==================

Check out the
The Lurio Report
for news and analysis of key developments in NewSpace

The latest issue:
Starships’ Second Flight, Blue HLS, Return Sustainably
Vol. 18, No. 2, July 16, 2023

Space Frontier Foundation Award for NewSpace Journalism

==================

Astronomy, Education, Space Science

ESO: Dark spot on Neptune observed by telescope on Earth for first time

August 24, 2023 TopSpacer

A new report from the European Southern Observatory (ESO):

Mysterious Neptune dark spot detected from Earth for the first time

This image shows Neptune observed with the MUSE instrument at ESO’s Very Large Telescope (VLT). At each pixel within Neptune, MUSE splits the incoming light into its constituent colours or wavelengths. This is similar to obtaining images at thousands of different wavelengths all at once, which provides a wealth of valuable information to astronomers. The image to the right combines all colours captured by MUSE into a “natural” view of Neptune, where a dark spot can be seen to the upper-right. Then we see images at specific wavelengths: 551 nanometres (blue), 831 nm (green), and 848 nm (red); note that the colours are only indicative, for display purposes. The dark spot is most prominent at shorter (bluer) wavelengths. Right next to this dark spot MUSE also captured a small bright one, seen here only in the middle image at 831 nm and located deep in the atmosphere. This type of deep bright cloud had never been identified before on the planet. The images also show several other shallower bright spots towards the bottom-left edge of Neptune, seen at long wavelengths. Imaging Neptune’s dark spot from the ground was only possible thanks to the VLT’s Adaptive Optics Facility, which corrects the blur caused by atmospheric turbulence and allows MUSE to obtain crystal clear images. To better highlight the subtle dark and bright features on the planet, the astronomers carefully processed the MUSE data, obtaining what you see here.

Using ESO’s Very Large Telescope (VLT), astronomers have observed a large dark spot in Neptune’s atmosphere, with an unexpected smaller bright spot adjacent to it. This is the first time a dark spot on the planet has ever been observed with a telescope on Earth. These occasional features in the blue background of Neptune’s atmosphere are a mystery to astronomers, and the new results provide further clues as to their nature and origin.

Large spots are common features in the atmospheres of giant planets, the most famous being Jupiter’s Great Red Spot. On Neptune, a dark spot was first discovered by NASA’s Voyager 2 in 1989, before disappearing a few years later.

“Since the first discovery of a dark spot, I’ve always wondered what these short-lived and elusive dark features are,”

says Patrick Irwin, Professor at the University of Oxford in the UK and lead investigator of the study published today in Nature Astronomy.

Irwin and his team used data from ESO’s VLT to rule out the possibility that dark spots are caused by a ‘clearing’ in the clouds. The new observations indicate instead that dark spots are likely the result of air particles darkening in a layer below the main visible haze layer, as ices and hazes mix in Neptune’s atmosphere.

Coming to this conclusion was no easy feat because dark spots are not permanent features of Neptune’s atmosphere and astronomers had never before been able to study them in sufficient detail. The opportunity came after the NASA/ESA Hubble Space Telescope discovered several dark spots in Neptune’s atmosphere, including one in the planet’s northern hemisphere first noticed in 2018. Irwin and his team immediately got to work studying it from the ground — with an instrument that is ideally suited to these challenging observations.

Using the VLT’s Multi Unit Spectroscopic Explorer (MUSE), the researchers were able to split reflected sunlight from Neptune and its spot into its component colours, or wavelengths, and obtain a 3D spectrum [1]. This meant they could study the spot in more detail than was possible before.

“I’m absolutely thrilled to have been able to not only make the first detection of a dark spot from the ground, but also record for the very first time a reflection spectrum of such a feature,”

says Irwin.

This image shows Neptune observed with the MUSE instrument at ESO’s Very Large Telescope. At each pixel within Neptune, MUSE splits the incoming light into its constituent colours or wavelengths. This is similar to obtaining images at thousands of different wavelengths all at once, which provides a wealth of valuable information to astronomers. This image combines all colours captured by MUSE into a “natural” view of Neptune, where a dark spot can be seen to the upper-right.

Since different wavelengths probe different depths in Neptune’s atmosphere, having a spectrum enabled astronomers to better determine the height at which the dark spot sits in the planet’s atmosphere. The spectrum also provided information on the chemical composition of the different layers of the atmosphere, which gave the team clues as to why the spot appeared dark.

The observations also offered up a surprise result.

“In the process we discovered a rare deep bright cloud type that had never been identified before, even from space,”

says study co-author Michael Wong, a researcher at the University of California, Berkeley, USA. This rare cloud type appeared as a bright spot right beside the larger main dark spot, the VLT data showing that the new ‘deep bright cloud’ was at the same level in the atmosphere as the main dark spot. This means it is a completely new type of feature compared to the small ‘companion’ clouds of high-altitude methane ice that have been previously observed.

With the help of ESO’s VLT, it is now possible for astronomers to study features like these spots from Earth. “This is an astounding increase in humanity’s ability to observe the cosmos.

At first, we could only detect these spots by sending a spacecraft there, like Voyager. Then we gained the ability to make them out remotely with Hubble. Finally, technology has advanced to enable this from the ground,”

concludes Wong, before adding, jokingly:

“This could put me out of work as a Hubble observer!”

Notes

[1] MUSE is a 3D spectrograph that allows astronomers to observe the entirety of an astronomical object, like Neptune, in one go. At each pixel, the instrument measures the intensity of light as a function of its colour or wavelength. The resulting data form a 3D set in which each pixel of the image has a full spectrum of light. In total, MUSE measures over 3500 colours. The instrument is designed to take advantage of adaptive optics, which corrects for the turbulence in the Earth’s atmosphere, resulting in sharper images than otherwise possible. Without this combination of features, studying a Neptune dark spot from the ground would not have been possible.

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An Infinity of Worlds:
Cosmic Inflation and the Beginning of the Universe

In Space Infrastructure, Living in Space, Space Systems

Videos: “Space to Ground” & other space habitat reports – Aug.21.2023

August 21, 2023 TopSpacer

This week’s selection of videos about space stations and living in space including NASA’s latest Space to Ground report for the International Space Station:

** NASA’s SpaceX Crew-7 Mission to the Space Station (Official Trailer) – NASA

An international crew is preparing to launch to the International Space Station aboard NASA’s SpaceX Crew-7 mission.

NASA astronaut Jasmin Moghbeli, ESA (European Space Agency) astronaut Andreas Mogensen, JAXA (Japan Aerospace Exploration Agency) astronaut Satoshi Furukawa, and cosmonaut Konstantin Borisov of Roscosmos will perform research technology demonstrations, science experiments, and maintenance activities aboard the microgravity laboratory.

Crew-7 is targeted to launch no earlier than 3:49 a.m. EDT on Friday, Aug. 25 from Launch Complex 39A at Kennedy. As part of the agency’s Commercial Crew Program, Crew-7 marks the eighth human spaceflight mission supported by a SpaceX Dragon spacecraft and the seventh crew rotation mission to the space station since 2020 for NASA.

You can watch the launch live on NASA TV, NASA.gov, the NASA app, and on social media (@NASA).

Learn more about the Crew-7 mission here: https://blogs.nasa.gov/crew-7/

** Gateway: A New Era of Utilization in Deep Space – ISS National Lab

** ISSRDC Day1 Fireside Chat – Getting to the Heart of the Matter in LEO – ISS National Lab

** Full Bishop Airlock Animation – Nanoracks

** Progress MS-22 undocking and departure – SciNews

The Progress MS-22 spacecraft autonomously undocked from the aft port of the Zvezda service module, on the International Space Station, on 20 August 2023, at 23:50 UTC. Progress MS-22 (ISS Progress 83 mission) delivered about three tons of food, fuel, and supplies for the Expedition 68 crew aboard the International Space Station.
Credit: NASA/Roscosmos

** Experiment Cabinet on China’s Space Station Versatile for Sci-Tech Verification – CCTV Video News Agency

Standing at two meters tall and one meter wide and with a design life of 15 years, the Space Basic Experiment Cabinet mounted on one of the lab modules of China’s Tiangong Space Station has served as a versatile space technology verification platform, facilitating fruitful scientific research achievements in a microgravity environment, since its launch into orbit last year.

** China Completes In-Orbit Observation of Conductive Ring Wear Debris – CCTV Video News Agency

China has completed its first in-orbit observation of the generation process and clustering phenomenon of conductive ring wear debris on the country’s space station Tiangong.