Astronomy Archives

July 19, 2023July 19, 2023 by Matt Williams

Star Birth and Death Seen Near the Beginning of Time

An artist's illustration of the Universe's first stars, called Population 3 stars. Pop 3 stars would have been much more massive than most stars today, and would have burned hot and blue. Their lifetimes would've been much shorter than stars like our Sun. Credit: Wikimedia Commons

Until recently, astronomers could not observe the first stars and galaxies that formed in the Universe. This occurred during what is known as the “Cosmic Dark Ages,” a period that took place between 380,000 and 1 billion years after the Big Bang. Thanks to next-generation instruments like the James Webb Space Telescope (JWST), improved methods and software, and updates to existing observatories, astronomers are finally piercing the veil of this era and getting a look at how the Universe as we know it began.

This includes new observations from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which obtained images of a stellar nursery inside a galaxy roughly 13.2 billion light-years away in the constellation Eridanus. This galaxy has a redshift value of more than 8.3, corresponding to when the Universe was less than 1 billion years old. The images discerned the sites of star formation and possible star death inside a nebula (MACS0416_Y1) located within this galaxy. This represents a major milestone for astronomy as this is the farthest distance such structures have been observed in our Universe.

July 14, 2023July 14, 2023 by Nancy Atkinson

Afghanistan Students for the International Olympiad in Astronomy & Astrophysics Need Your Help

Students from the Kayhana astronomy organization in Afghanistan. Image courtesy of Amena Karimyan.

The 16th International Olympiad on Astronomy and Astrophysics (IOAA) will be held this year in Silesia, Poland on August 10-20, 2023. 265 students from 53 countries will take part in this annual competition that challenges select high school students from around the world in astronomical science.

One group of student in particular stands out in overcoming incredible odds to qualify for participation in this event, and they need financial help to be able to attend. Student from Afghanistan have been restricted from publicly participating in science activities like astronomy due to the presence of the Taliban. Additionally, a majority of the students from Afghanistan who qualified to attend the IOAA are girls, and since the Taliban returned to power nearly two years ago, they have resumed pushing women and girls out of public life and out of schools.

July 14, 2023July 14, 2023 by Matt Williams

China Has Begun Launching its Own Satellite Internet Network

China launches a new satellite to test satellite internet technology at the Jiuquan Satellite Launch Center, July 9th, 2023. Credit: CMG

Since 2019, Elon Musk and SpaceX have led the charge to create high broadband satellite internet services. As of May 2023, the Starlink constellation consisted of over 4,000 satellites operating in Low Earth Orbit (LEO) and roughly 1.5 million subscribers worldwide. Several competitors began launching constellations years before Starlink began, and several companies have emerged since. This includes HughesNet, OneWeb, and Amazon’s Kuiper Systems. But Starlink’s latest challenger could be its most fearsome yet: a company in China backed by the Beijing government!

On Sunday, July 9th, a prototype internet satellite was launched aboard a Long March 2C carrier rocket from China’s Jiuquan Satellite Launch Center in Inner Mongolia. The satellite has since entered a predetermined orbit, where it will conduct several tests to validate the broadband satellite technology. The long-term aim of the project is to create a constellation of 13,000 satellites code-named “Guo Wang,” – which loosely translates to “state network” in Mandarin – reflecting Beijing’s vision for a state-run share of the satellite internet market.

July 13, 2023July 14, 2023 by Matt Williams

The Final Flight of Ariane 5 Means That Europe is Out of Rockets

The Ariane 5 rocket taking off from Europe's Spaceport in French Guyana. Credit: ESA-CNES

The Ariane 5 rocket, developed by Arianespace for the European Space Agency (ESA), has had a good run! The rocket series made its debut in 1996 and has been the workhorse of the ESA for decades, performing a total of 117 launches from Europe’s Spaceport in French Guiana. The many payloads it has sent to space include resupply missions to the International Space Station (ISS), the BepiColombo probe, the comet-chasing Rosetta spacecraft, the James Webb Space Telescope (JWST), the JUpiter ICy moons Explorer (JUICE), and countless communication and science satellites.

Alas, all good things must come to an end. In 2020, Arianespace and the ESA signed contracts for the rocket’s last eight launches before the Ariane 6 (a heavier two-stage launcher) would succeed it. The Ariane 5‘s final flight (VA261) lifted off from Europe’s Spaceport at 06:00 PM EST (03:00 PM PST) on July 5th, 2023, and placed two payloads into their planned geostationary transfer orbits (GTO) about 33 minutes later. On the downside, this means that the ESA is effectively out of launch vehicles until the Ariane 6 makes its debut next year.

July 13, 2023July 13, 2023 by Matt Williams

How Old is That Star? Ask a Computer

An open cluster of stars known as IC 4651, a stellar grouping that lies at in the constellation of Ara (The Altar). Credit: ESO

When measuring distances in the Universe, astronomers rely on what is known as the “Distance Ladder” – a succession of methods by which distances are measured to objects that are increasingly far from us. But what about age? Knowing with precision how old stars, star clusters, and galaxies are is also paramount to determining how the cosmos has evolved. Thanks to a new machine learning technique developed by researchers from Keele University, astronomers may have established the first rung on a “cosmic age ladder.”

July 13, 2023July 13, 2023 by Brian Koberlein

Celebrate a Year of JWST With This Ludicrous Image of Rho Ophiuchi

JWST image of the star forming region Rho Ophiuchi. Credit: NASA, ESA, CSA, STScI, Klaus Pontoppidan (STScI)

Astronomy is driven by data. We take spectra of distant galaxies, plot the temperatures and brightness of main sequence stars, and graph the gravitational chirps of merging black holes. All of this data allows us to understand the universe around us. We don’t need images to do that, just data. But we still capture images even when we already have the data. We value them for their wondrous beauty, and for the stories they tell. This is why to celebrate a year of gathering data the James Webb Space Telescope (JWST) released a stunningly beautiful image that also tells a wondrous tale.

July 12, 2023June 13, 2023 by Paul M. Sutter

Magnetar Glitches, Fast Radio Bursts, And…Asteroids???

A massive flare ejected from a magnetar.

Recently astronomers have been able to associate two seemingly unrelated phenomena: an explosive event known as a fast radio burst and the change in speed of a spinning magnetar. And now new research suggests that the cause of both of these is the destruction of an asteroid by a magnetar.

July 11, 2023June 13, 2023 by Paul M. Sutter

Dynamical Dark Energy Might Explain Strange 21-cm Signal

An artist's representation of what the first stars to light up the universe might have looked like in the Cosmic Dawn -- when early stars and galaxies were coming together. Image Credit: NASA/WMAP Science Team

Dark energy may evolve in time, and it may even connect through a new force of nature with dark matter. And a researcher believes that we may have already seen evidence for this.

July 10, 2023July 10, 2023 by Matt Williams

A Black Hole Switched On in the Blink of an Eye

This artist’s impression depicts a rapidly spinning supermassive black hole surrounded by an accretion disc. This thin disc of rotating material consists of the leftovers of a Sun-like star which was ripped apart by the tidal forces of the black hole. Shocks in the colliding debris as well as heat generated in accretion led to a burst of light, resembling a supernova explosion. Credit: ESO, ESA/Hubble, M. Kornmesser

In 2019, a team of astronomers led by Dr. Samantha Oates of the University of Birmingham discovered one of the most powerful transients ever seen – where astronomical objects change their brightness over a short period. Oates and her colleagues found this object, known as J221951-484240 (or J221951), using the Ultra-Violet and Optical Telescope (UVOT) on NASA’s Neil Gehrels Swift Observatory while searching for the source of a gravitational wave (GW) that was thought to be caused by two massive objects merging in our galaxy.

Multiple follow-up observations were made using the UVOT and Swift’s other instruments – the Burst Alert Telescope (BAT) and X-Ray Telescope (XRT), the Hubble Space Telescope, the South African Large Telescope (SALT), the Wide-field Infrared Survey Explorer (WISE), the ESO’s Very Large Telescope (VLT), the Australia Telescope Compact Array (ATCA), and more. The combined observations and spectra revealed that the source was a supermassive black hole (SMBH) in a distant galaxy that mysteriously “switched on,” becoming one of the most dramatic bursts of brightness ever seen with a black hole.

July 7, 2023July 7, 2023 by Brian Koberlein

Astronomers Map out the Radio Waves Coming From Large Satellite Constellations

Illustration Starlink satellites over LOFAR. Credit: Daniëlle Futselaar

Satellite internet constellations such as Starlink have the potential to make connect nearly the entire world. Starlink already provides internet access to remote areas long excluded by the internet revolution, and other projects such as OneWeb and Project Kuiper are in the works. But there are side effects to creating a massive array of low-orbit satellites, and one of them is the potentially serious effect on astronomy.