Space News & Blog Articles

Look at most spiral or barred spiral galaxies and you will see multiple regions where stars are forming. These star forming regions are comprised of mostly hydrogen gas with a few other elements for good measure. The first galaxies in the Universe had huge supplies of this star forming gas. Left unchecked they could have burned through the gas quickly, generating enormous amounts of star formation. Life fast though and die young for such an energetic burst of star formation would soon fizzle out leaving behind dead and dying stars. In some way it seems, galaxies seem to regulate their star formation thanks to supermassive black holes at their centre. 

The first galaxies formed about 400 to 700 million years after the Big Bang, during the Epoch known as Reionization. These early galaxies were small and faint, mostly composed of hydrogen and helium, and contained dense clusters of massive, short-lived Population III stars (the first generation of stars.) The intense radiation from these stars ionised the surrounding gas, clearing the fog that permeated space making the universe transparent for the first time. These primordial galaxies began merging and interacting, laying the foundation for the galaxy types seen today.

A new study published in the Monthly Notices of the Royal Astronomical Society explores why galaxies are not as large as astronomers would expect. The research suggests that galaxies, even those that formed first, avoid an early death because they have mechanisms similar to “heart and lungs,” which regulate their “breathing”. Without these regulatory processes our bodies, and galaxies would have aged much faster, resulting in massive galaxies filled with dead and dying stars and devoid of new star formation.

Observations show that galaxies are not so big and full of dying stars having outgrown themselves. It seems something limits their ability to allow gas to form into stars. Astrophysicists at the University of Kent believe they may have the answer: galaxies could be controlling their growth rate through a process not too dissimilar to “breathing.” They compare the supermassive black hole at the centre of a galaxy to a heart and the supersonic jets emerging from the poles with the radiation and gas they emit to airways feeding a pair of lungs.

The supermassive black holes seem to pulse just like a heart. These pulses cause a shock front to oscillate along the jets like a diaphragm inflating and deflating the lungs. This process transmits energy along the jet slowly counteracting the pull of gravity and slowing gas accretion and star formation. The idea was developed by PhD student Carl Richards and his simulations showed a black hole pulsing like a heart. 

Dark matter is curious stuff! As the name suggests, it’s dark making it notoriously difficult to study. Although it’s is invisible, it influences stars in a galaxy through gravity. Now, a team of astronomers have used the Hubble Space Telescope to chart the movements of stars within the Draco dwarf galaxy to detect the subtle gravitational pull of its surrounding dark matter halo. This 3D map required studying nearly two decades of archival data from the Draco galaxy. They found that dark matter piles up more in the centre, as predicted by cosmological models.

Dark matter comprises approximately 27% of the all the mass and energy in the universe but interacts only gravitationally, emitting no light. The idea first – ahem, came to light to explain discrepancies in the rotation curves of galaxies and is detected through its gravitational effects on visible matter. Despite extensive research,  the nature of dark matter remains elusive. Understanding dark matter is crucial for comprehending the composition and evolution of the universe.

Dark matter has often been described as the invisible ‘glue’ that holds galaxies together. Although galaxies are mostly composed of dark matter, understanding its distribution within them provides an opportunity to understand its nature and relevance to the evolution of the galaxy. Computer simulations predict a dense concentration of dark matter at the core of the galaxy, forming a density cusp. However, numerous observations have shown that dark matter appears more uniformly spread throughout galaxies, contradicting these simulations. 

To study dark matter within galaxies, scientists can analyse the movements of stars, which are influenced primarily by the gravitational pull of dark matter. One common method involves using the Doppler Effect to measure the speed of objects in space—observing changes in the wavelength of light as stars move closer to or further from Earth. Along with moving toward or away from us, stars can also move across the sky. This proper motion, when combined with line of sight measurements allow for the creation of the movement of a star in 3D.

Astronomers have employed NASA’s Hubble Space Telescope to study the dynamics of stars within the Draco dwarf galaxy, located about 250,000 light-years from Earth. The Draco galaxy was used because, as a dwarf galaxy, it is relatively small and is believed to have a higher proportion of dark matter than other types of galaxy.

When massive stars detonate as supernovae, they leave often behind a pulsar. These fast rotating stellar corpses have fascinated scientists since their discovery in 1967. One nearby pulsar turns 174 times a second and now, its size has been precisely measured. An instrument on board the International Space Station was used to measure x-ray pulses  from the star. A supercomputer was then used to analyse its properties and found it was 1.4 times the mass of the Sun and measured only 11.4 km across!

The death of a massive stars leads to one of a number of objects but two of them are closely related, the neutron star and the pulsar. Both are formed during the core collapse and supernova explosion that marks the death of a star. All of the components of the atom are squashed together removing all the space between the neutrons to form one MASSIVE neutron. Pulsars are rotating neutron stars with strong magnetic fields that emit beams of electromagnetic radiation from their magnetic poles. These beams become visible from Earth when aligned with our line of sight, creating a pulsating effect, hence the term “pulsar.”

One of the nearest pulsars, PSR J0437-4725 lies at 510 light years in the constellation Pictor. It rotates 174 times per second which means it rotates once in just 5.75 milliseconds. Perhaps more mind blowing than its rotational velocity is its size. Imagine 1.4 times the mass of the Sun squashed up into a ball just 11.4 kilometres across – the Sun is 1.39 million kilometres across by comparison! 

This astonishing result of the pulsars diminutive size are the results of precision measurements by a team fo astronomers at the University of Amsterdam. The scientists used data from the NICER X-ray telescope on the ISS, combining it with a method called pulse profile modelling. The data was fed into Snellius, the Dutch national supercomputer and complex statistical models were created. This allowed them to calculate the star’s radius, assisted by mass measurements from Daniel Reardon (Swinburne University of Technology, Australia) and his colleagues at the Parkes Pulsar Timing Array. Not only were the team able to identify precise dimensions, they were also able to map the temperature distribution of the magnetic poles.

The lead researcher, Devarshi Choudhury was very happy with the results ”Before, we were hoping to be able to calculate the radius accurately. And it would be great if we could show that the hot magnetic poles are not directly opposite each other on the stellar surface. And we just managed to do both!”

Two recent studies published in The Astrophysical Journal discuss findings regarding solar flare properties and a new classification index and the Sun’s magnetic field, specifically what’s called solar magnetic reconnection. These studies hold the potential to help researchers better understand the internal processes of the Sun, specifically pertaining to solar flare activity and space weather. Here, Universe Today discusses these two studies with both lead authors regarding the motivation behind the studies, significant results, and implications on our understanding regarding solar flares and space weather.

The first study discusses new insights into solar flare properties and presents a new solar flare classification index that builds off previous classification indices along with scientific advancements in our understanding of solar flares. So, what was the motivation behind this study?

“The inception of our interest in this study was inspired by work that my advisor, Prof. Adam Kowalski, has done in the last decade in classifying stellar flares using a similar index,” Cole Tamburri, who is a PhD Candidate in the Department of Astrophysical & Planetary Sciences at the University of Colorado Boulder (CU Boulder) and lead author of the study, tells Universe Today. “Traditionally, solar flares are classified according to the peak flux in GOES soft X-ray. However, as our understanding of flare physics has advanced, we’ve learned that there’s much more diversity between flare events which is not captured by the GOES classification system – for example, two events with the same peak intensity might occur over much different time periods (a few minutes, to even a few hours!), which is indicative of significant differences in the physical mechanism.”

The GOES soft X-ray currently classifies solar flares ranging from lowest intensity to highest using classes labeled as A, B, C, M, and X. This data is gathered from the Geostationary Operational Environmental Satellite (GOES) system of four active spacecraft currently in a geosynchronous orbit and operated by the National Oceanic and Atmospheric Administration (NOAA) in the United States. This data is plotted in real-time on the GOES X-ray flux interface available on the NOAA website where users can watch live solar activity while viewing which class the solar flares correspond to on the plot, with the data being updated every 10 minutes.

For the study, the researchers sought to expand upon and improve the GOES classification index by measuring what’s known as impulsiveness, which Tamburri refers to as a “suddenness” of energy release. During a 4-year period between 2010 and 2014, the researchers obtained impulsiveness measurements using Solar Dynamics Observatory/Extreme Ultraviolet Experiment for 1,368 solar flares, categorizing their impulsiveness as low, mid, and high. So, what were the most significant results from this study?

In a new movie titled “Fly Me to the Moon,” a marketing consultant played by Scarlett Johansson uses Tang breakfast drink, Crest toothpaste and Omega watches to give a publicity boost to NASA’s Apollo moon program.

The marketing consultant may be totally fictional. And don’t get me started on the fake moon landing that’s part of the screwball comedy’s plot. But the fact that the makers of Tang, Crest and Omega allied themselves with NASA’s brand in the 1960s is totally real.

More than 50 years later, those companies are still benefiting from the NASA connection, says Richard Jurek, a marketing and public relations executive in the Chicago area who’s one of the authors of “Marketing the Moon: The Selling of the Apollo Lunar Program.”

In the latest episode of the Fiction Science podcast, Jurek says Tang sold poorly when it was introduced in the late 1950s. “But once it was announced that it was being used in the space program and marketed that way, it became a huge bestseller for them, and in fact, still sells more overseas — and is a multibillion-dollar brand today,” he says.

NASA also got something out of the arrangements: The easy-to-use Tang powder was well-suited for the astronauts to mix with water during their flights. The Crest team helped NASA come up with a type of toothpaste that astronauts could swallow rather than spit. And Omega made one heck of a chronograph for the astronauts.

After going eight years and more than 300 launches without a failure, SpaceX had a Falcon 9 rocket launch go awry, resulting in the expected loss of 20 Starlink satellites.

The Federal Aviation Administration said it would oversee an investigation into the anomaly, raising the prospect that dozens of launches could be delayed until the problem is identified and rectified.

As many as 40 Falcon 9 launches are on tap between now and the end of the year — potentially including missions that would carry astronauts to the International Space Station and send the privately funded Polaris Dawn crew into orbit for the world’s first commercial spacewalk.

The problem cropped up during the July 11 launch of a Falcon 9 from Vandenberg Space Force Base in California. The rocket’s first stage performed as expected, went through stage separation and returned to Earth for a successful touchdown on a drone ship in the Pacific Ocean.

“Falcon 9’s second stage performed its first burn nominally,” SpaceX said in a mission recap, “however, a liquid oxygen leak developed on the second stage.”