Planetary Geophysics: What is it? What can it teach us about finding life beyond Earth? Universe Today has examined the importance of studying impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, and planetary atmospheres, and how these intriguing scientific disciplines can help scientists and the public better understand how we are pursuing life beyond Earth. Here, we will look inward and examine the role that planetary geophysics plays in helping scientists gain greater insight into our solar system and beyond, including the benefits and challenges, finding life beyond Earth, and how upcoming students can pursue studying planetary geophysics. So, what is planetary geophysics andRead More →

Webb Finds Hints of a Third Planet at PDS 70 The exoplanet census now stands at 5,599 confirmed discoveries in 4,163 star systems, with another 10,157 candidates awaiting confirmation. So far, the vast majority of these have been detected using indirect methods, including Transit Photometry (74.4%) and Radial Velocity measurements (19.4%). Only nineteen (or 1.2%) were detected via Direct Imaging, a method where light reflected from an exoplanet’s atmosphere or surface is used to detect and characterize it. Thanks to the latest generation of high-contrast and high-angular resolution instruments, this is starting to change. This includes the James Webb Space Telescope and its sophisticated mirrorsRead More →

This New Map of 1.3 Million Quasars Is A Powerful Tool Quasars are the brightest objects in the Universe. The most powerful ones are thousands of times more luminous than entire galaxies. They’re the visible part of a supermassive black hole (SMBH) at the center of a galaxy. The intense light comes from gas drawn toward the black hole, emitting light across several wavelengths as it heats up. But quasars are more than just bright ancient objects. They have something important to show us about the dark matter. Large galaxies have supermassive black holes at their centers. Even those only casually familiar with space knowRead More →

Improving a 1960s Plan to Explore the Giant Planets In the 1960s, NASA engineers developed a series of small lifting-body aircraft that could be dropped into the atmosphere of a giant planet, measuring the environment as they glided down. Although it would be a one-way trip to destruction, the form factor would allow a probe to glide around in different atmospheric layers, gathering data and transmitting it back to a parent satellite. An updated version of the 1960s design is being tested at NASA now, and a drop-test flight from a helicopter is scheduled for this month. “We are looking to take an idea toRead More →

Finally, an Explanation for the “String of Pearls” in Supernova 1987A Not long after the explosion of Supernova 1987a, astronomers were abuzz with predictions about how it might look in a few years. They suggested a pulsar would show up soon and many said that the expanding gas cloud would encounter earlier material ejected from the star. The collision would light up the region around the event and sparkle like diamonds. Today, astronomers look at the site of the stellar catastrophe and see an expanding, glowing ring of light. Over the years, its shape has changed to a clumpy-looking string of pearls. What’s happening toRead More →

Hubble views dwarf galaxy LEDA 4216 This NASA/ESA Hubble Space Telescope image shows LEDA 42160, a galaxy about 52 million light-years from Earth in the constellation Virgo. The dwarf galaxy is one of many forcing its way through the comparatively dense gas in the massive Virgo cluster of galaxies. The pressure exerted by this intergalactic gas, known as ram pressure, has dramatic effects on star formation in LEDA 42160. phys.org Go to SourceRead More →

The cosmic neutrino background would tell us plenty about the universe, says researcher Readers of Universe Today are probably already familiar with the concept of the cosmic microwave background (CMB). Its serendipitous discovery by a pair of radio astronomers at Bell Labs is the stuff of astronomical legend. Over the past decades, it has offered plenty of insights into the Big Bang and the origins of our universe. But there is another, less well-known background signal that could be just as revolutionary—or at least we think there is. phys.org Go to SourceRead More →

NASA is Working on Zero-Boil Off Tanks for Space Exploration No matter what mode of transportation you take for a long trip, at some point, you’ll have to refuel. For cars, this could be a simple trip to a gas station, while planes, trains, and ships have more specialized refueling services at their depots or ports. However, for spacecraft, there is currently no refueling infrastructure whatsoever. And since the fuel spacecraft use must be stored cryogenically, and the tanks the fuel is stored in are constantly subjected to the thermal radiation from the Sun, keeping enough fuel in a tank for a trip to MarsRead More →

Largest-ever map of universe’s active supermassive black holes released Astronomers have charted the largest-ever volume of the universe with a new map of active supermassive black holes living at the centers of galaxies. Called quasars, the gas-gobbling black holes are, ironically, some of the universe’s brightest objects. phys.org Go to SourceRead More →

NASA volunteers find 15 rare ‘active asteroids’ Some extraordinary asteroids have “activity”—comet-like tails or envelopes of gas and dust. NASA’s Active Asteroids project announced the discovery of activity on 15 asteroids, challenging conventional wisdom about the solar system. phys.org Go to SourceRead More →

JWST observations shed more light on the nature of a distant galaxy cluster Astronomers from the Nanjing University in China and elsewhere have performed high-resolution observations of a distant galaxy cluster known as CL J1001+0220 using the James Webb Space Telescope (JWST). The observational campaign, described in a paper published March 8 on the preprint server arXiv, yields important information regarding the nature of this cluster. phys.org Go to SourceRead More →

The Carbon Isotopic Ratio and Planet Formation Edwin A. Bergin, Arthur Bosman, Richard Teague, Jenny Calahan, Karen Willacy, L. Ilsedore Cleeves, Kamber Schwarz, Ke Zhang, Simon Bruderer arXiv:2403.09739v1 Announce Type: new Abstract: We present the first detection of 13CCH in a protoplanetary disk (TW Hya). Using observations of C2H we measure CCH/13CCH = 65 +/- 20 in gas with a CO isotopic ratio of 12CO/13CO = 21 +/- 5 (Yoshida et al. 2022a). The TW Hya disk exhibits a gas phase C/O that exceeds unity and C2H is the tracer of this excess carbon. We confirm that the TW Hya gaseous disk exhibits two separateRead More →

One-winged butterflies: mode selection for azimuthal magnetorotational instability by thermal convection A. Mishra, G. Mamatsashvili, M. Seilmayer, F. Stefani arXiv:2403.09764v1 Announce Type: new Abstract: The effects of thermal convection on turbulence in accretion discs, and particularly its interaction with the magnetorotational instability (MRI), are of significant astrophysical interest. Despite extensive theoretical and numerical studies, such interactions have not been explored experimentally. We conduct linear analysis of the azimuthal version of MRI (AMRI) in the presence of convection and compare our findings with the experimental data. We show that AMRI sets in at lower critical Hartmann numbers ($Ha$) in the presence of convection. Importantly, convection breaksRead More →

The Active Asteroids Citizen Science Program: Overview and First Results Colin Orion Chandler, Chadwick A. Trujillo, William J. Oldroyd, Jay K. Kueny, William A. Burris, Henry H. Hsieh, Jarod A. DeSpain, Nima Sedaghat, Scott S. Sheppard, Kennedy A. Farrell, David E. Trilling, Annika Gustafsson, Mark Jesus Mendoza Magbanua, Michele T. Mazzucato, Milton K. D. Bosch, Tiffany Shaw-Diaz, Virgilio Gonano, Al Lamperti, Jos’e A. da Silva Campos, Brian L. Goodwin, Ivan A. Terentev, Charles J. A. Dukes, Sam Deen arXiv:2403.09768v1 Announce Type: new Abstract: We present the Citizen Science program Active Asteroids and describe discoveries stemming from our ongoing project. Our NASA Partner program is hostedRead More →

Large Eddy Simulations of Magnetized Mergers of Black Holes and Neutron Stars Manuel R. Izquierdo, Miguel Bezares, Steven Liebling, Carlos Palenzuela arXiv:2403.09770v1 Announce Type: new Abstract: The LIGO-Virgo-Kagra collaboration has observed gravitational waves consistent with the mergers of a black hole and a neutron star, namely GW200105 and GW200115, providing evidence for such cataclysmic events. Although no electromagnetic counterpart was reported for either of these two events, under certain conditions black hole–neutron star mergers are expected to form a significant accretion disk and to produce both a short gamma ray burst and a kilonova, much as observed in the binary neutron star merger GW170817. Here,Read More →

TRANSLIENT: Detecting Transients Resulting from Point Source Motion or Astrometric Errors O. Springer, E. O. Ofek, B. Zackay, R. Konno, A. Sharon, G. Nir, A. Rubin, A. Haddad, J. Friedman, L. Schein Lubomirsky, I. Aizenberg, A. Krassilchtchikov, A. Gal-Yam arXiv:2403.09771v1 Announce Type: new Abstract: Detection of moving sources over complicated background is important for several reasons. First is measuring the astrophysical motion of the source. Second is that such motion resulting from atmospheric scintillation, color refraction, or astrophysical reasons is a major source of false alarms for image subtraction methods. We extend the Zackay, Ofek, and Gal-Yam image subtraction formalism to deal with moving sources.Read More →

[N I] 10400/10410 {AA} Lines as Possible Disk Wind Tracers in a Young Intermediate-Mass Star Haruki Katoh, Chikako Yasui, Yuji Ikeda, Naoto Kobayashi, Noriyuki Matsunaga, Sohei Kondo, Hiroaki Sameshima, Satoshi Hamano, Misaki Mizumoto, Hideyo Kawakita, Kei Fukue, Shogo Otsubo, Keiichi Takenaka arXiv:2403.09774v1 Announce Type: new Abstract: In this study, we performed high-resolution near-infrared (NIR) spectroscopy (R = 28,000; ${lambda} = 0.90$-1.35 ${mu}$m) with a high signal-to-noise ratio on HD 200775, a very young (${sim}$0.1 Myr old) and massive intermediate-mass star (a binary star with a mass of about 10 $M_{odot}$ each) with a protoplanetary disk. The obtained spectra show eight forbidden lines of three elements:Read More →

Stellar Mergers or Truly Young? Intermediate-Age Stars on Highly-Radial Orbits in the Milky Way’s Stellar Halo Danny Horta (Lucy), Yuxi (Lucy), Lu, Melissa K. Ness, Mariangela Lisanti, Adrian M. Price-Whelan arXiv:2403.09777v1 Announce Type: new Abstract: Reconstructing the mass assembly history of the Milky Way relies on obtaining detailed measurements of the properties of many stars in the Galaxy, especially in the stellar halo. One of the most constraining quantities is stellar age, as it can shed light on the accretion time and quenching of star formation in merging satellites. However, obtaining reliable age estimates for large samples of halo stars is difficult. We report publishedRead More →

Formation of Large Circumstellar Discs in Multi-scale, ideal-MHD Simulations of Magnetically Critical Pre-stellar Cores Chong-Chong He, Massimo Ricotti arXiv:2403.09779v1 Announce Type: new Abstract: The formation of circumstellar discs is a critical step in the formation of stars and planets. Magnetic fields can strongly affect the evolution of angular momentum during prestellar core collapse, potentially leading to the failure of protostellar disc formation. This phenomenon, known as the magnetic braking catastrophe, has been observed in ideal-MHD simulations. In this work, we present results from ideal-MHD simulations of circumstellar disc formation from realistic initial conditions of strongly magnetised, massive cores with masses between $30 ~{rm M}_odot$ andRead More →

Modeling JWST MIRI-MRS Observations of T Cha: Mid-IR Noble Gas Emission Tracing a Dense Disk Wind Andrew D. Sellek, Naman S. Bajaj, Ilaria Pascucci, Cathie J. Clarke, Richard Alexander, Chengyan Xie, Giulia Ballabio, Dingshan Deng, Uma Gorti, Andras Gaspar, Jane Morrison arXiv:2403.09780v1 Announce Type: new Abstract: [Ne II] 12.81 $mumathrm{m}$ emission is a well-used tracer of protoplanetary disk winds due to its blueshifted line profile. MIRI-MRS recently observed T Cha, detecting this line along with lines of [Ne III], [Ar II] and [Ar III], with the [Ne II] and [Ne III] lines found to be extended while the [Ar II] was not. In this complementaryRead More →