By:
On:
In: News, RSSfeeds, Universe Today

Are We in a Giant Void? That Would Help Explain the Hubble Tension It’s assumed that our region of the Universe isn’t special, and the Hubble Tension, or mismatch of expansion rates of the Universe at different times, is happening everywhere. But what if our place is unusual, for example, if the Milky Way is inside a lower-density region of the Universe, with stronger gravity pulling material away from us in all directions? A new paper suggests we might be in a void that’s emptying out towards higher-density regions all around us. Universe Today Go to SourceRead More →

By:
On:
In: News, RSSfeeds, Universe Today

Scientists Discover Uranus Has a Dancing Partner Hidden in the darkness between Uranus and Neptune, a team of astronomers have discovered a small world locked in a million year gravitational waltz with Uranus. The asteroid enjoying this celestial dance with Uranus completes exactly three orbits for every four of the ice giant, representing the first known stable partnership of its kind in this remote region of the Solar System. The discovery proves that even in the apparent chaos of space, there are elegant mathematical relationships that have persisted, revealing new secrets about how gravitational forces sculpt the architecture of our planetary system. Universe Today GoRead More →

By:
On:
In: News, RSSfeeds, Universe Today

This is the Closest Picture Ever Taken of the Sun December 24th, 2024, NASA’s Parker Solar Probe made its closest approach to the Sun so far, coming within just 6.1 million km from the surface of the Sun. During this flyby, it captured data and images, including this incredible picture using the Wide Field Imager for Solar Probe, or WISPR. In this WISPR image, you can see the corona and solar wind, charged particles coming from the Sun, hurled across the Solar System. The next pass will happen in September. Universe Today Go to SourceRead More →

By:
On:
In: News, RSSfeeds, Universe Today

Primordial Black Hole Flybys Could Alter Exoplanet Orbits Close encounters with massive objects can alter the orbits of planets around their stars. Stellar flybys can change planetary orbits, and may be responsible for some of the rogue or free-floating planets astronomers have discovered. But stars aren’t the only massive objects out there, and new research suggests that primordial black holes may alter the orbits of exoplanets. Universe Today Go to SourceRead More →

By:
On:
In: News, RSSfeeds, Universe Today

Funding Astrobiology Challenges Can Bring Us Closer To Understanding the Origins of Life Astrobiology can be split into two very distinct fields. There’s the field that astronomers are likely more familiar with, involving large telescopes, exoplanets, and spectroscopic signals that are pored over to debate whether they show signs of life. But there is another camp, collective known as the Origins researchers that focus on developing a scientific understanding of how life originally developed on Earth. A new paper from Cole Mathis at Arizona State and Harrison B. Smith at the Institute of Science in Tokyo suggests a new path forward to tackling those challengesRead More →

By:
On:
In: News, RSSfeeds, Universe Today

Ancient Rivers in Noachis Terra Reveal Mars’ Long-Lived Wet Past In the last couple of decades, evidence has accumulated showing that ancient Mars was a warm planet with abundant water flowing across its surface. The more scientists study the planet, the more evidence they find. New research examining Mars’ Noachis Terra region adds to this evidence, showing that flowing water was once widespread across this less-often studied region. Universe Today Go to SourceRead More →

By:
On:
In: News, RSSfeeds, Universe Today

Spotting New Interstellar Comet C/2025 N1 ATLAS It’s the question of the hour. On the first day of the month July 1st, the Asteroid Terrestrial-impact Last Alert System (ATLAS) station at Río Hurtado, Chile spotted an interstellar interloper, which would receive the official designation C/2025 N1 ATLAS or 3I/ATLAS. The ‘I’ is a rare ‘interstellar’ designation, only the third such object known of after 1I/ʻOumuamua and 2/I Borisov. But can we see it? Such a spectacle as actually seeing an interstellar comet would be a true rarity to cross off your skywatching life list. Universe Today Go to SourceRead More →

By:
On:
In: News, RSSfeeds, Universe Today

Tracking Molecules In the Interstellar Medium Stars don’t form out of nothing, but tracking the gas and dust that do eventually form stars is hard. They float around the galaxy at almost absolute zero, emitting essentially no light, and generally making life difficult for astronomers. But, part of how they make life difficult is actually the key to studying them – they have “absorption lines” that detail what kind of material the light is passing through on its way to Earth. A new paper from Harvey Liszt of America’s National Radio Astronomy Observatory and Maryvonne Gerin of the Sorbonne details how tracking those absorption linesRead More →

By:
On:
In: News, RSSfeeds, Universe Today

Ancient Moon Rock Reveals Missing Chapter in Lunar History A 2.35 billion year old rock that fell from the sky in Africa is rewriting our understanding of the Moon’s past. This ancient meteorite, blasted off the lunar surface has revealed that our closest neighbor remained volcanically active for nearly a billion years longer than scientists previously knew. With its unique chemical fingerprint pointing to deep lunar origins, this rare space rock proves that sometimes the most extraordinary discoveries don’t require billion dollar missions, they literally drop into our laps, carrying secrets from space. Universe Today Go to SourceRead More →

By:
On:
In: News, RSSfeeds, Universe Today

A Small Satellite Could See a Perfect Solar Eclipse Every Month Why wait for rare solar eclipses? ESA’s Proba mission can now create an artificial solar eclipse once a day. Now, a UK-led mission could do the same trick, but using the Moon’s shadow to provide a 48-minute total eclipse once every lunar orbit (29.6 days). Named the Moon-Enabled Sun Occultation Mission (MESOM), the small spacecraft would align its orbit with the Moon, blocking the Sun perfectly, allowing observations of the solar atmosphere. Universe Today Go to SourceRead More →

By:
On:
In: arXiv

Snapshot of a new interstellar comet: 3I/ATLAS has a red and featureless spectrum Cyrielle Opitom, Colin Snodgrass, Emmanuel Jehin, Michele T. Bannister, Erica Bufanda, Sophie E. Deam, Rosemary Dorsey, Marin Ferrais, Said Hmiddouch, Matthew M. Knight, Rosita Kokotanekova, Brayden Leicester, Micha"el Marsset, Brian Murphy, Vincent Okoth, Ryan Ridden-Harper, Mathieu Vander Donckt, L’ea Ferellec, Damien Hutsemekers, Manuela Lippi, Jean Manfroid, Zouhair Benkhaldoun arXiv:2507.05226v2 Announce Type: replace Abstract: The interstellar comet 3I/ATLAS is only the third interstellar object to be discovered. Pre-perihelion measurements provide a unique opportunity to study its activity and composition, which may alter as it is heated in the coming months. We provide anRead More →

By:
On:
In: arXiv

CASCO: Cosmological and AStrophysical parameters from Cosmological simulations and Observations III. The physics behind the emergence of the golden mass scale C. Tortora, V. Busillo, N. R. Napolitano, L. V. E. Koopmans, G. Covone, S. Genel, F. Villaescusa-Navarro, M. Silvestrini arXiv:2502.13589v2 Announce Type: replace Abstract: We investigate the origin and evolution of the “golden mass” (halo mass $sim10^{12} , rm M_{odot}$, stellar mass $sim5 times 10^{10} , rm M_{odot}$), linked to peak star formation efficiency, using textsc{camels} simulations based on IllustrisTNG. Exploring a range of SN/AGN feedback strengths and cosmologies ($Omega_{rm m}, sigma_8$), we find a U-shaped relation between dark-to-stellar mass ratio and stellar mass,Read More →

By:
On:
In: arXiv

On the difficulty of capturing the distribution function of neutrinos in neutron star merger simulations Francois Foucart arXiv:2504.21822v2 Announce Type: replace Abstract: The collision of two neutron stars is a rich source of information about nuclear physics. In particular, the kilonova signal following a merger can help us elucidate the role of neutron stars in nucleosynthesis, and informs us about the properties of matter above nuclear saturation. Approximate modeling of neutrinos remains an important limitation to our ability to make predictions for these observables. Part of the problem is the fermionic nature of neutrinos. By the exclusion principle, the expected value $f_nu$ for the numberRead More →

By:
On:
In: arXiv

Protostellar Disks Fed By Dense Collapsing Gravo-Magneto-Sheetlets Yisheng Tu, Zhi-Yun Li, Ka Ho Lam, Kengo Tomida, Chun-Yen Hsu arXiv:2307.16774v3 Announce Type: replace Abstract: Stars form from the gravitational collapse of turbulent, magnetized molecular cloud cores. Our non-ideal MHD simulations reveal that the intrinsically anisotropic magnetic resistance to gravity during the core collapse naturally generates dense gravo-magneto-sheetlets within inner protostellar envelopes — disrupted versions of classical sheet-like pseudodisks. They are embedded in a magnetically dominant background, where less dense materials flow along the local magnetic field lines and accumulate in the dense sheetlets. The sheetlets, which feed the disk predominantly through its upper and lower surfaces,Read More →

By:
On:
In: arXiv

A novel approach to cosmological non-linearities as an effective fluid Leonardo Giani, Rodrigo Von Marttens, Ryan Camilleri arXiv:2410.15295v2 Announce Type: replace Abstract: We propose a two parameters extension of the flat $Lambda$CDM model to capture the impact of matter inhomogeneities on our cosmological inference. Non virialized but non-linearly evolving overdense and underdense regions, whose abundance is quantified using the Press-Schechter formalism, are collectively described by two effective perfect fluids $rho_{rm{c}},rho_{rm{v}}$ with non vanishing equation of state parameters $w_{rm{c,v}}neq 0$. These fluids are coupled to the pressureless dust, akin to an interacting DM-DE scenario. The resulting phenomenology is very rich, and could potentially address a numberRead More →

By:
On:
In: arXiv

Machine Learning Tools for the IceCube-Gen2 Optical Array Francisco Javier Vara Carbonell (for the IceCube-Gen2 Collaboration), Jonas Selter (for the IceCube-Gen2 Collaboration) arXiv:2507.07844v1 Announce Type: new Abstract: Neural networks (NNs) have a great potential for future neutrino telescopes such as IceCube-Gen2, the planned high-energy extension of the IceCube observatory. IceCube-Gen2 will feature new optical sensors with multiple photomultiplier tubes (PMTs) designed to provide omnidirectional sensitivity. Neural networks excel at handling high-dimensional problems and can naturally incorporate the increased complexity of these new sensors. Additionally, their fast inference time makes them promising candidates for handling the high event rates expected from IceCube-Gen2. This contribution presents potentialRead More →

By:
On:
In: arXiv

Synthesizing Sun-as-a-star flare spectra from high-resolution solar observations M. De Wilde, A. G. M. Pietrow, M. K. Druett, A. Pastor Yabar, J. Koza, I. Kontogiannis, O. Andriienko, A. Berlicki, A. R. Brunvoll, J. de la Cruz Rodr’iguez, J. T. Faber, R. Joshi, D. Kuridze, D. N’obrega-Siverio, L. H. M. Rouppe van der Voort, J. Ryb’ak, E. Scullion, A. M. Silva, Z. Vashalomidze, A. Vicente Ar’evalo, A. Wi’sniewska, R. Yadav, T. V. Zaqarashvili, J. Zbinden, E. S. {O}yre arXiv:2507.07967v1 Announce Type: new Abstract: Spatially resolved observations of the Sun and the astronomical sample size of stellar bodies are the respective key strengths of solar and stellarRead More →

By:
On:
In: arXiv

JWST COMPASS: A NIRSpec G395H Transmission Spectrum of the Super-Earth GJ 357 b Jea Adams Redai, Nicholas Wogan, Nicole L. Wallack, Munazza K. Alam, Artyom Aguichine, Angie Wolfgang, Hannah R. Wakeford, Johanna Teske, Nicholas Scarsdale, Sarah E. Moran, Mercedes Lopez Morales, Annabella Meech, Peter Gao, Anna Gagnebin, Natasha E. Batalha, Natalie M. Batalha, Lili Alderson arXiv:2507.07165v1 Announce Type: new Abstract: We present JWST NIRSpec/G395H transmission spectroscopy observations of GJ 357 b, a warm ($T_{mathrm{eq}} approx 525$ K) super-Earth ($1.2 mathrm{R_{oplus}} $, $1.84 mathrm{M_{oplus}} $) orbiting a nearby M3-type star, with a median precision of 18 ppm and 27 ppm in NRS1 and NRS2, respectively. TheseRead More →

By:
On:
In: arXiv

The Orbital Eccentricity-Radius Relation for Planets Orbiting M Dwarfs Sheila Sagear, Sarah Ballard, Gregory J. Gilbert, Mariangel Albornoz, Christopher Lam arXiv:2507.07169v1 Announce Type: new Abstract: The orbital eccentricity-radius relation for small planets is indicative of the predominant dynamical sculpting processes during late-stage orbital evolution. Previous studies have shown that planets orbiting Sun-like stars exhibit an eccentricity-radius trend such that larger planets have higher orbital eccentricities, and that radius gap planets may have modestly higher orbital eccentricities than planets on either side of the radius gap. In this work, we investigate the trend for a sample of smaller M dwarf stars. For a sample of 236Read More →

By:
On:
In: arXiv

Correlations between Dust Extinction Features across All Wavelength Scales: From Diffuse Interstellar Bands to R(V) Andrew K. Saydjari, Gregory M. Green arXiv:2507.07162v1 Announce Type: new Abstract: Understanding variations in the dust extinction curve is imperative for using dust as a tracer of local structure in the interstellar medium, understanding dust chemistry, and observational color corrections where dust is a nuisance parameter. However, the extinction curve is complicated and exhibits features across a wide range of wavelength scales, from narrow atomic lines and diffuse interstellar bands (“DIBs”), to intermediate-scale and very broad structures (“ISS” and “VBS”), and the overall slope of the optical extinction curve, parameterizedRead More →