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A young gas giant and hidden substructures in a protoplanetary disk

Planetary systems - Thu, 17/07/2025 - 10:35
arXiv:2507.11612v1 Announce Type: new Abstract: The detection of planets in protoplanetary disks has proven to be extremely challenging. In contrast, rings and gaps, usually attributed to planet-disk interactions, have been found in virtually every large protoplanetary (Class II) disk observed at 0.9-1.3 mm with sufficient spatial resolution (5 au). The nearby disk around MP Mus (PDS 66) stands as an exception to this rule, and its advanced age (7-10 Myr) is particularly difficult to reconcile with its apparent lack of substructures. Despite the disk's smooth appearance, Gaia data of MP Mus show a significant proper motion anomaly, signalling the presence of a companion. Here we present ALMA 3 mm observations of the system with comparable high spatial resolution to previous 1.3 mm data. The new observations pierce deeper into the disk midplane and reveal an inner cavity (<3 au) and a ring at 10 au. The disk structure inferred from ALMA observations narrows down the properties of the companion to a gas giant orbiting at 1-3 au, and hydrodynamic simulations further confirm that such a planet can produce the observed cavity. These independent pieces of evidence constitute an indirect but compelling detection of an exoplanet within a protoplanetary disk using Gaia astrometry. MP Mus is the first system in which undetected substructures are revealed thanks to the lower optical depths at longer wavelengths, suggesting that rings and gaps are even more abundant than what is currently believed.

Star flares when an orbiting planet gets too close

Astronomy News - Thu, 17/07/2025 - 10:11

Nature, Published online: 16 July 2025; doi:10.1038/d41586-025-02201-w

A planet that orbits closely to its young host star has been observed to induce large magnetic eruptions on the star. These flares might rapidly blow away the planet’s atmosphere, leaving behind a dense core within a few hundred million years.

Refractory solid condensation detected in an embedded protoplanetary disk

Astronomy News - Thu, 17/07/2025 - 10:11

Nature, Published online: 16 July 2025; doi:10.1038/s41586-025-09163-z

Observations at infrared and millimetre wavelengths of the young protostar HOPS-315 show a gaseous disk captured at the point at which solids are first starting to condense, the t = 0 for planet formation.

Birth of a solar system caught ‘on camera’ for first time

Astronomy News - Thu, 17/07/2025 - 10:10

Nature, Published online: 16 July 2025; doi:10.1038/d41586-025-02245-y

Astronomers get rare glimpse of earliest stages of planet formation around a baby star.

The origin of the oldest solid objects in the Solar System

Astronomy News - Thu, 17/07/2025 - 10:10

Nature, Published online: 16 July 2025; doi:10.1038/d41586-025-02058-z

Observations of a young star offer a glimpse of the high-temperature conditions that shaped rock formation in the early Solar System.

NASA’s Chandra Finds Baby Exoplanet is Shrinking

Astronomy News - Thu, 17/07/2025 - 10:09
X-ray: NASA/CXC/RIT/A. Varga et al.; Illustration: NASA/CXC/SAO/M. Weiss; Image Processing: NASA/CXC/SAO/N. Wolk

star is unleashing a barrage of X-rays that is causing a closely-orbiting, young planet to wither away an astonishing rate, according to a new study using data from NASA’s Chandra X-ray Observatory and described in our latest press release. A team of researchers has determined that this planet will go from the size of Jupiter down to a small, barren world.

This graphic provides a visual representation of what astronomers think is happening around the star (known as TOI 1227) and a planet that is orbiting it at a fraction the distance between Mercury and the Sun. This “baby” planet, called TOI 1227 b, is just about 8 million years old, about a thousand times younger than our Sun. The main panel is an artist’s concept that shows the Jupiter-sized planet (lower left) around TOI 1227, which is a faint red star. Powerful X-rays from the star’s surface are tearing away the atmosphere of the planet, represented by the blue tail. The star’s X-rays may eventually completely remove the atmosphere.

The team used new Chandra data — seen in the inset — to measure the amounts of X-rays from TOI 1227 that are striking the planet. Using computer models of the effects of these X-rays, they concluded they will have a transformative effect, rapidly stripping away the planet’s atmosphere. They estimate that the planet is losing a mass equivalent to a full Earth’s atmosphere about every 200 years.

The researchers used different sets of data to estimate the age of TOI 1227 b. One method exploits measurements of how TOI 1227 b’s host star moves through space in comparison to nearby populations of stars with known ages. A second method compared the brightness and surface temperature of the star with theoretical models of evolving stars. The very young age of TOI 1227 b makes it the second youngest planet ever to be observed passing in front of its host star (a so-called transit). Previously the planet had been estimated by others to be about 11 million years old.

Of all the exoplanets astronomers have found with ages less than 50 million years, TOI 1227 b stands out for having the longest year and the host planet with the lowest mass. These properties, and the high dose of X-rays it is receiving, make it an outstanding target for future observations.

A paper describing these results has been accepted publication in The Astrophysical Journal and a preprint is available here. The authors of the paper are Attila Varga (Rochester Institute of Technology), Joel Kastner (Rochester Institute of Technology), Alexander Binks (University of Tubingen, Germany), Hans Moritz Guenther (Massachusetts Institute of Technology), and Simon J. Murphy (University of New South Wales Canberra in Australia).

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Read more from NASA’s Chandra X-ray Observatory

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

This release features an artist’s illustration of a Jupiter-sized planet closely orbiting a faint red star. An inset image, showing the star in X-ray light from Chandra, is superimposed on top of the illustration at our upper left corner.

At our upper right, the red star is illustrated as a ball made of intense fire. The planet, slightly smaller than the star, is shown at our lower left. Powerful X-rays from the star are tearing away the atmosphere of the planet, causing wisps of material to flow away from the planet’s surface in the opposite direction from the star. This gives the planet a slight resemblance to a comet, complete with a tail.

X-ray data from Chandra, presented in the inset image, shows the star as a small purple orb on a black background. Astronomers used the Chandra data to measure the amount of X-rays striking the planet from the star. They estimate that the planet is losing a mass equivalent to a full Earth’s atmosphere about every 200 years, causing it to ultimately shrink from the size of Jupiter down to a small, barren world.

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Corinne Beckinger
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
corinne.m.beckinger@nasa.gov

Share Details Last Updated Jul 16, 2025 EditorLee MohonContactCorinne M. Beckingercorinne.m.beckinger@nasa.gov Related Terms Explore More 3 min read NASA Citizen Science and Your Career: Stories of Exoplanet Watch Volunteers

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On Hot Jupiters and Stellar Clustering: The Role of Host Star Demographics

Recent IoA Publications - Wed, 16/07/2025 - 11:41
arXiv:2507.11225v1 Announce Type: new Abstract: The variation in hot Jupiter (HJ) occurrence across stellar environments holds clues as to the dominant formation channels of these extreme planets. Recent studies suggest HJ hosts preferentially reside in regions of high phase space density, possibly reflecting natal environmental conditions. These regions are kinematically cold (|v| < 40 km/s), prompting the alternative hypothesis that the correlation reflects an age bias: planetary systems in overdensities are systematically younger and therefore less likely to have undergone tidal inspiral and destruction. We test whether the apparent excess of HJs in phase space overdensities arises from differences in intrinsic host properties -- mass, metallicity, age -- which may correlate with phase space density or whether there is evidence for an additional environmental effect. We derive homogeneous estimates for the mass, metallicity, and age of planet-hosting stars using 2MASS and Gaia DR3 photometry, parallaxes, and self-consistent spectroscopic and spectrophotometric observables. In a sample of 2265 confirmed exoplanet hosts, we find a significant relative excess of HJs orbiting stars in overdense regions. However, we also find that overdensities preferentially host younger, more massive, and more metal-rich stars compared to underdensities. After correcting for these differences, either by detrending the phase space density against age or by matching host properties across subsamples, we find no significant differences in the HJ populations between over- and underdense regions. Our results suggest that the previously reported correlation between HJ occurrence and phase space density is driven by underlying differences in host star demographics rather than an intrinsic environmental effect.

On Hot Jupiters and Stellar Clustering: The Role of Host Star Demographics

Stars and stellar evolution - Wed, 16/07/2025 - 11:41
arXiv:2507.11225v1 Announce Type: new Abstract: The variation in hot Jupiter (HJ) occurrence across stellar environments holds clues as to the dominant formation channels of these extreme planets. Recent studies suggest HJ hosts preferentially reside in regions of high phase space density, possibly reflecting natal environmental conditions. These regions are kinematically cold (|v| < 40 km/s), prompting the alternative hypothesis that the correlation reflects an age bias: planetary systems in overdensities are systematically younger and therefore less likely to have undergone tidal inspiral and destruction. We test whether the apparent excess of HJs in phase space overdensities arises from differences in intrinsic host properties -- mass, metallicity, age -- which may correlate with phase space density or whether there is evidence for an additional environmental effect. We derive homogeneous estimates for the mass, metallicity, and age of planet-hosting stars using 2MASS and Gaia DR3 photometry, parallaxes, and self-consistent spectroscopic and spectrophotometric observables. In a sample of 2265 confirmed exoplanet hosts, we find a significant relative excess of HJs orbiting stars in overdense regions. However, we also find that overdensities preferentially host younger, more massive, and more metal-rich stars compared to underdensities. After correcting for these differences, either by detrending the phase space density against age or by matching host properties across subsamples, we find no significant differences in the HJ populations between over- and underdense regions. Our results suggest that the previously reported correlation between HJ occurrence and phase space density is driven by underlying differences in host star demographics rather than an intrinsic environmental effect.

On Hot Jupiters and Stellar Clustering: The Role of Host Star Demographics

Planetary systems - Wed, 16/07/2025 - 11:41
arXiv:2507.11225v1 Announce Type: new Abstract: The variation in hot Jupiter (HJ) occurrence across stellar environments holds clues as to the dominant formation channels of these extreme planets. Recent studies suggest HJ hosts preferentially reside in regions of high phase space density, possibly reflecting natal environmental conditions. These regions are kinematically cold (|v| < 40 km/s), prompting the alternative hypothesis that the correlation reflects an age bias: planetary systems in overdensities are systematically younger and therefore less likely to have undergone tidal inspiral and destruction. We test whether the apparent excess of HJs in phase space overdensities arises from differences in intrinsic host properties -- mass, metallicity, age -- which may correlate with phase space density or whether there is evidence for an additional environmental effect. We derive homogeneous estimates for the mass, metallicity, and age of planet-hosting stars using 2MASS and Gaia DR3 photometry, parallaxes, and self-consistent spectroscopic and spectrophotometric observables. In a sample of 2265 confirmed exoplanet hosts, we find a significant relative excess of HJs orbiting stars in overdense regions. However, we also find that overdensities preferentially host younger, more massive, and more metal-rich stars compared to underdensities. After correcting for these differences, either by detrending the phase space density against age or by matching host properties across subsamples, we find no significant differences in the HJ populations between over- and underdense regions. Our results suggest that the previously reported correlation between HJ occurrence and phase space density is driven by underlying differences in host star demographics rather than an intrinsic environmental effect.

Euclid VI. NISP-P optical ghosts

Instrumentation and Surveys - Wed, 16/07/2025 - 11:37
arXiv:2507.11072v1 Announce Type: new Abstract: The Near-Infrared Spectrometer and Photometer (NISP) onboard Euclid includes several optical elements in its path, which introduce artefacts into the data from non-nominal light paths. To ensure uncontaminated source photometry, these artefacts must be accurately accounted for. This paper focuses on two specific optical features in NISP's photometric data (NISP-P): ghosts caused by the telescope's dichroic beamsplitter, and the bandpass filters within the NISP fore-optics. Both ghost types exhibit a characteristic morphology and are offset from the originating stars. The offsets are well modelled using 2D polynomials, with only stars brighter than approximately 10 magnitudes in each filter producing significant ghost contributions. The masking radii for these ghosts depend on both the source-star brightness and the filter wavelength, ranging from 20 to 40 pixels. We present the final relations and models used in the near-infrared (NIR) data pipeline to mask these ghosts for Euclid's Quick Data Release (Q1).

Euclid VI. NISP-P optical ghosts

Recent IoA Publications - Wed, 16/07/2025 - 11:37
arXiv:2507.11072v1 Announce Type: new Abstract: The Near-Infrared Spectrometer and Photometer (NISP) onboard Euclid includes several optical elements in its path, which introduce artefacts into the data from non-nominal light paths. To ensure uncontaminated source photometry, these artefacts must be accurately accounted for. This paper focuses on two specific optical features in NISP's photometric data (NISP-P): ghosts caused by the telescope's dichroic beamsplitter, and the bandpass filters within the NISP fore-optics. Both ghost types exhibit a characteristic morphology and are offset from the originating stars. The offsets are well modelled using 2D polynomials, with only stars brighter than approximately 10 magnitudes in each filter producing significant ghost contributions. The masking radii for these ghosts depend on both the source-star brightness and the filter wavelength, ranging from 20 to 40 pixels. We present the final relations and models used in the near-infrared (NIR) data pipeline to mask these ghosts for Euclid's Quick Data Release (Q1).

Hubble Observations Give “Missing” Globular Cluster Time to Shine

Astronomy News - Wed, 16/07/2025 - 10:24
This NASA Hubble Space Telescope image features a dense and dazzling array of blazing stars that form globular cluster ESO 591-12.NASA, ESA, and D. Massari (INAF — Osservatorio di Astrofisica e Scienza dello Spazio); Processing: Gladys Kober (NASA/Catholic University of America)

A previously unexplored globular cluster glitters with multicolored stars in this NASA Hubble Space Telescope image. Globular clusters like this one, called ESO 591-12 or Palomar 8, are spherical collections of tens of thousands to millions of stars tightly bound together by gravity. Globular clusters generally form early in the galaxies’ histories in regions rich in gas and dust. Since the stars form from the same cloud of gas as it collapses, they typically hover around the same age. Strewn across this image of ESO 591-12 are a number of red and blue stars. The colors indicate their temperatures; red stars are cooler, while the blue stars are hotter.

Hubble captured the data used to create this image of ESO 591-12 as part of a study intended to resolve individual stars of the entire globular cluster system of the Milky Way. Hubble revolutionized the study of globular clusters since earthbound telescopes are unable to distinguish individual stars in the compact clusters. The study is part of the Hubble Missing Globular Clusters Survey, which targets 34 confirmed Milky Way globular clusters that Hubble has yet to observe.

The program aims to provide complete observations of ages and distances for all of the Milky Way’s globular clusters and investigate fundamental properties of still-unexplored clusters in the galactic bulge or halo. The observations will provide key information on the early stages of our galaxy, when globular clusters formed.

Image credit: NASA, ESA, and D. Massari (INAF — Osservatorio di Astrofisica e Scienza dello Spazio); Processing: Gladys Kober (NASA/Catholic University of America)

Monster black hole merger is biggest ever seen

Astronomy News - Wed, 16/07/2025 - 10:23

Nature, Published online: 15 July 2025; doi:10.1038/d41586-025-02212-7

Gravitational-wave detector LIGO spots fast-spinning ‘forbidden’ black holes that challenge physics models.

The mysterious missing ingredient in the highest-energy cosmic rays

Astronomy News - Wed, 16/07/2025 - 10:22

Nature, Published online: 15 July 2025; doi:10.1038/d41586-025-02227-0

Data from a South Pole observatory show that the fraction of protons in ultrahigh-energy cosmic rays is lower than expected.

Water might be even more important for alien life than we thought

Astronomy News - Wed, 16/07/2025 - 10:22

Without enough liquid water on the surface, a planet's atmosphere can become choked with carbon dioxide, raising temperatures to a level beyond what is survivable for all known life

Mon 21 Jul 16:00: Bayesian Component Separation for DESI LAE Automated Spectroscopic Redshifts and Photometric Targeting

IoA Institute of Astronomy Talk Lists - Wed, 16/07/2025 - 01:00
Bayesian Component Separation for DESI LAE Automated Spectroscopic Redshifts and Photometric Targeting

Lyman Alpha Emitters (LAEs) are valuable high-redshift cosmological probes traditionally targeted with specialized narrow-band photometric surveys. In ground-based spectroscopy, it can be difficult to distinguish the sharp LAE peak from residual sky emission lines, leading to misclassified redshifts. We present a Bayesian spectral component separation technique to automatically determine spectroscopic redshifts for LAEs while marginalizing over sky residuals. We use visually inspected DESI (Dark Energy Spectroscopic Instrument) LAE targets to create a data-driven prior and can determine redshift by jointly inferring sky residual, LAE , and residual components for each individual spectrum. We demonstrate this method on 910 photometrically targeted z = 2-4 DESI LAE candidate spectra and determine their redshifts with >90% accuracy compared to visually inspected redshifts. Using the chi-squared value from our pipeline as a proxy for detection confidence, we then explore potential survey design choices and implications for targeting LAEs with medium-band photometry. This method allows for scalability and accuracy in determining spectroscopic redshifts in DESI and the results provide recommendations for LAE targeting in anticipation of future high-redshift spectroscopic surveys, such as DESI -2.

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The HOSTS Survey: Suspected variable dust emission and constraints on companions around {\theta} Boo

Planetary systems - Tue, 15/07/2025 - 11:17
arXiv:2505.07585v2 Announce Type: replace Abstract: During the HOSTS survey by the LBTI, an excess emission from the main sequence star {\theta} Boo (F7V spectral type, 14.5pc distance) was observed. This excess indicates the presence of exozodiacal dust near the habitable zone (HZ) of the star. Previous observations from Spitzer and Herschel showed no sign of outer cold dust within their respective detection limits. Additional nulling and high-contrast AO observations were taken to spatially constrain the dust distribution, search for variability, and directly image potential companions in the system. This study presents the results of these observations and provides an interpretation of the inner system's architecture. The star was observed using the LBTI's N'-band nulling mode during three epochs in 2017, 2018, and 2023. The dust distribution is modeled and constrained for each epoch using the standard LBTI nulling pipeline, assuming a vertically thin disk with a face-on inclination. In addition, high-contrast AO observations are performed in the L'-band and H-band to constrain the presence of substellar companions around the star. Several solutions are found for the dust distribution, and for each epoch. However, the LBTI nulling observations are not able to discriminate between them. Using the upper limits from previous observations, we constrain the representative size of the dust grains around 3-5$\mu$m. A tentative increase in dust brightness is also measured at the Earth-equivalent insolation distance between 2017 and 2023. Several options are considered to explain the origin of the observed dust and its variability, but no clear sources could be identified from the current observations. Partly because our high-contrast AO observations could only constrain the presence of companions down to $11M_\text{Jup}$ at 1.3" separation.

The HOSTS Survey: Suspected variable dust emission and constraints on companions around {\theta} Boo

Stars and stellar evolution - Tue, 15/07/2025 - 11:17
arXiv:2505.07585v2 Announce Type: replace Abstract: During the HOSTS survey by the LBTI, an excess emission from the main sequence star {\theta} Boo (F7V spectral type, 14.5pc distance) was observed. This excess indicates the presence of exozodiacal dust near the habitable zone (HZ) of the star. Previous observations from Spitzer and Herschel showed no sign of outer cold dust within their respective detection limits. Additional nulling and high-contrast AO observations were taken to spatially constrain the dust distribution, search for variability, and directly image potential companions in the system. This study presents the results of these observations and provides an interpretation of the inner system's architecture. The star was observed using the LBTI's N'-band nulling mode during three epochs in 2017, 2018, and 2023. The dust distribution is modeled and constrained for each epoch using the standard LBTI nulling pipeline, assuming a vertically thin disk with a face-on inclination. In addition, high-contrast AO observations are performed in the L'-band and H-band to constrain the presence of substellar companions around the star. Several solutions are found for the dust distribution, and for each epoch. However, the LBTI nulling observations are not able to discriminate between them. Using the upper limits from previous observations, we constrain the representative size of the dust grains around 3-5$\mu$m. A tentative increase in dust brightness is also measured at the Earth-equivalent insolation distance between 2017 and 2023. Several options are considered to explain the origin of the observed dust and its variability, but no clear sources could be identified from the current observations. Partly because our high-contrast AO observations could only constrain the presence of companions down to $11M_\text{Jup}$ at 1.3" separation.

The HOSTS Survey: Suspected variable dust emission and constraints on companions around {\theta} Boo

Recent IoA Publications - Tue, 15/07/2025 - 11:17
arXiv:2505.07585v2 Announce Type: replace Abstract: During the HOSTS survey by the LBTI, an excess emission from the main sequence star {\theta} Boo (F7V spectral type, 14.5pc distance) was observed. This excess indicates the presence of exozodiacal dust near the habitable zone (HZ) of the star. Previous observations from Spitzer and Herschel showed no sign of outer cold dust within their respective detection limits. Additional nulling and high-contrast AO observations were taken to spatially constrain the dust distribution, search for variability, and directly image potential companions in the system. This study presents the results of these observations and provides an interpretation of the inner system's architecture. The star was observed using the LBTI's N'-band nulling mode during three epochs in 2017, 2018, and 2023. The dust distribution is modeled and constrained for each epoch using the standard LBTI nulling pipeline, assuming a vertically thin disk with a face-on inclination. In addition, high-contrast AO observations are performed in the L'-band and H-band to constrain the presence of substellar companions around the star. Several solutions are found for the dust distribution, and for each epoch. However, the LBTI nulling observations are not able to discriminate between them. Using the upper limits from previous observations, we constrain the representative size of the dust grains around 3-5$\mu$m. A tentative increase in dust brightness is also measured at the Earth-equivalent insolation distance between 2017 and 2023. Several options are considered to explain the origin of the observed dust and its variability, but no clear sources could be identified from the current observations. Partly because our high-contrast AO observations could only constrain the presence of companions down to $11M_\text{Jup}$ at 1.3" separation.