Spacecraft films first view of the Sun's south pole
'Impossible' particle that hit Earth may have been dark matter
These images are the first time we have seen the sun's south pole
Tue 17 Jun 13:00: Exoplanet Demographics: A Journey Through Space and Time
Exoplanet demographic surveys provide a unique window into planet formation and evolution. In this talk, I will showcase three distinct features in the exoplanet population and offer theoretical interpretation of the physical mechanisms that sculpt them. I will first highlight what recent measurements extending the exoplanetary census beyond the solar neighborhood can tell us about how planet formation has evolved over cosmic time. Second, I will explore the origins of “desert dweller” planets that reside deep in the “sub-Jovian desert” (2 < Rp < 10 R_Earth, periods < 3 days), a region sparsely populated but no longer empty thanks to recent surveys. I will show that “desert dwellers” may serve as laboratories to study the fate of hot Jupiters and the interiors of giant planets in exquisite detail. Lastly, I will discuss the role atmospheric photoevaporation plays in carving the orbital period distribution of puffy, gas-rich sub-Saturns; in this picture, the sub-Saturn orbital period distribution can be leveraged to estimate a fundamental property of the planet population – the core mass function of gas-rich planets. I will outline the observational implications of our theoretical work throughout the talk.
- Speaker: Timothy Hallatt (MIT)
- Tuesday 17 June 2025, 13:00-14:00
- Venue: Ryle seminar room + ONLINE - Details to be sent by email.
- Series: Exoplanet Seminars; organiser: Dr Dolev Bashi.
Euclid preparation: The NISP spectroscopy channel, on ground performance and calibration
Euclid preparation: The NISP spectroscopy channel, on ground performance and calibration
Fri 13 Jun 13:00: Constraining Inflation with Numerical Relativity
Cosmic inflation is the leading paradigm for describing the early universe, addressing fundamental issues such as the horizon and flatness problems. However, a key unresolved question is the nature of its initial conditions. In this talk, I will discuss how numerical relativity helps studying inflationary spacetimes with inhomogeneous initial conditions, particularly in the presence of strong gravitational effects from large inhomogeneities. Numerical simulations allow us to map out the phase space of initial conditions that lead to sufficient duration of slow roll inflation versus those that do not. The results strongly depend on the inflationary model, with a rule of thumb that the models with near- or super-Planckian characteristic scales are more robust to matter and geometric inhomogeneities than those with sub-Planckian scales. We mainly focus on the study of α-attractor models and our simulation results allow us to find a lower bound on the tensor-to-scalar ratio r.
- Speaker: Panos Giannadakis, Queen Mary University of London
- Friday 13 June 2025, 13:00-14:00
- Venue: Potter room/Zoom.
- Series: DAMTP Friday GR Seminar; organiser: Xi Tong.
NASA’s CODEX Captures Unique Views of Sun’s Outer Atmosphere
- NASA’s CODEX investigation captured images of the Sun’s outer atmosphere, the corona, showcasing new aspects of its gusty, uneven flow.
- The CODEX instrument, located on the International Space Station, is a coronagraph — a scientific tool that creates an artificial eclipse with physical disks — that measures the speed and temperature of solar wind using special filters.
- These first-of-their-kind measurements will help scientists improve models of space weather and better understand the Sun’s impact on Earth.
Scientists analyzing data from NASA’s CODEX (Coronal Diagnostic Experiment) investigation have successfully evaluated the instrument’s first images, revealing the speed and temperature of material flowing out from the Sun. These images, shared at a press event Tuesday at the American Astronomical Society meeting in Anchorage, Alaska, illustrate the Sun’s outer atmosphere, or corona, is not a homogenous, steady flow of material, but an area with sputtering gusts of hot plasma. These images will help scientists improve their understanding of how the Sun impacts Earth and our technology in space.
“We really never had the ability to do this kind of science before,” said Jeffrey Newmark, a heliophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the principal investigator for CODEX. “The right kind of filters, the right size instrumentation — all the right things fell into place. These are brand new observations that have never been seen before, and we think there’s a lot of really interesting science to be done with it.”
The Sun continuously radiates material in the form of the solar wind. The Sun’s magnetic field shapes this material, sometimes creating flowing, ray-like formations called coronal streamers. In this view from NASA’s CODEX instrument, large dark spots block much of the bright light from the Sun. Blocking this light allows the instrument’s sensitive equipment to capture the faint light of the Sun’s outer atmosphere. NASA/KASI/INAF/CODEX
NASA’s CODEX is a solar coronagraph, an instrument often employed to study the Sun’s faint corona, or outer atmosphere, by blocking the bright face of the Sun. The instrument, which is installed on the International Space Station, creates artificial eclipses using a series of circular pieces of material called occulting disks at the end of a long telescope-like tube. The occulting disks are about the size of a tennis ball and are held in place by three metal arms.
Scientists often use coronagraphs to study visible light from the corona, revealing dynamic features, such as solar storms, that shape the weather in space, potentially impacting Earth and beyond.
NASA missions use coronagraphs to study the Sun in various ways, but that doesn’t mean they all see the same thing. Coronagraphs on the joint NASA-ESA Solar and Heliospheric Observatory (SOHO) mission look at visible light from the solar corona with both a wide field of view and a smaller one. The CODEX instrument’s field of view is somewhere in the middle, but looks at blue light to understand temperature and speed variations in the background solar wind.
In this composite image of overlapping solar observations, the center and left panels show the field-of-view coverage of the different coronagraphs with overlays and are labeled with observation ranges in solar radii. The third panel shows a zoomed-in, color-coded portion of the larger CODEX image. It highlights the temperature ratios in that portion of the solar corona using CODEX 405.0 and 393.5 nm filters. NASA/ESA/SOHO/KASI/INAF/CODEX
“The CODEX instrument is doing something new,” said Newmark. “Previous coronagraph experiments have measured the density of material in the corona, but CODEX is measuring the temperature and speed of material in the slowly varying solar wind flowing out from the Sun.”
These new measurements allow scientists to better characterize the energy at the source of the solar wind.
The CODEX instrument uses four narrow-band filters — two for temperature and two for speed — to capture solar wind data. “By comparing the brightness of the images in each of these filters, we can tell the temperature and speed of the coronal solar wind,” said Newmark.
Understanding the speed and temperature of the solar wind helps scientists build a more accurate picture of the Sun, which is necessary for modeling and predicting the Sun’s behaviors.
“The CODEX instrument will impact space weather modeling by providing constraints for modelers to use in the future,” said Newmark. “We’re excited for what’s to come.”
by NASA Science Editorial Team
NASA’s Goddard Space Flight Center, Greenbelt, Md
CODEX is a collaboration between NASA Goddard Space Flight Center and the Korea Astronomy and Space Science Institute (KASI) with additional contribution from Italy’s National Institute for Astrophysics (INAF).
Share Details Last Updated Jun 10, 2025 Related TermsSilicate clouds and a circumplanetary disk in the YSES-1 exoplanet system
Nature, Published online: 10 June 2025; doi:10.1038/s41586-025-09174-w
Silicate clouds and a circumplanetary disk in the YSES-1 exoplanet systemMon 16 Jun 13:00: A short history of KiDS cosmic shear measurements - a.k.a. Euclid from the ground
In this seminar, I will give a historical overview of the cosmic shear measurements conducted with the Kilo-Degree Survey (KiDS) and their cosmological implications. I will focus on the progress in methodology and systematic error control that has been achieved over the past decade, with a particular focus on the observational problems that were solved to greatly increase the robustness of these analyses. I will present the final KiDS-Legacy results and highlight the lessons learned from KiDS that are most relevant for Euclid.
- Speaker: Hendrik Hildebrandt (Ruhr University Bochum)
- Monday 16 June 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Louis Legrand.
Constraints on cosmology and baryonic feedback with joint analysis of Dark Energy Survey Year 3 lensing data and ACT DR6 thermal Sunyaev-Zel'dovich effect observations
Constraints on cosmology and baryonic feedback with joint analysis of Dark Energy Survey Year 3 lensing data and ACT DR6 thermal Sunyaev-Zel'dovich effect observations
Impact of redshift distribution uncertainties on Lyman-break galaxy cosmological parameter inference
Impact of redshift distribution uncertainties on Lyman-break galaxy cosmological parameter inference
Thu 12 Jun 16:00: Magnetic fields of neutron stars: simulations and observations
Neutron stars are the largest and the strongest magnets in the Universe. Their typical radius is around 10 km and their magnetic fields could reach values of 1e15 G. Structurally, the outer 1 km shell of a neutron star is its solid crust, while the inner part is its core. Magnetic fields shape observational properties of isolated and accreting neutron stars. Strong magnetic fields play the crucial role in explaining transient and persistent X-ray emission from Anomalous X-ray Pulsars and Soft Gamma Repeaters jointly known as magnetars. Magnetic fields are not constant and expected to evolve over time. In the last years, a significant progress was made in modelling magneto-thermal evolution of neutron star crust. Ohmic decay and Hall evolution explains multiple magnetar properties. In this colloquium, I summarise the main observational constrains currently available on magnetic fields of neutron stars and confront them with state-of-art numerical simulations. I will explain how current and future observations help us to learn more about magnetic field evolution and its structure. I also explain how the neutron star core can be modelled and show preliminary results for field evolution in the core.
- Speaker: Andrei Igoshev, Newcastle University
- Thursday 12 June 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Mor Rozner.
Thu 12 Jun 16:00: Magnetic fields of neutron stars: simulations and observations
Neutron stars are the largest and the strongest magnets in the Universe. Their typical radius is around 10 km and their magnetic fields could reach values of 1e15 G. Structurally, the outer 1 km shell of a neutron star is its solid crust, while the inner part is its core. Magnetic fields shape observational properties of isolated and accreting neutron stars. Strong magnetic fields play the crucial role in explaining transient and persistent X-ray emission from Anomalous X-ray Pulsars and Soft Gamma Repeaters jointly known as magnetars. Magnetic fields are not constant and expected to evolve over time. In the last years, a significant progress was made in modelling magneto-thermal evolution of neutron star crust. Ohmic decay and Hall evolution explains multiple magnetar properties. In this colloquium, I summarise the main observational constrains currently available on magnetic fields of neutron stars and confront them with state-of-art numerical simulations. I will explain how current and future observations help us to learn more about magnetic field evolution and its structure. I also explain how the neutron star core can be modelled and show preliminary results for field evolution in the core.
- Speaker: Andrei Igoshev, Newcastle University
- Thursday 12 June 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Mor Rozner.
NASA’s Chandra Sees Surprisingly Strong Black Hole Jet at Cosmic “Noon”
A black hole has blasted out a surprisingly powerful jet in the distant universe, according to a new study from NASA’s Chandra X-ray Observatory and discussed in our latest press release. This jet exists early enough in the cosmos that it is being illuminated by the leftover glow from the big bang itself.
Astronomers used Chandra and the Karl G. Jansky Very Large Array (VLA) to study this black hole and its jet at a period they call “cosmic noon,” which occurred about three billion years after the universe began. During this time most galaxies and supermassive black holes were growing faster than at any other time during the history of the universe.
The main graphic is an artist’s illustration showing material in a disk that is falling towards a supermassive black hole. A jet is blasting away from the black hole towards the upper right, as Chandra detected in the new study. The black hole is located 11.6 billion light-years from Earth when the cosmic microwave background (CMB), the leftover glow from the big bang, was much denser than it is now. As the electrons in the jets fly away from the black hole, they move through the sea of CMB radiation and collide with microwave photons. These collisions boost the energy of the photons up into the X-ray band (purple and white), allowing them to be detected by Chandra even at this great distance, which is shown in the inset.
Researchers, in fact, identified and then confirmed the existence of two different black holes with jets over 300,000 light-years long. The two black holes are 11.6 billion and 11.7 billion light-years away from Earth, respectively. Particles in one jet are moving at between 95% and 99% of the speed of light (called J1405+0415) and in the other at between 92% and 98% of the speed of light (J1610+1811). The jet from J1610+1811 is remarkably powerful, carrying roughly half as much energy as the intense light from hot gas orbiting the black hole.
The team was able to detect these jets despite their great distances and small separation from the bright, growing supermassive black holes — known as “quasars” — because of Chandra’s sharp X-ray vision, and because the CMB was much denser then than it is now, enhancing the energy boost described above.
When quasar jets approach the speed of light, Einstein’s theory of special relativity creates a dramatic brightening effect. Jets aimed toward Earth appear much brighter than those pointed away. The same brightness astronomers observe can come from vastly different combinations of speed and viewing angle. A jet racing at near-light speed but angled away from us can appear just as bright as a slower jet pointed directly at Earth.
The researchers developed a novel statistical method that finally cracked this challenge of separating effects of speed and of viewing angle. Their approach recognizes a fundamental bias: astronomers are more likely to discover jets pointed toward Earth simply because relativistic effects make them appear brightest. They incorporated this bias using a modified probability distribution, which accounts for how jets oriented at different angles are detected in surveys.
Their method works by first using the physics of how jet particles scatter the CMB to determine the relationship between jet speed and viewing angle. Then, instead of assuming all angles are equally likely, they apply the relativistic selection effect: jets beamed toward us (smaller angles) are overrepresented in our catalogs. By running ten thousand simulations that match this biased distribution to their physical model, they could finally determine the most probable viewing angles: about 9 degrees for J1405+0415 and 11 degrees for J1610+1811.
These results were presented by Jaya Maithil (Center for Astrophysics | Harvard & Smithsonian) at the 246th meeting of the American Astronomical Society in Anchorage, AK, and are also being published in The Astrophysical Journal. A preprint is available here. 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 ObservatoryLearn more about the Chandra X-ray Observatory and its mission here:
Visual Description
This release is supported by an artist’s illustration of a jet blasting away from a supermassive black hole.
The black hole sits near the center of the illustration. It resembles a black marble with a fine yellow outline. Surrounding the black hole is a swirling disk, resembling a dinner plate tilted to face our upper right. This disk comprises concentric rings of fiery swirls, dark orange near the outer edge, and bright yellow near the core.
Shooting out of the black hole are two streaky beams of silver and pale violet. One bright beam shoots up toward our upper right, and a second somewhat dimmer beam shoots in the opposite direction, down toward our lower left. These beams are encircled by long, fine, corkscrewing lines that resemble stretched springs.
This black hole is located 11.6 billion light-years from Earth, much earlier in the history of the universe. Near this black hole, the leftover glow from the big bang, known as the cosmic microwave background or CMB, is much denser than it is now. As the electrons in the jets blast away from the black hole, they move through the sea of CMB radiation. The electrons boost the energies of the CMB light into the X-ray band, allowing the jets to be detected by Chandra, even at this great distance.
Inset at our upper righthand corner is an X-ray image depicting this interaction. Here, a bright white circle is ringed with a band of glowing purple energy. The jet is the faint purple line shooting off that ring, aimed toward our upper right, with a blob of purple energy at its tip.
News Media ContactMegan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Lane Figueroa
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
lane.e.figueroa@nasa.gov
Starlink satellites are leaking radio signals that may ruin astronomy
Thu 12 Jun 10:00: Harnessing the power of multi-tracer intensity mapping to study early galaxy formation
Intensity mapping is a powerful technique for mapping the Universe using a variety of tracers, including both spectral lines and continuum emission. It serves as a highly complementary approach to traditional galaxy surveys, especially at high redshift where detecting individual galaxies becomes increasingly expensive and challenging. In this talk, I will provide a brief overview of my past and ongoing efforts to explore how multi-tracer intensity mapping can be leveraged to reveal the physics of early galaxy formation and its large-scale impact.
- Speaker: Guochao Sun, Northwestern University (Remote)
- Thursday 12 June 2025, 10:00-11:00
- Venue: Martin Ryle Meeting Room, KICC + Online.
- Series: 21cm Discussion Group; organiser: Harry Bevins.
Thu 12 Jun 14:00: The enigmatic long-period radio transients
The long-period radio transients are a newly-discovered class of Galactic radio sources that produce pulsed emission lasting tens of seconds to several minutes, repeating on timescales of tens of minutes to hours. Such cadence is unprecedented, and there is currently no clear emission mechanism or progenitor that can explain the observations, which include complex polarisation behaviour, pulse microstructure, and activity windows that range from hours to decades.
Could they be ultra-long period magnetars, and connected to the phenomenon of Fast Radio Bursts? Could they be white dwarf pulsars, defying the expectations of the magnetic field evolution of these stellar remnants? In this talk I will describe the ten discoveries made so far, informative simulations of their evolution, the potential physical explanations, and the prospects for detecting more of these sources in ongoing and upcoming radio surveys, that will help uncover their true nature.
- Speaker: Prof. Natasha Hurley-Walker (Curtin University)
- Thursday 12 June 2025, 14:00-15:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.