Showing posts with label TWA 7. Show all posts
Showing posts with label TWA 7. Show all posts

Friday, August 29, 2025

A Dusty Disk Points to a Potential Planet

Hubble Space Telescope observations of the Beta Pictoris debris disk, which led to a planet discovery.
Credit:
NASA, ESA, and D. Apai and G. Schneider (University of Arizona)

JWST observations of a nearby star’s debris disk recently revealed what may be one of the lowest-mass planets ever imaged.

How to Find a Small Planet

Though it remains a formidable technical challenge, astronomers have gotten fairly good at taking images of planets around other stars by carefully blocking the light of the host and searching for the small points of light that remain. However, though this technique is well-suited for discovering large, bright, high-mass planets, their lower-mass cousins below the size of Jupiter remain challenging to detect. To get pictures of these smaller worlds, astronomers must resort to detective work and search for signs of their presence through indirect means.

One promising approach is to look not for the planet itself, but rather its effect on the dusty disk of material around the star. These structures, called debris disks, are constantly replenished by planetesimals colliding and grinding one another to dust. If a planet happens to orbit within this disk, it will “stir” the dust into distinctive patterns including rings and spiral arms. If astronomers observe that a star has a debris disk with gaps or spirals, they can analyze those substructures and deduce where a planet might be hiding.

A mid-infrared image of TWA 7’s debris disk and candidate planet.
Credit:
ESA/Webb, NASA, CSA, A.M. Lagrange, M. Zamani (ESA/Webb); CC BY 4.0

The Star of this Show: TWA 7

TWA 7 is a tiny M-dwarf star just over 100 light-years from Earth. Data from the Spitzer Space Telescope revealed that TWA 7 was unusually bright when observed at infrared wavelengths, which hinted that there might be a warm, dusty disk surrounding the star. Follow-up observations with the Hubble Space Telescope and several major ground-based facilities confirmed that this star successfully met all the conditions listed above: TWA 7 is surrounded by a face-on debris disk with rings and a faint spiral arm. Using all of this information, astronomers predicted that a Saturn-mass planet might lie in a low-density pocket of the disk just beside the star.

This prediction led to a search with JWST last summer. Initial observations taken at mid-infrared wavelengths revealed a bright dot sitting near the predicted location of the planet. However, with just these observations, it was hard to confidently say that this source wasn’t just a distant background galaxy that happened to appear there by chance. To help settle the matter, JWST took another look in two different near-infrared wavelength bands a few weeks later.

New JWST observations of TWA 7. The sources labeled C5 and C6 are planet candidates. C6 is located at the same place as the planet candidate identified in mid-infrared observations, making it a strong candidate. C5 requires further observations to understand if it is real or an artifact. Credit: Crotts et al. 2025

Revisiting TWA 7

A team led by Katie Crotts (Space Telescope Science Institute) recently published these later observations. These new data show a dot in the exact same place as before, and with a color that’s much more planet-like than galaxy-like.

While this adds plenty of evidence to the planetary interpretation, the team cautions that one more set of follow-up observations is needed to be confident that this is, in fact, a planet. Assuming future observations back up these first hints, however, this would be the lowest-mass planet ever imaged, and a happy conclusion to a detective story that started with dust.

By Ben Cassese

Citation

“Follow-Up Exploration of the TWA 7 Planet–Disk System with JWST NIRCam,” Katie Crotts et al 2025 ApJL 987 L41.

doi:10.3847/2041-8213/ade798



Friday, June 27, 2025

Likely Saturn-Mass Planet Imaged by NASA Webb Is Lightest Ever Seen

Astronomers using NASA’s James Webb Space Telescope have captured compelling evidence of a planet with a mass similar to Saturn orbiting the young nearby star TWA 7. In this image combining ground-based data from ESO’s Very Large Telescope (VLT) and data from Webb’s MIRI (Mid-Infrared Instrument), light from the star TWA 7 has been subtracted. The location of the star is marked with a circle and a star symbol at the center of the image. The blue color represents data from the VLT’s SPHERE instrument, which showcases the location of the disk surrounding the host star. MIRI data is shown in orange. The bright orange spot to the upper right of the star is the source identified as TWA 7 b, within the debris disk. The more distant orange spot visible in the left of the image is an unrelated background star. Credits/Image: NASA, ESA, CSA, Anne-Marie Lagrange (CNRS, UGA), Mahdi Zamani (ESA/Webb)



Astronomers using NASA’s James Webb Space Telescope have captured compelling evidence of a planet with a mass similar to Saturn orbiting the young nearby star TWA 7. If confirmed, this would represent Webb’s first direct image discovery of a planet, and the lightest planet ever seen with this technique outside the solar system.

The international team detected a faint infrared source in the disk of debris surrounding TWA 7 using Webb’s MIRI (Mid-Infrared Instrument). The distance between the source and TWA 7 is estimated to be about 50 times the distance of the Earth from the Sun. This matches the expected position of a planet that would explain key features seen in the debris disk. The results published Wednesday, June 25 in the journal Nature.

Using MIRI’s coronagraph, the researchers carefully suppressed the bright glare of the host star to reveal faint nearby objects. This technique, called high-contrast imaging, enables astronomers to directly detect planets that would otherwise be lost in the overwhelming light from their host star. After subtracting residual starlight using advanced image processing, a faint infrared source was revealed near TWA 7. The team ruled out an object in our solar system that happened to be in the same part of the sky as the source. While there is a very small chance that it is a background galaxy, the evidence strongly points to the source being a previously undiscovered planet.

The source is located in a gap in one of three dust rings that were discovered around TWA 7 by previous ground-based observations. The object’s brightness, color, distance from the star, and position within the ring are consistent with theoretical predictions for a young, cold, Saturn-mass planet that is expected to be sculpting the surrounding debris disk.

“Our observations reveal a strong candidate for a planet shaping the structure of the TWA 7 debris disk, and its position is exactly where we expected to find a planet of this mass,” said Anne-Marie Lagrange, CNRS researcher at the Observatoire de Paris-PSL and Université Grenoble Alpes in France, lead author of the paper.

“This observatory enables us to capture images of planets with masses similar to those in the solar system, which represents an exciting step forward in our understanding of planetary systems, including our own,” added co-author Mathilde Malin of Johns Hopkins University and the Space Telescope Science Institute in Baltimore.

Initial analysis suggests that the object — referred to as TWA 7 b — could be a young, cold planet with a mass around 0.3 times that of Jupiter (about 100 Earth masses, or one Saturn mass) and a temperature near 120 degrees Fahrenheit (47 degrees Celsius). Its location aligns with a gap in the disk, hinting at a dynamic interaction between the planet and its surroundings.

Debris disks filled with dust and rocky material are found around both young and older stars, although they are more easily detected around younger stars as they are brighter. They often feature visible rings or gaps, thought to be created by planets that have formed around the star, but such a planet has yet to be directly detected within a debris disk. If verified, this discovery would mark the first time a planet has been directly associated with sculpting a debris disk, and could offer the first observational hint of a “trojan disk” — a collection of dust trapped in the planet’s orbit.

TWA 7, also known as CE Antilae, is a young (about 6.4 million years old) red dwarf star located about 34 light-years away in the TW Hydrae association. Its nearly face-on disk made it an ideal target for Webb’s high-sensitivity mid-infrared observations.

The findings highlight Webb’s ability to explore previously unseen, low-mass planets around nearby stars. Ongoing and future observations will aim to better constrain the properties of the candidate, verify its planetary status, and deepen our understanding of planet formation and disk evolution in young systems.

These observations were taken as part of the Webb observing program 3662.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).




About This Release

Credits:

Media Contact:

Bethany Downer
ESA/Webb, Baltimore

Christine Pulliam
Space Telescope Science Institute, Baltimore

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

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Wednesday, June 24, 2020

Young Planets Bite the Dust

noirlab2014a/
noirlab2014b (Labeled) – GPI Circumstellar Disks
Six circumstellar disks selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). These images highlight the diversity of shapes and sizes that these disks can take and show the outer reaches of star systems in their formative years. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley). Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin. 3906 × 2642 jpg  -  3906 × 2642 jpg  (Labeled)

noirlab2014c – HD 129590
A circumstellar disk around star HD 129590 selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI).  Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley).  Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin. 1200 × 1200 jpg

noirlab2014d – HD 117214
A circumstellar disk around star HD 117214 selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin. noirlab2014e – HD 111520 A circumstellar disk around star HD 111520 selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin. 1200 × 1200 jpg

noirlab2014e – HD 111520
A circumstellar disk around star HD 111520 selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.  1200 × 1200 jpg

noirlab2014f – HR 4796 A
A circumstellar disk around star HR 4796 A selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.  1200 × 1200 jpg

noirlab2014g – TWA 7
A circumstellar disk around star TWA 7 selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin1200 × 1200 jpg

noirlab2014h – HD 32297
A circumstellar disk around star HD 32297 selected from the larger sample of 26 disks obtained with the Gemini South telescope in Chile using the Gemini Planet Imager (GPI). Credit: International Gemini Observatory/NOIRLab/NSF/AURA/T. Esposito (UC Berkeley) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.  1200 × 1200 jpg

noirlab2014a – Images of Dusty Star Systems Revealed by the Gemini Planet Imager Animation of the Solar System and moving outward to indicate stars observed with the Gemini Planet Imager (GPI) mounted on the Gemini South telescope in Chile. Highlighted are the images of the dusty rings encircling some of these young stars. More than 100 researchers have contributed to GPI and the GPI Exoplanet Survey, whose work is highlighted in this video. The work was supported by the National Science Foundation (NSF) and NASA. Created by Jenny Patience and Ric Alling, Arizona State University, with scientific input from Justin Hom (ASU), Paul Kalas (UC Berkeley), Tom Esposito (UC Berkeley) and Franck Marchis (SETI Institute). Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. Patience & R. Alling (Arizona State University)/T. Esposito (UC Berkeley)
noirlab2014a mp4



Astronomers unveil new collection of planet-forming dusty star systems


These orange swirls of dust are snapshots from the largest collection of sharp, detailed images of dusty debris disks around young stars — published this week by an international group of astronomers. The images — captured by the 8-meter Gemini South telescope using the Gemini Planet Imager — illustrate the variety of shapes and sizes that stellar systems can take during their infancy. Unexpectedly, the majority of these systems display evidence of planet formation.

These remarkable portraits of dusty disks are a selection from 26 new images of debris disks obtained by the Gemini Planet Imager (GPI) at the international Gemini Observatory, a Program of NSF’s NOIRLab. These images highlight the diversity of shapes and sizes that these disks can take and show the outer reaches of exoplanetary systems in their formative years. The young stars imaged, which range from tens of millions to a few hundred million years old, are at the ideal age to settle down and raise planets. The forming planets sculpt the dust disk and leave behind gaps and warps that are indirect clues to their existence and motion.

While debris disks have been imaged before, this new cohort of 26 disks represents one of the largest samples to be imaged with highly uniform data quality. This enables detailed comparison of the observations, a unique breakthrough in debris disk surveys. Thirteen of the disks form a perfect natural laboratory, all belonging to the Scorpius–Centaurus stellar association, roughly 400 light-years from Earth. The group of stars, which were born in the same region at roughly the same time, enables astronomers to compare the architectures of a variety of young planetary systems developing under different conditions.

GPI was able to capture these dusty disks with the help of some ingenious astronomical engineering.

GPI is sensitive to the polarization of light, allowing it to distinguish dust-scattered light, which is polarized, from the unpolarized light emanating from the stars. This gives GPI the impressive ability to improve the contrast of images and capture disks that are 10 million times fainter than their parent stars.

Measuring polarization is only one of GPI’s tricks, however — the instrument also exploits a coronagraph and adaptive optics to get the most from its observations [1][2].

GPI’s precision is in large part due to its perch on the 8-meter Gemini South telescope on Cerro Pachón in Chile. The dry conditions, high altitude, and dark skies are perfect for cutting-edge astronomical research. By combining this exquisite location with some engineering ingenuity, GPI is able to capture images as sharp as those from the Hubble Space Telescope — and detect objects up to three times closer to the host stars [3].

GPI’s first-rate observing abilities enabled this work, part of the Gemini Planet Imager Exoplanet Survey (GPIES), a 4-year search for light emitted by giant gas planets orbiting more than 500 of the youngest stars near the Sun. As well as doubling the number of debris disks imaged at this high resolution, the survey uncovered six giant exoplanets and four brown dwarfs. Surveys such as GPIES are a perfect way to screen targets for the next generation of space- and ground-based telescopes.

“The Gemini instrument program continues to provide unique science opportunities. This combination of GPI mounted upon a large ground-based telescope is delivering exciting new details about the process of how planets form,” said Martin Still, NSF Program Manager for the Gemini Observatory partnership.

The GPIES survey concluded in 2019, but the investment and technical capability of the Gemini Planet Imager will continue with an upgrade to GPI’s hardware to improve its resolution and sensitivity [4].

The new “GPI 2.0,” is slated for a future installation at Gemini North atop Maunakea in Hawai‘i, where it will search the less-observed northern hemisphere skies for more exoplanets and debris disks. GPI 2.0 will also continue the work of scouting out targets for the next generation of exoplanet missions, setting the scene for new insights into the mystery of planet formation.




Notes

[1] Coronagraphs are devices which block light coming directly from a central star, allowing the faint disk to be seen. The presence of GPI’s coronagraph can be inferred from the conspicuous black circle at the center of these images.

[2] Adaptive Optics is a cutting-edge astronomical technique that uses deformable mirrors to correct blurring and distortions caused by turbulence in Earth’s atmosphere.

[3] GPI’s coronagraph blocks a smaller region around the star and better suppresses noise at small angular separations from the star, compared to HST’s coronagraph.

[4] The upgrade to GPI is funded by the NSF and by the Heising-Simons Foundation.




More information


This research was presented in the paper Debris Disk Results from the Gemini Planet Imager Exoplanet Survey’s Polarimetric Imaging Campaign in The Astronomical Journal.

The team is composed of Thomas M. Esposito (University of California, Berkeley), Paul Kalas, (University of California, Berkeley, SETI Institute, and Foundation for Research and Technology – Hellas), Michael P. Fitzgerald (University of California, Los Angeles), Maxwell A. Millar-Blanchaer (NASA Hubble Fellow at NASA Jet Propulsion Laboratory), Gaspard Duchêne (University of California,Berkeley and Université Grenoble Alpes), Jennifer Patience (Arizona State University), Justin Hom (Arizona State University), Marshall D. Perrin (Space Telescope Science Institute), Robert J. De Rosa (Kavli Institute for Particle Astrophysics and Cosmology), Eugene Chiang (University of California, Berkeley), Ian Czekala (NASA Hubble Fellowship Program Sagan Fellow at the University of California, Berkeley), Bruce Macintosh (Kavli Institute for Particle Astrophysics and Cosmology), James R. Graham (University of California, Berkeley), Megan Ansdell (University of California, Berkeley), Pauline Arriaga (University of California, Los Angeles), Sebastian Bruzzone (The University of Western Ontario), Joanna Bulger (Pan-STARRS Observatory), Christine H. Chen (Space Telescope Science Institute), Tara Cotton (University of Georgia), Ruobing Dong (University of Victoria), Zachary H. Draper (University of Victoria and National Research Council of Canada), Katherine B. Follette (Amherst College), Li-Wei Hung (University of California, Los Angeles), Ronald Lopez (University of California, Los Angeles), Brenda C. Matthews (National Research Council of Canada and University of Victoria), Johan Mazoyer (NASA Hubble Fellow at NASA Jet Propulsion Laboratory), Stan Metchev (The University of Western Ontario and Stony Brook University), Julien Rameau (Université de Montréal), Bin Ren (Johns Hopkins University and Space Telescope Science Institute), Malena Rice (Yale University), Inseok Song (University of Georgia), Kevin Stahl (University of California, Los Angeles), Jason Wang (California Institute of Technology and University of California, Berkeley), Schuyler Wolff (Leiden University), Ben Zuckerman (University of California, Los Angeles), S. Mark Ammons (Lawrence Livermore National Laboratory), Vanessa P. Bailey (NASA Jet Propulsion Laboratory), Travis Barman (University of Arizona), Jeffrey Chilcote (Kavli Institute for Particle Astrophysics and Cosmology and University of Notre Dame), Rene Doyon (Université de Montréal), Benjamin L. Gerard (University of Victoria and National Research Council of Canada), Stephen J. Goodsell (Gemini Observatory), Alexandra Z. Greenbaum (University of Michigan), Pascale Hibon (Gemini Observatory), Sasha Hinkley (University of Exeter), Patrick Ingraham (Vera C. Rubin Observatory), Quinn Konopacky (University of California San Diego), Jérôme Maire (University of California San Diego), Franck Marchis (SETI Institute), Mark S. Marley (NASA Ames Research Center), Christian Marois (University of Victoria and National Research Council of Canada), Eric L. Nielsen (SETI Institute and Kavli Institute for Particle Astrophysics and Cosmology), Rebecca Oppenheimer (American Museum of Natural History), David Palmer (Lawrence Livermore National Laboratory), Lisa Poyneer (Lawrence Livermore National Laboratory), Laurent Pueyo (Space Telescope Science Institute), Abhijith Rajan (Space Telescope Science Institute), Fredrik T. Rantakyrö (Gemini Observatory), Jean-Baptiste Ruffio (Kavli Institute for Particle Astrophysics and Cosmology), Dmitry Savransky (Cornell University), Adam C. Schneider (Arizona State University), Anand Sivaramakrishnan (Space Telescope Science Institute), Rémi Soummer (Space Telescope Science Institute), Sandrine Thomas (Vera C. Rubin Observatory), and Kimberly Ward-Duong (Amherst College).

NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.



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