Sinyal tersebut terdeteksi dari Beta Pictoris b, sebuah planet raksasa gas dengan massa sekitar 12 kali Jupiter. Planet ini mengorbit bintang muda Beta Pictoris yang memiliki massa sekitar 1,75 kali Matahari. Penemuan itu dilakukan tim peneliti menggunakan MeerKAT, jaringan 64 antena teleskop radio di Afrika Selatan. Para astronom menemukan semburan radio yang berulang dan berhasil melokalisasi sumbernya pada Beta Pictoris b, bukan pada bintang induknya. Profesor astronomi Harvard, Edo Berger, mengatakan emisi tersebut berkaitan dengan medan magnet planet. Prosesnya diduga mirip dengan pembentukan aurora di Bumi. "Untuk mendeteksi gelombang radio pada frekuensi yang kami amati, diperlukan medan magnet yang sangat kuat," ujar Berger, dikutip dari CNN , Sabtu (3/10/2026). Medan magnet Beta Pictoris b diperkirakan setidaknya 200 kali lebih kuat dibandingkan medan magnet Jupiter. Ketika partikel bermuatan bergerak secara spiral di dalam medan magnet yang kuat, proses tersebut dapat menghasilkan aurora sekaligus memancarkan gelombang radio. Fenomena ini dikenal sebagai emisi radio aurora. Sebelumnya, fenomena serupa telah diamati pada Jupiter, Saturnus, Matahari, sejumlah bintang, dan katai cokelat. Deteksi tersebut dinilai penting karena salah satu tantangan utama dalam pencarian emisi radio dari eksoplanet adalah memastikan sumber sinyal. Sebelumnya, indikasi emisi radio dari planet di luar tata surya pernah ditemukan, tetapi para astronom belum dapat sepenuhnya menyingkirkan kemungkinan bahwa sinyal berasal dari bintang induknya. Joseph Callingham dari Anton Pannekoek Institute for Astronomy, Universitas Amsterdam, yang tidak terlibat dalam penelitian, menilai aspek tersebut menjadi salah satu keunikan studi terbaru. Menurut Callingham, tim penelitian berhasil melokalisasi emisi pada planet itu sendiri dan memisahkannya dari bintang induknya. Jika dikonfirmasi, temuan ini dapat membuka cara baru untuk mempelajari eksoplanet. Emisi radio aurora memungkinkan astronom mempelajari medan magnet serta interaksi planet dengan lingkungan antariksa di sekitarnya yakni karakteristik yang sulit diketahui hanya melalui metode pengamatan lain. Meski hasilnya menarik, penelitian tersebut belum menjadi kesimpulan final. Makalah yang memuat temuan ini diunggah pada 15 September melalui platform pracetak arXiv dan masih menjalani proses peer review . Para ilmuwan di luar tim penelitian pun meminta agar hasil tersebut ditafsirkan secara hati-hati hingga proses penelaahan selesai. Beta Pictoris b berada dalam sistem keplanetan yang diperkirakan baru berusia sekitar 23 juta tahun, jauh lebih muda dibandingkan tata surya yang berusia sekitar 4,5 miliar tahun. Sistem ini juga memiliki planet lain, komet, serta piringan besar yang terdiri atas debu dan puing sisa pembentukan planet. Jika deteksi tersebut nantinya terkonfirmasi, keberadaan medan magnet yang sangat kuat pada Beta Pictoris b dapat memberikan petunjuk baru mengenai struktur dan atmosfer planet-planet di luar tata surya. Tim peneliti kini telah mengajukan waktu pengamatan teleskop tambahan untuk mempelajari Beta Pictoris b lebih jauh, termasuk mencari tahu mengapa planet raksasa muda tersebut memiliki medan magnet yang begitu kuat. arXiv melaporkan hal serupa. Planetary magnetic fields shape atmospheric escape, mediate interactions with stellar winds, and encode information about planetary interiors 1 , yet they have not been directly measured for planets beyond the Solar System. A direct observable signature is auroral radio emission produced by the electron cyclotron maser instability, whose highest emitted frequency is set by the magnetic field strength at its source 2 . Although auroral radio bursts are observed in Solar System planets and in some ultracool dwarfs 3 , 4 , 5 , no radio detection has previously been unambiguously localized to an extrasolar planet rather than its host star 6 , 7 . We detect rapid, recurring, and highly circularly polarized bursts, as well as persistent emission, at frequencies of 0.85 to 3.5 GHz. CNN melaporkan hal serupa. An artist’s interpretation depicts Beta Pictoris b (right) as it orbits its host star. “I know radio signals are associated with searches for extraterrestrial intelligence,” said Edo Berger, a professor of astronomy at Harvard University. The discovery, described in a new paper awaiting publication in a peer-reviewed journal, traces repeating radio bursts that appear to come from the exoplanet Beta Pictoris b, located 63 light-years from Earth — a short distance, astronomically speaking. The gas giant, about 12 times the mass of Jupiter, is one of three planets orbiting a young star that is 1.75 times as massive as the sun. arXiv melaporkan hal serupa. Focus to learn more arXiv-issued DOI via DataCite Submission history From: Kevin Ortiz Ceballos [ view email ] [v1] Tue, 15 Sep 2026 06:44:39 UTC (972 KB) Full-text links: Access Paper: View a PDF of the paper titled Discovery of radio emission from the exoplanet $\beta$ Pictoris b, by Kevin N. Ortiz Ceballos and 2 other authors View PDF HTML (experimental) TeX Source view license Current browse context: astro-ph.EP prev | next new | recent | 2026-09 Change to browse by: astro-ph References Citations NASA ADS Google Scholar Semantic Scholar export BibTeX citation Loading... Sci.News melaporkan hal serupa. First discovered in 2008 by astronomers using ESO’s Very Large Telescope, Beta Pictoris b is a gas giant 9 to 13 times the mass of Jupiter. The planet orbits its host star, Beta Pictoris , at a distance of 8 times the Earth-Sun distance. The system is located around 63 light-years away in the constellation of Pictor, and is estimated to be only 23 million years old. “The most massive planet in the system, Beta Pictoris b, reaches an angular separation of up to 0.55’’ across its 24-year orbit, and the host star is magnetically quiet, making the system an ideal target for radio observations,” said Kevin Ortiz Ceballos from the Harvard Smithsonian’s Center for Astrophysics and his colleagues. arXiv melaporkan hal serupa. We identify the emission as electron cyclotron maser radiation, which implies a magnetic field of ≳ 1.25 \gtrsim 1.25 kG at the planet — the first such direct field strength measurement for an exoplanet. Auroral radio emission is a direct, model-independent probe of a planet’s magnetic field; it consists of coherent emission from electrons accelerated along magnetic field lines, and it bears signatures of planetary rotation, magnetic obliquity and magnetospheric plasma content 8 , 9 . In the Solar System, Earth and the four giant planets all emit such radiation, at kilometric (Earth, Saturn, Uranus, Neptune) and decametric (Jupiter) wavelengths 10 . Similarly, gigahertz-frequency, strongly-polarized bursts have been detected 4 , 11 , 12 in ultracool dwarfs (UCDs) down to the planetary mass regime 5 , which are phenomenologically similar to planetary aurorae 13 , 14 . CNN melaporkan hal serupa. Processes associated with the planet’s magnetic field produce the radio emission, according to Berger, a researcher at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts. “In order to see radio waves that extend all the way to the frequencies that we observed, you need an incredibly strong magnetic field,” added Berger, a coauthor of the paper posted September 15 to the preprint platform ArXiv. art002e009287 (April 6, 2026) – Earth sets at 6:41 p.m. EDT, April 6, 2026, over the Moon’s curved limb in this photo captured by the Artemis II crew during their journey around the far side of the Moon. Sci.News melaporkan hal serupa. Because the highest frequency of this type of emission depends directly on the strength of the magnetic field at its source, the detection allowed the scientists to calculate a minimum magnetic field strength for beta Pictoris b of about 1.25 kilogauss several thousand times stronger than Earth’s own magnetic field. “This constitutes the first direct measurement of magnetic field strength for an exoplanet, and is consistent with dynamo-scaling predictions for a young, massive giant planet,” they said. arXiv melaporkan hal serupa. We observed the β \beta Pic system with the MeerKAT array on four occasions in 2025 and 2026, in the L band (0.8–1.7 GHz) and S band (1.7–3.5 GHz); see Extended Data Table 1; Methods. We tie the radio image to the Gaia celestial reference frame using compact radio counterparts of 9 Gaia -identified quasars detected across the field, supplemented by one VLBI calibrator, and solve for an affine frame-tie correction 34 , 35 (translation plus rotation, scale and shear; Methods, Extended Data Table 2). After applying the correction (which shifts the position by less than its 1 σ 1\sigma uncertainty) and propagating all uncertainties by Monte Carlo sampling, the radio source coincides with the known position of β \beta Pic b (Fig. The incorporated systematics are based on two empirical tests (Methods): a frequency-differential test of ionospheric refraction, which finds a median per-sightline chromatic residual of only 32 mas (Extended Data Fig. CNN melaporkan hal serupa. “The magnetic field on this planet is at least 200 times stronger than the magnetic field of Jupiter,” Berger said, referring to Beta Pictoris b. Jupiter’s magnetic field, according to NASA , is powerful enough to generate a magnetosphere — the region of space influenced by the magnetic field — that ranks as the largest structure in our solar system, stretching up to 2 million miles (3 million kilometers) toward the sun. “As these very high-energy particles are spiraling inside the magnetic field, along with the aurora they also produce radio waves,” Berger said. NASA/JPL-Caltech/SwRI Mystery of Jupiter’s northern lights solved after 40 years, scientists say arXiv melaporkan hal serupa. 2), and a point source injection recovery test, which shows the fitted position uncertainty to be accurate to ≈ 1.1 \approx 1.1 of the fitting covariance (Extended Data Fig. The emission from β \beta Pic b is composed of recurring, rapidly-variable bursts with large circular polarization of ≈ 40 − 70 % \approx 40-70\% , as well as fainter inter-burst persistent emission (Fig. The strong circular polarization and rapid variability point to electron cyclotron maser instability (ECMI) emission 2 , 36 for the bursts; we disfavor plasma emission because it would require implausibly high plasma densities (Methods). The circular polarization handedness is not fixed, with left-handed bursts in the 2025 May 31 L-band epoch and a right-handed burst in the 2026 May 2 S-band epoch (Fig. CNN melaporkan hal serupa. Magnetic fields have implications for the structure of exoplanets and their atmospheres, according to Berger. “Radio observations can give us a completely new view on planets beyond our system,” he said. There had been hints of radio emissions from exoplanets before, but none had been confirmed, largely because it couldn’t be ruled out that the source was actually the host star, said Joseph Callingham, an associate professor at the Anton Pannekoek Institute for Astronomy of the University of Amsterdam in the Netherlands. The Beta Pictoris system is astronomically very young at about 23 million years old compared with our own solar system’s age of 4.5 billion years. arXiv melaporkan hal serupa. 3 ), consistent with auroral ECMI in which the handedness is set by magnetic field orientation and rotation 11 , 14 . For ECMI, the emission frequency is the electron cyclotron frequency, ν c = e B / 2 π m e c ≈ 2.8 ( B / 1 kG ) GHz \nu_{\rm c}={eB}/{2\pi m_{e}c}\approx 2.8\left({B}/{1~{\rm kG}}\right)~{\rm GHz} 36 . The burst detected in the S-band is also the most circularly polarized ( ≈ 70 % \approx 70\% ) and is detected up to 3.5 GHz, the top of the observing band, therefore requiring a magnetic field of B ≳ 1.25 B\gtrsim 1.25 kG at the emission site. This constitutes the first direct measurement of magnetic field strength for an exoplanet, and is consistent with dynamo-scaling predictions for a young, massive giant planet 37 ; see Fig. CNN melaporkan hal serupa. Beta Pictoris b — the planet from which the radio signal potentially originates — was discovered in 2008 . Two additional planets, Beta Pictoris c and Beta Pictoris d, were discovered in 2019 and 2026 , respectively. arXiv melaporkan hal serupa. The inferred field strength further rules out stellar emission since the upper limit 31 for the host star’s dipole field strength is ≲ 0.3 \lesssim 0.3 kG (Methods). The resulting shear drives field-aligned currents that precipitate electrons and drive auroral ECMI, with the radiated power set by the rotation rate, field strength, plasma mass-loading rate and ionospheric conductance 41 , 42 , 43 . Rotational modulation is expected from a magnetosphere-ionosphere coupling scenario 43 ; the ≈ 8 \approx 8 hr separation between the first and third bursts in L-band (Fig. 3 ) is comparable to the planetary rotation period, and may be a signature of such modulation. arXiv melaporkan hal serupa. First, stellar wind impinging on the planetary magnetosphere, analogous to how Jupiter’s hectometric emission is produced 48 , has been predicted to produce radio emission from the β \beta Pic planets 49 , 50 . The second driver, planet–moon (Io–Jupiter-type) Alfvénic interaction 53 , 54 is energetically insufficient. Rotationally-driven coupling accounts for the power and modulation observed in the auroral emission of UCDs 43 that β \beta Pic b’s bursts closely resemble 5 , and many of these UCDs are isolated objects with no companion that can supply an external wind. Because the emission should be modulated by rotation, continued radio monitoring can reveal the planet’s magnetic obliquity and geometry 58 . arXiv melaporkan hal serupa. More broadly, seven more directly-imaged giant exoplanets in five other systems within 45 pc lie at separations where the astrometric localization technique used here applies, and a ∼ 5 × \sim 5\times to 7 × 7\times improvement in instrument sensitivity, expected from next-generation radio observatories, will bring them within reach of detection. We observed the β \beta Pic system with MeerKAT on four epochs between 2025-02 and 2026-05 (Extended Data Table 1), in the L band (0.856–1.712 GHz) and S band (1.75–3.5 GHz), using the standard 4096-channel mode with 8-s integrations. Ortiz Ceballos et al., in prep.); following the initial detection we obtained a 9.3-hr L-band follow-up through Director’s Discretionary Time, and subsequently S-band Open Time. For the S-band campaign we first split the array into two subarrays covering 1.7–2.6 and 2.6–3.5 GHz simultaneously, confirmed emission from the source across the full band, then dedicated an observing block to the 2.6–3.5 GHz sub-band for maximum angular resolution and sensitivity. arXiv melaporkan hal serupa. The bandpass and gain calibrators were J0408 − - 6545 and J0538 − - 4405 respectively; J0521+1638 (3C138) was added as a polarization calibrator for all but the discovery epoch. The calibrated measurement sets were provided from the SARAO Science Data Processor (SDP) pipeline katsdpcal ’s standard mode, and we used WSCLEAN 59 , 60 for imaging in Stokes I and V. For astrometry, we imaged with Briggs robustness 0.0, because the MeerKAT beam becomes non-Gaussian at higher robustness 61 , 62 while lower robustness reduced signal-to-noise and astrometric precision in our tests. A large-field continuum image of the 2026-05-02 S-band observation, produced from this SDP-calibrated measurement set, was the image used for the astrometric registration of the radio source to β \beta Pic b. arXiv melaporkan hal serupa. Separately, we also calibrated and imaged the uncalibrated measurement sets with the POLKAT pipeline 63 , a version of OXKAT 64 modified to implement polarization calibration. POLKAT uses CASA 65 for reference calibration, Tricolour 66 for flagging, QuartiCal 67 for self-calibration, and WSCLEAN 59 , 60 for imaging. Because MeerKAT has orthogonal linear feeds, Stokes V V occupies the imaginary crosshand correlations 68 and can be recovered for a strongly circularly-polarized source even without polarization calibration. Here, we used Briggs robustness +0.25 to improve signal-to-noise ratio (at a mild cost of angular resolution) since we do not use these images for astrometry.
Fakta Kunci
- 1Sinyal tersebut terdeteksi dari Beta Pictoris b, sebuah planet raksasa gas dengan massa sekitar 12 kali Jupiter.
- 2Planet ini mengorbit bintang muda Beta Pictoris yang memiliki massa sekitar 1,75 kali Matahari.
- 3Penemuan itu dilakukan tim peneliti menggunakan MeerKAT, jaringan 64 antena teleskop radio di Afrika Selatan.
- 4"Untuk mendeteksi gelombang radio pada frekuensi yang kami amati, diperlukan medan magnet yang sangat kuat," ujar Berger, dikutip dari CNN , Sabtu (3/10/2026).
- 5Medan magnet Beta Pictoris b diperkirakan setidaknya 200 kali lebih kuat dibandingkan medan magnet Jupiter.
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