Letters

  • Letter |

    The MASCOT lander observed a boulder on the surface of asteroid Ryugu up close. The boulder’s low thermal inertia is closer to fine regolith or comets rather than stony boulders, indicating high porosity and low tensile strength. Orbit measurements confirm that Ryugu’s surface is covered with similar boulders.

    • M. Grott
    • , J. Knollenberg
    • , M. Hamm
    • , K. Ogawa
    • , R. Jaumann
    • , K. A. Otto
    • , M. Delbo
    • , P. Michel
    • , J. Biele
    • , W. Neumann
    • , M. Knapmeyer
    • , E. Kührt
    • , H. Senshu
    • , T. Okada
    • , J. Helbert
    • , A. Maturilli
    • , N. Müller
    • , A. Hagermann
    • , N. Sakatani
    • , S. Tanaka
    • , T. Arai
    • , S. Mottola
    • , S. Tachibana
    • , I. Pelivan
    • , L. Drube
    • , J.-B. Vincent
    • , H. Yano
    • , C. Pilorget
    • , K. D. Matz
    • , N. Schmitz
    • , A. Koncz
    • , S. E. Schröder
    • , F. Trauthan
    • , M. Schlotterer
    • , C. Krause
    • , T.-M. Ho
    •  & A. Moussi-Soffys
  • Letter |

    Of the 72 known fast radio burst (FRB) sources only two have been observed to emit repeat bursts. By calculating the volumetric occurrence rate of non-repeating FRBs, Vikram Ravi shows that there are not enough candidate cataclysmic progenitor events for most FRBs to be one-off phenomena, and therefore most FRBs must repeat.

    • Vikram Ravi
  • Letter |

    A combination of laboratory experiments and numerical modelling shows that a 2–3 cm-thick layer of silica aerogel deployed over the temperate regions of Mars could maintain a surface environment conducive to liquid water all year round. Such an approach would create a habitable setting for photosynthetic life.

    • R. Wordsworth
    • , L. Kerber
    •  & C. Cockell
  • Letter |

    Combining gravitational-wave and electromagnetic data with new radio observations of GW170817, an improved measurement of $$H_0 = 70.3_{-5.0}^{+5.3}\, {\mathrm{km}}\, {\mathrm{s}}^{-1}\,{\mathrm{Mpc}}^{-1}$$ H 0 = 70 . 3 - 5.0 + 5.3 km s - 1 Mpc - 1 is derived. Fifteen more GW170817-like events with radio data could resolve the Hubble constant tension.

    • K. Hotokezaka
    • , E. Nakar
    • , O. Gottlieb
    • , S. Nissanke
    • , K. Masuda
    • , G. Hallinan
    • , K. P. Mooley
    •  & A. T. Deller
  • Letter |

    The superbubble containing the Sun is filled with sparse, very hot matter. Creating a three-dimensional map of this Local Bubble using the diffuse interstellar bands (DIBs), Farhang et al. show that, surprisingly, two DIB carriers exist within the bubble itself. The λ5,780 DIB carrier, compared with λ5,797, is the hardier.

    • Amin Farhang
    • , Jacco Th. van Loon
    • , Habib G. Khosroshahi
    • , Atefeh Javadi
    •  & Mandy Bailey
  • Letter |

    The measurement of faint fluxes of photons from across the Universe requires sensitive terahertz detectors, cooled to minimize noise. By using a photomixer with plasmonics-based semiconductors to downconvert the high frequencies, terahertz detection can be accomplished at room temperature.

    • Ning Wang
    • , Semih Cakmakyapan
    • , Yen-Ju Lin
    • , Hamid Javadi
    •  & Mona Jarrahi
  • Letter |

    The Juno spacecraft’s observations of magnetic field perturbations in Jupiter’s polar regions show Birkeland currents associated with aurorae that are weaker than anticipated and filamentary in nature. An asymmetry is observed between the northern and southern auroras.

    • Stavros Kotsiaros
    • , John E. P. Connerney
    • , George Clark
    • , Frederic Allegrini
    • , G. Randall Gladstone
    • , William S. Kurth
    • , Barry H. Mauk
    • , Joachim Saur
    • , Emma J. Bunce
    • , Daniel J. Gershman
    • , Yasmina M. Martos
    • , Thomas K. Greathouse
    • , Scott J. Bolton
    •  & Steven M. Levin
  • Letter |

    Theoretical modelling of velocity maps of high-redshift Lyman α emitters indicates sufficient gas inflow to fuel the central galaxy’s star-formation rate and angular momentum, implying that cold gas accretion is building galaxies at the peak of star formation.

    • D. Christopher Martin
    • , Donal O’Sullivan
    • , Mateusz Matuszewski
    • , Erika Hamden
    • , Avishai Dekel
    • , Sharon Lapiner
    • , Patrick Morrissey
    • , James D. Neill
    • , Sebastiano Cantalupo
    • , Jason Xavier Prochaska
    • , Charles Steidel
    • , Ryan Trainor
    • , Anna Moore
    • , Daniel Ceverino
    • , Joel Primack
    •  & Luca Rizzi
  • Letter |

    A comprehensive set of Hubble and Spitzer observations reveal a hydrogen-rich, low-metallicity atmosphere on the sub-Neptune exoplanet GJ 3470 b. Water vapour is detected, but the planet is surprisingly depleted in methane, possibly because of photochemical or thermal processes. Sub-millimetre-sized Mie-scattering cloud particles partially attenuate the molecular signatures at short wavelength, but are largely transparent beyond 3 µm.

    • Björn Benneke
    • , Heather A. Knutson
    • , Joshua Lothringer
    • , Ian J.M. Crossfield
    • , Julianne I. Moses
    • , Caroline Morley
    • , Laura Kreidberg
    • , Benjamin J. Fulton
    • , Diana Dragomir
    • , Andrew W. Howard
    • , Ian Wong
    • , Jean-Michel Désert
    • , Peter R. McCullough
    • , Eliza M.-R. Kempton
    • , Jonathan Fortney
    • , Ronald Gilliland
    • , Drake Deming
    •  & Joshua Kammer
  • Letter |

    Contractional features such as scarps, ridges and fractures from thrust faults are typical of large silicate bodies such as Mercury and Mars. Evidence for similar features on Ceres suggests the possibility of large-scale contraction on this icy body.

    • Javier Ruiz
    • , Alberto Jiménez-Díaz
    • , Federico Mansilla
    • , Laura M. Parro
    • , Isabel Egea-González
    •  & Michael Küppers
  • Letter |

    The uniformly high 13C/12C ratios of the Tagish Lake meteorite, whose parent body is a D-type asteroid, indicate that at least some D-type asteroids were formed in the cold outer Solar System from a 13C-rich CO2 ice reservoir and subsequently migrated inwards.

    • W. Fujiya
    • , P. Hoppe
    • , T. Ushikubo
    • , K. Fukuda
    • , P. Lindgren
    • , M. R. Lee
    • , M. Koike
    • , K. Shirai
    •  & Y. Sano
  • Letter |

    The predominantly prograde orientation and broad inclination distribution of trans-Neptunian binary objects is reproduced by a three-dimensional hydrodynamical simulation of planetesimal formation driven by the streaming instability, showing evidence of the activation of the streaming instability in the solar protoplanetary disk.

    • David Nesvorný
    • , Rixin Li
    • , Andrew N. Youdin
    • , Jacob B. Simon
    •  & William M. Grundy
  • Letter |

    All trans-Neptunian objects larger than 1,000 km have satellites. A hydrodynamic simulation shows that such satellites were formed by giant impacts that happened before the migration of Neptune and that kept the satellites in a fluid-like state for 104–106 yr.

    • Sota Arakawa
    • , Ryuki Hyodo
    •  & Hidenori Genda
  • Letter |

    A unique merger shock is found in an early phase of two clusters undergoing a major merger, propagating outward along the equatorial plane of the merger. Owing to the rapid approach of the cluster pair, the gas along the merger axis is strongly compressed.

    • Liyi Gu
    • , Hiroki Akamatsu
    • , Timothy W. Shimwell
    • , Huib T. Intema
    • , Reinout J. van Weeren
    • , Francesco de Gasperin
    • , François Mernier
    • , Junjie Mao
    • , Igone Urdampilleta
    • , Jelle de Plaa
    • , Viral Parekh
    • , Huub J. A. Röttgering
    •  & Jelle S. Kaastra
  • Letter |

    X-ray observations of the Coma Cluster show enhanced plasma collision rates due to either particle scattering off microfluctuations caused by plasma instabilities or transport processes that are anisotropic with respect to the local magnetic field.

    • I. Zhuravleva
    • , E. Churazov
    • , A. A. Schekochihin
    • , S. W. Allen
    • , A. Vikhlinin
    •  & N. Werner
  • Letter |

    A minor but important fraction of silicate stardust believed to come from red giant stars is shown to have a supernova origin instead, making the supernova dust fraction among >200-nm-sized presolar silicates significantly higher than previously inferred.

    • Jan Leitner
    •  & Peter Hoppe
  • Letter |

    An exceptionally low delay of 83 minutes between variability in the accretion disk and Hα emission is reported from the nucleus of the dwarf galaxy NGC 4395. The implied black hole mass of about 10,000 solar masses is consistent with the mass–velocity dispersion relation.

    • Jong-Hak Woo
    • , Hojin Cho
    • , Elena Gallo
    • , Edmund Hodges-Kluck
    • , Huynh Anh N. Le
    • , Jaejin Shin
    • , Donghoon Son
    •  & John C. Horst
  • Letter |

    Two Hα emission peaks are detected within the disk of the T Tauri star PDS 70: one corresponds to protoplanet PDS 70 b, and the other is associated with a second accreting planet of few Jupiter masses at ~35 au. The two protoplanets are near 2:1 mean motion resonance, supporting migration scenarios of giant planets during planetary formation.

    • S. Y. Haffert
    • , A. J. Bohn
    • , J. de Boer
    • , I. A. G. Snellen
    • , J. Brinchmann
    • , J. H. Girard
    • , C. U. Keller
    •  & R. Bacon
  • Letter |

    Chandra X-ray Observatory spectral observations of the active star HR 9024 provide evidence of plasma motions that indicate a stellar flare and subsequent coronal mass ejection. This event provides critical information on non-solar coronal mass ejections and a point of comparison to the Sun, a much less active star.

    • C. Argiroffi
    • , F. Reale
    • , J. J. Drake
    • , A. Ciaravella
    • , P. Testa
    • , R. Bonito
    • , M. Miceli
    • , S. Orlando
    •  & G. Peres
  • Letter |

    A systematic change in Jupiter’s magnetic field can be detected by collating all data obtained in the last 45 years by multiple spacecraft, from Pioneer 10 to Juno. Such variation can be attributed to the zonal winds, which advect the magnetic field from the deep atmospheric layers.

    • K. M. Moore
    • , H. Cao
    • , J. Bloxham
    • , D. J. Stevenson
    • , J. E. P. Connerney
    •  & S. J. Bolton
  • Letter |

    PlanetNet, a new deep learning algorithm, can quickly and accurately map spatial and spectral features across large, heterogeneous areas of a planet. The major components of the 2008 storm on Saturn are delineated, indicating regions to be probed more deeply with radiative transfer models.

    • I. P. Waldmann
    •  & C. A. Griffith
  • Letter |

    Carbon-rich and oxygen-rich material coexist in a presolar grain originated by an outburst of a CO nova and found within the LaPaz Icefield 031117 meteorite. Condensation of both carbon and oxygen can thus happen in the same circumstellar environment, contrary to previous assumptions.

    • Pierre Haenecour
    • , Jane Y. Howe
    • , Thomas J. Zega
    • , Sachiko Amari
    • , Katharina Lodders
    • , Jordi José
    • , Kazutoshi Kaji
    • , Takeshi Sunaoshi
    •  & Atsushi Muto
  • Letter |

    The Milky Way is thought to have accreted dwarf galaxies and their stellar content. Here, Xing et al. study a Galactic halo star enhanced in r-process elements and depleted in α-elements, indicating that it likely formed in a recently accreted dwarf galaxy similar to Ursa Minor.

    • Qian-Fan Xing
    • , Gang Zhao
    • , Wako Aoki
    • , Satoshi Honda
    • , Hai-Ning Li
    • , Miho N. Ishigaki
    •  & Tadafumi Matsuno
  • Letter |

    Three mysterious features at Titan’s northern polar region appear as lakes when observed with Cassini’s radar during winter but as land when observed in the infrared during spring, providing evidence of liquid removal on Titan at seasonal scale.

    • Shannon M. MacKenzie
    • , Jason W. Barnes
    • , Jason D. Hofgartner
    • , Samuel P. D. Birch
    • , Matthew M. Hedman
    • , Antoine Lucas
    • , Sebastien Rodriguez
    • , Elizabeth P. Turtle
    •  & Christophe Sotin
  • Letter |

    Molecular emission lines originating in Titan’s relatively unexplored upper mesosphere and thermosphere reveal a strong prograde jet that reaches speeds of 340 m s–1 at 1,000 km altitude.

    • E. Lellouch
    • , M. A. Gurwell
    • , R. Moreno
    • , S. Vinatier
    • , D. F. Strobel
    • , A. Moullet
    • , B. Butler
    • , L. Lara
    • , T. Hidayat
    •  & E. Villard
  • Letter |

    Using large-aperture Cherenkov telescopes, Benbow et al. have measured the angular sizes of two stars through timely occultations by asteroids, achieving an order of magnitude improvement in resolution over the lunar occultation method.

    • W. Benbow
    • , R. Bird
    • , A. Brill
    • , R. Brose
    • , A. J. Chromey
    • , M. K. Daniel
    • , Q. Feng
    • , J. P. Finley
    • , L. Fortson
    • , A. Furniss
    • , G. H. Gillanders
    • , C. Giuri
    • , O. Gueta
    • , D. Hanna
    • , J. P. Halpern
    • , T. Hassan
    • , J. Holder
    • , G. Hughes
    • , T. B. Humensky
    • , A. M. Joyce
    • , P. Kaaret
    • , P. Kar
    • , N. Kelley-Hoskins
    • , M. Kertzman
    • , D. Kieda
    • , M. Krause
    • , M. J. Lang
    • , T. T. Y. Lin
    • , G. Maier
    • , N. Matthews
    • , P. Moriarty
    • , R. Mukherjee
    • , D. Nieto
    • , M. Nievas-Rosillo
    • , S. O’Brien
    • , R. A. Ong
    • , N. Park
    • , A. Petrashyk
    • , M. Pohl
    • , E. Pueschel
    • , J. Quinn
    • , K. Ragan
    • , P. T. Reynolds
    • , G. T. Richards
    • , E. Roache
    • , C. Rulten
    • , I. Sadeh
    • , M. Santander
    • , G. H. Sembroski
    • , K. Shahinyan
    • , I. Sushch
    • , S. P. Wakely
    • , R. M. Wells
    • , P. Wilcox
    • , A. Wilhelm
    • , D. A. Williams
    •  & T. J. Williamson
  • Letter |

    An intensification of the 7.8-µm methane emission at Jupiter’s poles is observed in coincidence with the arrival of a solar-wind compression in January 2017, highlighting the strong coupling between Jupiter’s magnetosphere and its neutral stratosphere.

    • J. A. Sinclair
    • , G. S. Orton
    • , J. Fernandes
    • , Y. Kasaba
    • , T. M. Sato
    • , T. Fujiyoshi
    • , C. Tao
    • , M. F. Vogt
    • , D. Grodent
    • , B. Bonfond
    • , J. I. Moses
    • , T. K. Greathouse
    • , W. Dunn
    • , R. S. Giles
    • , F. Tabataba-Vakili
    • , L. N. Fletcher
    •  & P. G. J. Irwin
  • Letter |

    High-precision polarization observations of the binary star system Spica reveal that the amount of light from the primary component that is reflected off the secondary component (and vice versa) is a few per cent of the incident light. Such observations will be useful in identifying close binary systems.

    • Jeremy Bailey
    • , Daniel V. Cotton
    • , Lucyna Kedziora-Chudczer
    • , Ain De Horta
    •  & Darren Maybour
  • Letter |

    There are three different evolutionary pathways leading to post-starburst galaxies in the EAGLE simulations, all consistent with observationally motivated scenarios. These multiple pathways explain the observational diversity of post-starburst galaxies.

    • M. M. Pawlik
    • , S. McAlpine
    • , J. W. Trayford
    • , V. Wild
    • , R. Bower
    • , R. A. Crain
    • , M. Schaller
    •  & J. Schaye
  • Letter |

    High-angular-resolution observations of 1.3 mm continuum and H30α recombination line emission identify a binary star system in formation, with protostars apparently separated by 180 au. The velocity difference between the two protostars constrains the orbital period and total mass of the system.

    • Yichen Zhang
    • , Jonathan C. Tan
    • , Kei E. I. Tanaka
    • , James M. De Buizer
    • , Mengyao Liu
    • , Maria T. Beltrán
    • , Kaitlin Kratter
    • , Diego Mardones
    •  & Guido Garay
  • Letter |

    Jupiter’s magnetic field can affect the circulation of the internal ocean of Europa and possibly of other Jovian moons by generating a Lorentz force in the ocean’s salty water. Such a force creates an equatorial jet that affects the ocean’s dynamics and acts as a torque on Europa’s ice shell, possibly affecting its surface features.

    • Christophe Gissinger
    •  & Ludovic Petitdemange
  • Letter |

    A single gravitational-wave measurement, for example of extreme-mass ratio inspirals by LISA, can be used to verify the existence of light bosons by model selection, rule out alternative explanations for the signal and measure the boson mass.

    • Otto A. Hannuksela
    • , Kaze W. K. Wong
    • , Richard Brito
    • , Emanuele Berti
    •  & Tjonnie G. F. Li
  • Letter |

    In this work, more than fifty late-time nebular spectra of stripped-envelope supernovae are studied in order to understand more about the massive-star progenitors of these objects. Type Ib and IIb progenitors are largely indistinguishable; type Ic progenitors likely have more massive carbon–oxygen cores.

    • Qiliang Fang
    • , Keiichi Maeda
    • , Hanindyo Kuncarayakti
    • , Fengwu Sun
    •  & Avishay Gal-Yam
  • Letter |

    Compact exoplanetary systems frequently experience spin–orbit coupling driven by secular resonances, which can shape their architecture, allowing the planet to maintain a large obliquity and inducing the piling up of planets just wide of the first-order resonance.

    • Sarah Millholland
    •  & Gregory Laughlin
  • Letter |

    Farside solar magnetograms are generated from STEREO images using deep learning, with Hale-patterned active regions being well reproduced. These images can be used to monitor the temporal evolution of magnetic fields from the farside to the frontside.

    • Taeyoung Kim
    • , Eunsu Park
    • , Harim Lee
    • , Yong-Jae Moon
    • , Sung-Ho Bae
    • , Daye Lim
    • , Soojeong Jang
    • , Lokwon Kim
    • , Il-Hyun Cho
    • , Myungjin Choi
    •  & Kyung-Suk Cho
  • Letter |

    The decades-old concept of a ‘superwind’ may not apply to extreme oxygen-rich asymptotic giant branch stars since a shell of enhanced circumstellar density (mimicking a superwind) can be produced through binary interaction rather than mass loss.

    • L. Decin
    • , W. Homan
    • , T. Danilovich
    • , A. de Koter
    • , D. Engels
    • , L. B. F. M. Waters
    • , S. Muller
    • , C. Gielen
    • , D. A. García-Hernández
    • , R. J. Stancliffe
    • , M. Van de Sande
    • , G. Molenberghs
    • , F. Kerschbaum
    • , A. A. Zijlstra
    •  & I. El Mellah
  • Letter |

    The initial abundance of 26Al in a planetary system determines the surface environment of its solid planets. High levels of 26Al will dehydrate planetesimals and produce water-poor worlds similar to the terrestrial planets in our Solar System; sub-solar levels of 26Al will preferentially generate ocean planets.

    • Tim Lichtenberg
    • , Gregor J. Golabek
    • , Remo Burn
    • , Michael R. Meyer
    • , Yann Alibert
    • , Taras V. Gerya
    •  & Christoph Mordasini
  • Letter |

    Kepler-107 b and c have the same radius but, contrary to expectations, the outermost Kepler-107 c is much denser. This difference cannot be explained by photoevaporation by stellar high-energy particle flux and it suggests that Kepler-107 c experienced a giant impact event.

    • Aldo S. Bonomo
    • , Li Zeng
    • , Mario Damasso
    • , Zoë M. Leinhardt
    • , Anders B. Justesen
    • , Eric Lopez
    • , Mikkel N. Lund
    • , Luca Malavolta
    • , Victor Silva Aguirre
    • , Lars A. Buchhave
    • , Enrico Corsaro
    • , Thomas Denman
    • , Mercedes Lopez-Morales
    • , Sean M. Mills
    • , Annelies Mortier
    • , Ken Rice
    • , Alessandro Sozzetti
    • , Andrew Vanderburg
    • , Laura Affer
    • , Torben Arentoft
    • , Mansour Benbakoura
    • , François Bouchy
    • , Jørgen Christensen-Dalsgaard
    • , Andrew Collier Cameron
    • , Rosario Cosentino
    • , Courtney D. Dressing
    • , Xavier Dumusque
    • , Pedro Figueira
    • , Aldo F. M. Fiorenzano
    • , Rafael A. García
    • , Rasmus Handberg
    • , Avet Harutyunyan
    • , John A. Johnson
    • , Hans Kjeldsen
    • , David W. Latham
    • , Christophe Lovis
    • , Mia S. Lundkvist
    • , Savita Mathur
    • , Michel Mayor
    • , Giusi Micela
    • , Emilio Molinari
    • , Fatemeh Motalebi
    • , Valerio Nascimbeni
    • , Chantanelle Nava
    • , Francesco Pepe
    • , David F. Phillips
    • , Giampaolo Piotto
    • , Ennio Poretti
    • , Dimitar Sasselov
    • , Damien Ségransan
    • , Stéphane Udry
    •  & Chris Watson
  • Letter |

    An outburst from young star V883 Ori has vaporized much of the ice inventory of its protoplanetary disk, uniquely revealing a rich organic chemistry involving several complex molecules.

    • Jeong-Eun Lee
    • , Seokho Lee
    • , Giseon Baek
    • , Yuri Aikawa
    • , Lucas Cieza
    • , Sung-Yong Yoon
    • , Gregory Herczeg
    • , Doug Johnstone
    •  & Simon Casassus
  • Letter |

    Using precise distances to more than 1,300 classical Cepheids, Chen et al. have traced the warp of the Milky Way’s stellar disk to beyond 20 kpc. The Galaxy’s warp likely arose due to the torques exerted by its massive inner disk.

    • Xiaodian Chen
    • , Shu Wang
    • , Licai Deng
    • , Richard de Grijs
    • , Chao Liu
    •  & Hao Tian
  • Letter |

    Using a pair of modest telescopes, Arimatsu et al. have observed an occultation event that purports to have been caused by a kilometre-sized Kuiper belt object (KBO). KBOs of this order of magnitude in size have not been detected before, but are likely to represent the most populous size of object in the Kuiper belt.

    • K. Arimatsu
    • , K. Tsumura
    • , F. Usui
    • , Y. Shinnaka
    • , K. Ichikawa
    • , T. Ootsubo
    • , T. Kotani
    • , T. Wada
    • , K. Nagase
    •  & J. Watanabe
  • Letter |

    The distance of outflowing gas from the galaxy centre for 915 quasars is found to be typically tens of parsecs. Typical outflow mass rates and energies indicate that these outflows are energetic enough to influence the evolution of their host galaxies.

    • Zhicheng He
    • , Tinggui Wang
    • , Guilin Liu
    • , Huiyuan Wang
    • , Weihao Bian
    • , Kirill Tchernyshyov
    • , Guobin Mou
    • , Youhua Xu
    • , Hongyan Zhou
    • , Richard Green
    •  & Jun Xu
  • Letter |

    The concordance cosmology model is poorly tested at high redshifts. Here the expansion rate of the Universe in the range 0.5 < z < 5.1 is measured based on a Hubble diagram of quasars, whose distances are estimated from their X-ray and ultraviolet emission.

    • G. Risaliti
    •  & E. Lusso
  • Letter |

    Using SN 1987A as a cosmic laboratory, Miceli et al. have measured the shock acceleration of ions heavier than oxygen, finding that the post-shock temperature of a wide range of ions is mass dependent.

    • Marco Miceli
    • , Salvatore Orlando
    • , David N. Burrows
    • , Kari A. Frank
    • , Costanza Argiroffi
    • , Fabio Reale
    • , Giovanni Peres
    • , Oleh Petruk
    •  & Fabrizio Bocchino
  • Letter |

    ALMA observations of well-studied quadruple stellar system HD 98800 have revealed the presence of a circumbinary disk in a polar orientation around one of the binary pairs, providing observational confirmation of the theoretical stability of such an arrangement.

    • Grant M. Kennedy
    • , Luca Matrà
    • , Stefano Facchini
    • , Julien Milli
    • , Olja Panić
    • , Daniel Price
    • , David J. Wilner
    • , Mark C. Wyatt
    •  & Ben M. Yelverton
  • Letter |

    Increased UV–optical nuclear emission in a nearby galaxy together with a spectrum showing emission lines typical of unobscured AGNs and Bowen fluorescence features suggests a longer-term event of intensified accretion onto the central supermassive black hole.

    • Benny Trakhtenbrot
    • , Iair Arcavi
    • , Claudio Ricci
    • , Sandro Tacchella
    • , Daniel Stern
    • , Hagai Netzer
    • , Peter G. Jonker
    • , Assaf Horesh
    • , Julián Esteban Mejía-Restrepo
    • , Griffin Hosseinzadeh
    • , Valentina Hallefors
    • , D. Andrew Howell
    • , Curtis McCully
    • , Mislav Baloković
    • , Marianne Heida
    • , Nikita Kamraj
    • , George Benjamin Lansbury
    • , Łukasz Wyrzykowski
    • , Mariusz Gromadzki
    • , Aleksandra Hamanowicz
    • , S. Bradley Cenko
    • , David J. Sand
    • , Eric Y. Hsiao
    • , Mark M. Phillips
    • , Tiara R. Diamond
    • , Erin Kara
    • , Keith C. Gendreau
    • , Zaven Arzoumanian
    •  & Ron Remillard