340 citations · 1.8k across the 78 of their papers we have counts for
78 papers
SN 2023gfo: A Peculiar Type IIP Supernova with High Luminosity and Normal Plateau Duration
Riko Namba, Masayuki Yamanaka, Keiichi Maeda +9
We present near-infrared (NIR) and optical observations of the highly reddened Type IIP supernova (SN) 2023gfo in the nearby galaxy NGC 4995 ( Mpc), which reached…
Two years of shock interaction tracing three phases of evolution: the explosion of a Type IIn supernova, SN 2019vxm
Gitika Rameshan, Rishabh Singh Teja, D. K. Sahu +10
We present multi-wavelength photometric and optical spectroscopic observations of the long-lived interacting supernova SN 2019vxm, spanning more than two years after the explosion.…
SN 2024dy: Dust formation in a long-lived Type IIn supernova and constraints on the dust mass
Sota Goto, Masayuki Yamanaka, Koji S. Kawabata +10
Type~IIn supernovae (SNe) are a subclass of core-collapse SNe powered by interaction between the ejecta and the dense circumstellar material. Among them, long-lived Type~IIn events…
A growth of early superhump: Multi color observation of the WZ Sge star TCP J23580961+5502508
Ryosuke Sazaki, Makoto Uemura, Tatsuya Nakaoka +1
We report optical and near-infrared photometry of a WZ Sge-type dwarf nova, TCP J23580961+5502508, during its 2022 superoutburst, obtained using the 1.5-m Kanata telescope. Our obs…
Tracking down the broadband polarimetric properties of PG 1553+113
Riccardo Middei, Svetlana G. Jorstad, Alan P. Marscher +78
We report on a nine-month monitoring campaign of the blazar PG 1553+113, relying on three observations carried out in 2025 with the Imaging X-ray Polarimetry Explorer (IXPE) and su…
One-week optical observations of pulsed emission from the Crab pulsar with IMONY on the 3.8 m Seimei telescope
Kazuaki Hashiyama, Takeshi Nakamori, Anju Sato +13
We report our optical observations of the Crab pulsar using the Imager of MPPC-based Optical photoN counter from Yamagata (IMONY), a high-time-resolution photon-counting imager wit…
The IXPE and multifrequency polarimetric view of the extreme blazars 1ES 1101-232 and RGB J0710+591
Fabrizio Tavecchio, Dawoon E. Kim, Gabriel Emery +53
Multiwavelength polarimetry is a powerful tool to probe magnetic field and flow geometries in the relativistic jets of blazars. In this respect, particularly interesting are the so…
Near-infrared [P II] and [Fe II] line mapping of Galactic supernova remnants
Takuma Kokusho, Yuki Katsurada, Yong-Hyun Lee +7
Phosphorus (P) is one of the key ingredients for life, yet its origins in galaxies remain poorly understood. In order to investigate the production of P by supernovae, we performed…
Identifying the secondary jet in the RadioAstron image of OJ~287
Mauri J. Valtonen, Lankeswar Dey, Staszek Zola +26
The 136 year long optical light curve of OJ~287 is explained by a binary black hole model where the secondary is in a 12 year orbit around the primary. Impacts of the secondary on…
Unveiling blazar synchrotron emission: a multiwavelength polarimetric study of HSP and LSP populations
Sara Capecchiacci, Ioannis Liodakis, Riccardo Middei +96
Polarimetric properties of blazars allow us to put constraints on the acceleration mechanisms that fuel their powerful jets. By studying the multiwavelength polarimetric behaviour…
Magnetic field of a ring-like shape molecular cloud
Dana Alina, Adel Umirbayeva, Yasuo Doi +13
We present a detailed study of the magnetic field structure in the G111 molecular cloud, a ring-like filamentary cloud within the NGC 7538 region. We utilized interstellar dust pol…
SN 2023xgo: Helium-rich Type Icn or Carbon-Flash Type Ibn supernova?
Anjasha Gangopadhyay, Jesper Sollerman, Konstantinos Tsalapatas +35
We present observations of SN~2023xgo, a transitional Type Ibn/Icn supernova, from to ~days relative to the -band peak. Early spectra show C~III emission rem…
Optical photon-counting observation of the Crab pulsar with Kanata telescope using prototype IMONY
Takeshi Nakamori, Kazuaki Hashiyama, Rin Sato +14
We have developed an optical photon-counting imaging system, IMONY, as an instrument for short-scale time-domain astronomy. In this study, we utilized a Geiger avalanche photodiode…
Smart Kanata: A Framework for Autonomous Decision Making in Rapid Follow-up Observations of Cataclysmic Variables
Makoto Uemura, Yuzuki Koga, Ryosuke Sazaki +11
Studying the early stages of transient events provides crucial information about the fundamental physical processes in cataclysmic variables (CVs). However, determining an appropri…
A Two-Week Monitoring Campaign on Mrk 421
W. Peter Maksym, Ioannis Liodakis, M. Lynne Saade +153
X-ray polarization is a unique new probe of the particle acceleration in astrophysical jets made possible through the Imaging X-ray Polarimetry Explorer. Here we report on the firs…
SN 2021foa: the bridge between SN IIn and Ibn
Anjasha Gangopadhyay, Naveen Dukiya, Takashi J Moriya +26
We present the long-term photometric and spectroscopic analysis of a transitioning SN~IIn/Ibn from 10.8 d to 150.7 d post -band maximum. SN~2021foa shows prominent He {\sc i}…
MASTER OT J030227.28+191754.5: an unprecedentedly energetic dwarf nova outburst
Yusuke Tampo, Taichi Kato, Keisuke Isogai +60
We present a detailed study of the MASTER OT J030227.28+191754.5 outburst in 2021-2022, reaching an amplitude of 10.2 mag and a duration of 60 d. The detections of (1) the double-p…
X-ray and multiwavelength polarization of Mrk 501 from 2022 to 2023
Chien-Ting J. Chen, Ioannis Liodakis, Riccardo Middei +143
We present multiwavelength polarization measurements of the luminous blazar Mrk~501 over a 14-month period. The 2--8 keV X-ray polarization was measured with the Imaging X-ray Pola…
IXPE observation of PKS 2155-304 reveals the most highly polarized blazar
Pouya M. Kouch, Ioannis Liodakis, Riccardo Middei +133
We report the X-ray polarization properties of the high-synchrotron-peaked (HSP) blazar PKS 2155304 based on observations with the Imaging X-ray Polarimetry Explorer (IXPE). We…
Evidence of jet activity from the secondary black hole in the OJ287 binary system
Mauri J. Valtonen, Staszek Zola, Alok C. Gupta +29
We report the study of a huge optical intraday flare on November 12, 2021, at 2 am UT, in the blazar OJ287. In the binary black hole model it is associated with an impact of the se…
Unravelling the asphericities in the explosion and multi-faceted circumstellar matter of SN 2023ixf
Avinash Singh, R. S. Teja, T. J. Moriya +33
We present a detailed investigation of photometric, spectroscopic, and polarimetric observations of the Type II SN 2023ixf. Earlier studies have provided compelling evidence for a…
Intermediate-luminosity Type IIP SN 2021gmj: a low-energy explosion with signatures of circumstellar material
Yuta Murai, Masaomi Tanaka, Miho Kawabata +28
We present photometric, spectroscopic and polarimetric observations of the intermediate-luminosity Type IIP supernova (SN) 2021gmj from 1 to 386 days after the explosion. The peak…
Detection of X-ray Polarization from the Blazar 1ES 1959+650 with the Imaging X-ray Polarimetry Explorer
Manel Errando, Ioannis Liodakis, Alan P. Marscher +142
Observations of linear polarization in the 2-8 keV energy range with the Imaging X-ray Polarimetry Explorer (IXPE) explore the magnetic field geometry and dynamics of the regions g…
Insights into the broad-band emission of the TeV blazar Mrk 501 during the first X-ray polarization measurements
S. Abe, J. Abhir, V. A. Acciari +260
We present the first multi-wavelength study of Mrk 501 including very-high-energy (VHE) gamma-ray observations simultaneous to X-ray polarization measurements from the Imaging X-ra…