activity
20062021
most citedA Unicorn in Monoceros: the dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate

117 citations · 899 across the 70 of their papers we have counts for

collaborators

72 papers

astro-ph.SR2021

A survey for variable young stars with small telescopes: V - Analysis of TXOri, V505Ori, and V510Ori, the HST ULLYSES targets in the Ori cluster

Dirk Froebrich, Jochen Eislöffel, Bringfried Stecklum +2

Investigations of the formation of young stellar objects (YSOs) and planets require the detailed analysis of individual sources as well as statistical analysis of a larger number o…

astro-ph.SR2021★ 2 cited

Orbital and spin periods of the candidate white dwarf pulsar ASASSN-V J205543.90+240033.5

Taichi Kato, Franz-Josef Hambsch, Elena P. Pavlenko +1

ASASSN-V J205543.90+240033.5 has been suggested to be a white dwarf pulsar by Kato (2021, arXiv:2108.09060). We obtained time-resolved photometry and identified the orbital and spi…

astro-ph.HE2021

Optical Variability Correlated with X-ray Spectral Transition in the Black-Hole Transient ASASSN-18ey = MAXI J1820+070

Keito Niijima, Mariko Kimura, Yasuyuki Wakamatsu +49

How a black hole accretes matter and how this process is regulated are fundamental but unsolved questions in astrophysics. In transient black-hole binaries, a lot of mass stored in…

astro-ph.SR2021★ 12 cited

On the nature of the anomalous event in 2021 in the dwarf nova SS Cygni and its multi-wavelength transition

Mariko Kimura, Shinya Yamada, Nozomi Nakaniwa +20

SS Cyg has long been recognized as the prototype of a group of dwarf novae that show only outbursts. However, this object has entered a quite anomalous event in 2021, which at firs…

astro-ph.SR2021★ 13 cited

BO Ceti: Dwarf Nova Showing Both IW And and SU UMa-Type Features

Taichi Kato, Yusuke Tampo, Naoto Kojiguchi +13

IW And stars are a recently recognized subgroup of dwarf novae which are characterized by (often repetitive) slowly rising standstills terminated by brightening, but the exact mech…

astro-ph.SR2021★ 10 cited

Spectroscopic and Photometric Observations of Dwarf Nova Superoutbursts by the 3.8 m Telescope Seimei and the Variable Star Network

Yusuke Tampo, Keisuke Isogai, Naoto Kojiguchi +59

We present spectroscopic and photometric observations of 17 dwarf-nova superoutbursts obtained by KOOLS-IFU mounted on the 3.8 m telescope Seimei at Okayama Observatory of Kyoto Un…