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The First VERA Astrometry Catalog
Nakanishi, Hiroyuki; Hirota, Tomoya; Kurayama, Tomoharu +59 more
We present the first astrometry catalog from the Japanese VLBI (very long baseline interferometer) project VERA (VLBI Exploration of Radio Astrometry). We have compiled all the astrometry results from VERA, providing accurate trigonometric-annual-parallax and proper-motion measurements. In total, 99 maser sources are listed in the VERA catalog. Am…
Elemental abundances of M dwarfs based on high-resolution near-infrared spectra: Verification by binary systems
Kuzuhara, Masayuki; Omiya, Masashi; Reiners, Ansgar +4 more
M dwarfs are prominent targets of planet search projects, and their chemical composition is crucial to understanding the formation process or interior of orbiting exoplanets. However, measurements of elemental abundances of M dwarfs have been limited due to difficulties in the analysis of their optical spectra. We conducted a detailed chemical ana…
Gaia's detectability of black hole-main sequence star binaries formed in open clusters
Fujii, Michiko S.; Kumamoto, Jun; Shikauchi, Minori +1 more
Black hole-main sequence star (BH-MS) binaries are one of the targets of future data releases of the astrometric satellite Gaia. They are supposed to be formed in two main sites: a galactic field and star clusters. However, previous work has never predicted the number of BH-MS binaries originating in the latter sites. In this paper we estimate the…
Annual parallax measurement of the Mira variable star BX Camelopardalis with VERA
Kurayama, Tomoharu; Honma, Mareki; Nakagawa, Akiharu +8 more
We report the results of astrometric VLBI observations toward the Mira variable star BX Cam using the VERA VLBI array. The observation was performed from 2012 February to 2014 November. The parallax obtained is 1.73 ± 0.03 mas corresponding to a distance of 0.58 ± 0.01 kpc. The parallax of this source was reported in Gaia DR2 as 4.13 ± 0.25 mas, a…
Distribution of physical parameters for 380 contact binaries in the Kepler field
Zhu, Li-Ying; Liu, Liang; Li, Xu-Zhi
We present the physical parameters (p, T, q, i, f) of 380 Kepler contact binary systems (hereafter called CBs). A statistical study on the CBs is carried out based on a Kepler photometric database. Our samples were selected from the Kepler Eclipsing Binary Catalogue of EW-type eclipsing binaries with periods around 0.2-1 d and amplitudes greater t…
First detection of two superoutbursts during the rebrightening phase of a WZ Sge-type dwarf nova: TCP J21040470+4631129
Ruiz, Javier; Nogami, Daisaku; Tamura, Motohide +51 more
We report on photometric and spectroscopic observations and analysis of the 2019 superoutburst of TCP J21040470+4631129. This object showed a 9 mag superoutburst with early superhumps and ordinary superhumps, which are the features of WZ Sge-type dwarf novae. Five rebrightenings were observed after the main superoutburst. The spectra during the po…
Comprehensive photometric investigation of an active early K-type contact system—IL Cancri
Sarotsakulchai, Thawicharat; Liu, Nian-Ping; Rattanasoon, Somsawat +1 more
Comprehensive photometric investigation of the early K-type contact binary IL Cnc was carried out. A few light curves from both ground-based telescopes and the Kepler space telescope were obtained (or downloaded) and then analyzed in detail. They are mostly found to be asymmetric and there are even continuously changing O'Connell effects in the li…
TESS photometry of the eclipsing δ Scuti star AI Hydrae
Kristiansen, Martti H.; Hong, Kyeongsoo; Lee, Jae Woo
AI Hya has been known as an eclipsing binary with a monoperiodic $\delta$ Sct pulsator. We present the results from its TESS (Transiting Exoplanet Survey Satellite) photometry observed during Sector 7. Including our five minimum epochs, the eclipse timing diagram displays the apsidal motion with a rate of $\dot{\omega } = 0.075 \pm 0.031\:$ deg $\…
Trigonometric parallax of O-rich Mira variable star OZ Gem (IRAS 07308+3037): A confirmation of the difference between the P-L relations of the Large Magellanic Cloud and the Milky Way
Kawabata, Koji; Fujimoto, Masayuki Y.; Yamanaka, Masayuki +11 more
OZ Geminorum (OZ Gem) is a galactic Mira variable in the Milky Way (MW). We measured its annual parallax with VLBI Exploration of Radio Astrometry to be π = 0.806 ± 0.039 mas, corresponding to a distance of D = 1.24 ± 0.06 kpc. Based on multi-epoch infrared observations with the Kagoshima University 1 m telescope, we also derived the mean J-, H-, …
ALMA twenty-six arcmin2 survey of GOODS-S at one millimeter (ASAGAO): Millimeter properties of stellar mass selected galaxies
Ouchi, Masami; Fujimoto, Seiji; Tamura, Yoichi +19 more
We make use of the ALMA twenty-Six Arcmin2 survey of GOODS-S At One-millimeter (ASAGAO), deep 1.2 mm continuum observations of a 26-arcmin2 region in the Great Observatories Origins Deep Survey-South (GOODS-S) obtained with Atacama Large Millimeter/sub-millimeter Array (ALMA), to probe dust-enshrouded star formation in K-band…