Stars and Galaxies, Vol. 05 (2022年)


Astronomical Observations at Nagashima-Aiseien, a Hansen’s diseasesanatorium
1) 京都市立芸術大学
2) 京都大学宇宙総合学研究ユニット
1) aculty of Fine Arts, Kyoto City University of Art
2) Unit of Synergetic Studies for Space, Kyoto University
Received 2021 December 28; Accepted 2022 May 10


This paper presents the history and observational records of Nagashima Astronomical Observatoryestablished in 1949 at Nagashima Aiseien, a national sanatorium for Hansen’s disease in Japan. Theobservatory was a part of the meteorological observatory of the sanatorium, and the observers, who werealso Hansen’s disease patients, conducted regular sunspot observations and occasional stellar occultations.The observatory also provided residents and staff of the sanatorium with opportunities to enjoy watchingstars. Two astronomers outside the sanatorium deeply committed to the foundation and observations atthe Nagashima Observatory: Issei Yamamoto, the first director of Kyoto University’s Kwasan Observatory,and Minoru Honda, known for his discoveries of comets and novas. The records of sunspot and occultationobservations were sent to Yamamoto as well as to the Tokyo Astronomical Observatory (Today’s NationalAstronomical Observatory of Japan) . The significance and uniqueness of the astronomical observationsat Nagashima Observatory are discussed from the perspectives of amateur astronomy and the history ofHansen’s disease sanatoria.

 Key words:sunspots, lunar occultation, amateur astronomy, Hansen’s disease
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Launch and management of an astronomy laboratory at Tokyo Denki University
Author:Aya E. HIGUCHI
Affiliation : Division of Science, School of Science and Engineering, Tokyo Denki University, Ishizaka, Hatoyama-machi, Hiki-gun, Saitama 350-0394, Japan
Received 2022 October 24; Accepted 2022 November 28


The astronomy laboratory of the School of Science and Engineering, Tokyo Denki University is newly estab-lished in April 2021. Since this is the first laboratory to work on astronomy at our university, we have been conduct-ing management while exploring the direction of research and education style. Here, we present the current statusof our activities and then discuss education by using astronomy at universities.

 Key words:radio astronomy — optical astronomy — education
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Confirmation of Geminid meteor parameters via simultaneous 3-point radioobservations of meteor head echoes using VHF ham radio wavesand low-powered ham devices
著者:鈴木和博1, 2, 加藤泰男3, 岡本貞夫4
1) 星城高校 〒470-1161 愛知県豊明市栄町新左山20
2) 豊橋工科高校 〒441-8141 愛知県豊橋市草間町官有地
3) 名古屋大学宇宙地球環境研究所豊川分室 〒442-0061 愛知県豊川市穂ノ原3丁目13
4) 日本流星研究会
Authors:azuhiro SUZUKI1, 2, Yasuo KATOH3, and Sadao OKAMOTO4
Affiliation: 1) Seijoh High School, Sakae-cho, Toyoake, Aichi, 470-1161, Japan
2) Toyohashi High School of Technology, Kusama-cho, Toyohashi, Aichi, 441-8141, Japan
3) Institute for Space-Earth Environmental Research, Nagoya University, Honohara, Toyokawa, Aichi, 442-0061, Japan
4) Nippon Meteor Society
Received 2022 October 12; Accepted 2022 December 9

2021年12月13日に出現したふたご座流星群の2流星を送信点の東部20 km程度以内離れた3か所に市販のVHF受信機を設置し,10 Wで継続的に送信されたVHFハム電波の流星エコーをUSB型式で受信,周波数解析後,波形を画像化した.送信波が流星の頭部で反射された流星ヘッドエコーには流星物質がその観測速度に応じたドップラー効果を受けたドップラー周波数が確認できる.これら2流星はわが国の流星観測者ネットワークによって光学的な多点観測に成功しており,出現高度や観測速度などの種々光学的経路諸元が公開されている.筆者らは3受信点における,この2流星の電波観測によって得られた,ある時点でのドップラー周波数や,流星経路と送受信電波が直交する点(f0点)に流星頭部が到達する時刻などをフリーのFFTソフトウェアを使って詳細に解析した.その結果,電波観測データから計算・導出された電波流星の経路,観測速度などが,公表された光学的な流星経路諸元とよく一致していることが確かめられた.このことは,この流星電波観測法が昼間や天候不順時における光学的な流星観測法の代役を一部果たすことができるということを意味する.全国に何か所も観測機器を設置すれば,これまでとらえられなかった昼間や天候不順時におけるわが国への隕石落下の一部を見逃さないであろう.

Two Geminid meteor head echoes were detected simultaneously at three points on December 13, 2021, by in-stalling amateur radio receivers within approximately 20 km east from the transmitting station that was continuouslytransmitting at 10 W. The meteor echo of the VHF ham wave was received using the USB format, and the waveformwas imaged after frequency analysis. The transmission wave of the meteor head echo is reflected at the head portionof the meteor. The Doppler frequency was confirmed by subjecting the meteoroid to Doppler effect according to itsobserved velocity. These two meteors have been successfully observed at multiple points optically by the network ofmeteor researchers in Japan, and several meteor optical path parameters, such as entry angles into the atmosphere andobserved velocity, have been published. The authors analyzed the Doppler frequency of the meteor head echoes andthe time at which the meteor head reached the point where the meteor path and transmitted waves were orthogonal(f0point) by using the free FFT software. The radio meteor paths and observed velocities which were derived fromthe radio observation data were in good agreement with the published optical meteor path specifications. These find-ings indicate that this meteor radio observation method can serve as a substitute for the optical meteor observationmethod during daytime or bad weather conditions. If we install observation devices in several locations throughoutJapan, we will be able to find several meteorites falling on our country during daytime or bad weather conditions,which have been overlooked to date.

 Key words:meteor head echo — Geminid meteor — Doppler frequency — VHF ham devices
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Data Reduction Process and Pipeline for the NIC Polarimetry Mode inPython, NICpolpy
Author: Yoonsoo P.Bach1,2, Masateru Ishiguro1,2, Jun Takahashi3, and Jooyeon Geem1,2
1) Astronomy Program, Department of Physics and Astronomy, Seoul National University,Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
2) SNU Astronomy Research Center, Department of Physics and Astronomy, Seoul National University,Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
3) Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo,407–2 Nishigaichi, Sayo-cho, Hyogo 679–5313, Japan

A systematic way of data reduction for the NIC polarimetry mode has been devised and implementedto an open software calledNICpolpyin the programming language python (tested on version 3.8–3.10 asof writing). On top of the classical methods, including vertical pattern removal, a new way of diagonalpattern (Fourier pattern) removal has been implemented. Each image undergoes four reduction steps,resulting in “level 1” to “level 4” products, as well as nightly calibration frames. A simple tutorial andin-depth descriptions are provided, as well as the descriptions of algorithms. The dome flat frames (takenon UT 2020-06-03) were analyzed, and the pixel positions vulnerable to flat error were found. Using thedark and flat frames, the detector parameters, gain factor (the conversion factor), and readout noise arealso updated. We found gain factor and readout noise are likely constants over pixel or “quadrant”.

 Key words:methods: data analysis — methods: observational — techniques: image processing —techniques: polarimetric
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Precise photometry with an improved pipeline for Nayuta/NIC
Author: Tomoki Saito
Affiliation:Nishi-Harima Astronomical Observatory, Centre for Astronomy, University of Hyogo,407-2 Nishigaichi, Sayo-cho, Sayo-gun, Hyogo 679-5313, Japan

We present development of a new data reduction and analysis pipeline for Nishiharima Infrared Camera on 2 mNayuta telescope. The new pipeline includes fundamental reduction procedures, as well as miscellaneous utilitiesto prepare the calibration frames such as dark and flatfield. We improved the subtraction procedures of the detector-specific background patterns. These together improves the resulting photometric precision by a factor of∼2, whenusing the newly obtained flat frames. We also find that the photometric precision can further be improved byintroducing “ubercalibration”, resulting in the rms photometric errors of∆mag∼0.02−0.03 for 14−15 mag (AB) in H-band, under the very best condition.

 Key words:instrumentation — data analysis — near-infrared — photometry
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Pointing Correction for Nayuta Telescope Based on a Simple Analysis
Author: Jun Takahashi
Affiliation:Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo,407–2 Nishigaichi, Sayo-cho, Hyogo 679–5313, Japan
著者の電子メールアドレス: Received 2022 October 27; Accepted 2022 December 15


Dependence of Nayuta’s pointing errors on the telescope orientation has been analyzed using images obtainedwith NIC from 2014 to 2022. Maps of the pointing errors on the azimuth–elevation plane have been developed.It has been confirmed that pointing correction based on the maps reduces the pointing errors from46′′±19′′to15′′±8′′. The pointing correction presented here will enhance the time efficiency of observations and make theautomation easier.

Key words:Nayuta — telescopes — pointing analysis
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安政五年ドナティ彗星観測にみる土御門家の天文観測技術に関する一考察ー 江戸幕府天文方・間重遠の観測との比較から ー
Observation of Donati comet in Japan on 1858- Evaluation of the technical arts of astronomical observations atTsuchimikado (Kyoto), Tenmongata (Edo) and Hazama (Osaka) -
著者:岩橋 清美1, 北井 礼三郎2, 玉澤 春史3
1) 國學院大學 〒150-8440東京都渋谷区東4丁目10-28
2) 立命館大学 〒603-8577京都府京都市北区等持院北町56-1
3) 京都市立芸術大学 〒610-1197京都府京都市西京区大枝沓掛町13-6
Author: Kiyomi Iwahashi1, Reizaburou Kitai2, Harufumi Tamazawa3
1) Kokugakuin University, 10-28 Higashi 4-cyoume, Shibuya-ku, Tokyo 150-8440
2) Ritsumeikan University,56-1, Toujiinkita-cyou, Kita-ku, Kyoto 603-8587
3) Kyoto City University of Arts, 13-6 Kutsukake-cho, Oe, Nishikyo-ku, Kyoto 610-1197 Japan
 Received 2022 October 31; Accepted 2022 December 16


Donati comet (1858) was observed at Tsuchimikado, Tenmongata and Hazama observatories in Japan.Their daily observational records were found to give us numerical data of apparent positions of the cometand permit us to get equatorial coordinates of daily positions of the comet. Intercomparison among thethree observatories records results in the followings. (1) Japanese technological arts of the astronomicalobservation did not attained the technical levels in Western observatories yet, (2) the obtained accuraciesof the equatorial coordinates of the comet was within±2 degrees, (3) Tsuchimikado is superior to the othertwo in the viewpoint of observational accuracy, and (4) Tenmongata and Hazama equatorial coordinatesshow systematic offsets, which we can see only in the short time-spans of observation records at the twoobservatories.The three observatories had common knowledge of astronomical position measurements and utilized thesimilar instruments both in the position measurements and the time reckoning. The difference of accuraciesof measurements can be due to the setting accuracies of instruments, the robustness of the instrumentsand the human errors of the naked-eye observers.

Key words:Comet Donati - Historical records in Japan - Technical arts of observation
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Secular Variation in the Interval of Outbursts in Z Cam-type Dwarf Novae
Author: Tomohito Ohshima
Affiliation:Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo,407–2 Nishigaichi, Sayo-cho, Hyogo 679–5313, Japan
著者の電子メールアドレス: Received 2022 November 8; Accepted 2022 December 19

The secular variation in the interval of outbursts in the following six Z Cam-type dwarf novae (including thesubtype IW And-type) is investigated: Z Cam, RX And, AH Her, HL CMa, SY Cnc, and WW Cet. An analysis usingtheO−Cdiagram shows that the interval of outbursts is not steady in one system. The outburst properties beforestandstill are the decrease in outburst interval, enhancement of the magnitude in quiescence, and disappearance ofthe long outburst. Meanwhile, several objects have at least two typical intervals of outbursts. These characteristicsare difficult to be explained only by the variation in mass transfer from the secondary.

Key words:dwarf nova — variable star
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なゆたNIC近赤外線撮像観測による遠方クェーサーの変光調査 II
A study of the light variation of distant quasars by near-infrared imaging II
著者:関根章太1, 井上昭雄1,2, 斎藤智樹3, 山中郷史4, 藤本征史5, 本原顕太郎6,7, 小西真広8, 高橋英則9, 小山舜平8, 櫛引洸佑7, 吉井譲8,10, 宮田隆志8
1) 早稲田大学理工学術院先進理工学研究科物理学及応用物理学専攻, 169-8555, 東京都新宿区大久保3-4-1
2) 早稲田大学理工学術院総合研究所, 169-8555, 東京都新宿区大久保3-4-1
3) 兵庫県立大学 天文科学センター 西はりま天文台, 679-5313, 兵庫県佐用町西河内407-2
4) 鳥羽商船高等専門学校, 517-8501, 三重県鳥羽市池上町1-1
5) テキサス大学オースティン校,78705,テキサス州オースティンインナーキャンパスドライブ110
6) 自然科学研究機構国立天文台先端技術センター〒181-8588東京都三鷹市大沢2-21-1
7) 東京大学大学院理学系研究科天文学専攻〒113-0033東京都文京区本郷7-3-1
8) 東京大学大学院理学系研究科天文学教育研究センター〒181-0015東京都三鷹市大沢2-21-1
9) 東京大学大学院理学系研究科天文学教育研究センター木曽観測所〒397-0101長野県木曽郡木曽町三岳10762-30
10) アリゾナ大学スチュワード天文台, 85721,アリゾナ州タクソンノースチェリー通り933
Author: Shota Sekine1, Akio K. Inoue1,2, Tomoki Saito3, Satoshi Yamanaka4, Seiji Fujimoto5, Kentaro Motohara6,7, Masahiro Konishi8, Hidenori Takahashi9, Shuhei Koyama8, Kosuke Kushibiki7, Yuzuru Yoshii8,10, Takashi Miyata8
1Department of Physics, School of Advanced Science and Engineering, Faculty of Scinece and Engineering, Waseda University, 3-4-1 Okubo,Shinjuku-ku, Tokyo 169-8555, Japan2Waseda Research Institute for Science and Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku,Tokyo 169-8555, Japan3Nishi-Harima Astronomical Observatory, Center for Astronomy, the University of Hyogo,407–2 Nishigaichi, Sayo-cho, Hyogo 679-5313, Japan4NIT Toba Collage, 1-1 Ikegami-cho, Toba-shi, Mie 517-8501,
1) Department of Physics, School of Advanced Science and Engineering, Faculty of Scinece and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
2) Waseda Research Institute for Science and Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
3) Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo-cho, Hyogo 679-5313, Japan
4) NIT Toba Collage, 1-1 Ikegami-cho, Toba-shi, Mie 517-8501, Japan
5) Department of Astronomy, the University of Texas at Austin, 110 Inner Campus Drive, Austin, TX 78705, USA
6) Advanced Technology Center, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588, Japan
7) Department of Astronomy, Faculty of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
8) Institute of Astronomy, Faculty of Science, the University of Tokyo, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-0015, Japan
9) Kiso Observatory, Institute of Astronomy, Faculty of Science, the University of Tokyo, 10762-30 Mitake, Kiso-machi, Kiso-gun, Nagano397-0101, Japan
10) Steward Observatory, the University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85719, USA
 Received 2022 November 19; Accepted 2022 December 19

初期宇宙において,超大質量ブラックホールの形成過程は未だ解明されていない.そのため,私たちはクェーサーの変光に着目し,ブラックホールの形成について議論する.我々のグループは,なゆた望遠鏡NICを用いて,J,H,Ksの3バンド同時撮像を2019年から継続的に行なっている.2022年に観測された3つのクェーサー,PSO338+29(赤方偏移z= 6.66),ULAS J1120+0641(赤方偏移z= 7.09),ULAS J1342+0928(赤方偏移z= 7.54)について測光結果を報告する.さらに,2022年にすばる望遠鏡SWIMSで観測された,ULASJ1342+0928のJ,Ksバンドの結果も合わせて報告する.その結果として,PSO338+29のJバンドにおいて,∼2.0σ程度の変光の兆候が見られた.さらに,ULAS J1342+0928のJバンドにおいて,周期が∼102日程度の変光の可能性を指摘した.赤方偏移z∼7では,JバンドにCIV輝線が入る.そのため,周期的な変光について,CIV輝線を放射するBLR (Broad Line Region)の運動との関連性を調査した.BLRの公転周期は,∼104日程度であり,今回観測された周期とは大きく差があるため,BLRの運動とは関係ないと結論づけた.変光調査の性質上,誤差を小さくする必要性がある.ディザリング点数の変更,ubercalibrationなどの検討を行なってきたが,これまでの結果では誤差が有意に小さくなることは見られなかった.

In the early universe, the formation process of supermassive blackholes in quasars is still in debate. Our groupfocuses on the light variation of quasars and discuss this problem. We continuously observe high-zquasars inJ,H,andKsbands with Nayuta/NIC since 2019. Here we report 2022 data for three quasars, PSO338+29 (redshiftz=6.66), ULAS J1120+0641 (redshiftz= 7.09) and ULAS J1342+0928 (redshiftz= 7.54). We also reportJ,Ks bands magnitude of ULAS J1342+0928 observed with Subaru/SWIMS in 2022. PSO338+29 shows a∼2σlevel lightvariation in theJband. ULAS J1342+0928 shows a sign of∼102days periodic variation in theJband. At redshiftz∼7, the CIVemission line comes into theJband. Hence, we discuss the relation between periodic motion ofBLR (Broad Line Region) to this variability period. The orbital period of BLR is∼104days. We conclude that theBLR motion is not responsible to this periodic variability. It is important to reduce the magnitude uncertainty for thevariability research. We have examined the magnitude uncertainties when adopting different numbers of ditheringpoints and ubercalibration. However, any significant reduction of the uncertainties was not observed.

 Key words:quasars: supermassive black holes
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Disk structure of Be stars Monitoring the equivalent width of the hydrogenemission lines and the Balmer decrement
Authors:Mitsuhiro Ishida
Affiliation:okohama Municipal Totsuka High School, 2–27–1 Gumizawa, Totsuka-ku, Yokohama-shi, Kanagawa 245–0061, Japan
Received 2022 October 31; Accepted 2022 December 21

長年、Be星(カシオペヤ座γ型変光星)の測光・分光観測が行われているが、未だに星周円盤の生成・消滅のメカニズムは明らかになっていない。そこで、2018年9月から2020年3月まで、学校天文台にある小口径望遠鏡+低分散分光器を用いて、複数のBe星の分光モニター観測を行った。得られたスペクトルから水素輝線等価幅、バルマー逓減率(Hα/ Hβ)を計算し、時間変動などを調べた。その結果、バルマー逓減率に有意な変動がある天体を複数確認した。この現象を説明するため、「Be星の伴星が近星点を通過するときの潮汐力で円盤がリング化する」という仮説を立てた。

For many years, photometric and spectroscopic observations of Be stars (γ-type variable stars in Cassiopeia)have been carried out, but the mechanism of the formation and extinction of the circumstellar disk is still unclear.Therefore, from September 2018 to March 2020, we performed spectroscopic monitoring observations of severalBe stars using the Small Aperture Telescope + Low Dispersion Spectrograph at the School Observatory. From theobtained spectra, we calculated the hydrogen emission line equivalent widths and Balmer decrement (Hα/ Hβ), andinvestigated the time variability and so on. As a result, we identified several sources with significant variations in theBalmer decrement. To explain this phenomenon, we hypothesized that the disk is ringed by the tidal force of Be’scompanion star as it passes the perihelion point.

 Key words:emission-line—Be Star
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