Solar Seminar (Zasshikai) Home Page (FY2018)


Solar Seminar (13:30-15:00 Monday, Room 504 5th floor building 4) Access

Next presenters

Date Time Section Speaker File
07-09 13:30-14:00
short
S. Okada upload or download
14:00-15:00
main
D. Seki upload or download

For Speakers
Presentation time for speaker is
main : 40 minutes as a guide, and 20 minutes discussion.
short : 20 minutes as a guide, and 10 minutes discussion.
Contents of talk are
main : about your study
short : review of recent interesting paper and share information of recent study of the Sun.
Language of slide and talks
Master cource students : Language of slide and talk could be Japanese
Doctor cource students and over : Slide must be English, and talking language could be Japanese
(If those who could not understand Japanese attend the seminar, it is preferable that you talk in English)
Title and Abstract
Please send the title and abstract of your presentation by the day before.
Presentation files
Please upload your presentation files by the start of the seminar.
If the presentation file is very big, please zip the file before uploading.
For Audiences
Honoring speakers
Plase clap your hands as a closure of a presentation to express your respection to a speaker.
For everyone
Publication sharing
Please send a copy of the submitted version of any paper on which they are working to the zasshikai mailing list just after submission
  • Useful webpage list for solar observers.
  • See also Ishii-san's Webpage and Webpage of Kwasan and Hida Observatories.

  • Main speaker
    Shibata, Ichimoto, Nagata, Ueno, Asai, Ishii, Nishida, Otsuji, Isobe,
    Kawamura, Notsu, Hirose, Denis, Kou, Sakaue, Tei, Namekata,
    Seki, Machida, Okada, Tokuda, Kihara, Kotani, Yamasaki
    Short speaker
    Shibata, Ichimoto, Nagata, Ueno, Asai, Ishii, Nishida, Otsuji, Isobe,
    Kawamura, Notsu, Hirose, Denis, Kou, Sakaue, Tei, Namekata,
    Seki, Machida, Okada, Tokuda, Kihara, Kotani, Yamasaki

    Presentations in this semester

    Date Name Title Abstract File
    04-09
    long
    K. Ichimoto Solar Projects in 2018 I will talk about the Solar-C, progress at Hide in 2017 and future plan for discussion.
    pdf
    guest
    B. Kliem Flux Rope Formation by a Confined Solar Flare Prior to a Coronal Mass Ejection We present evidence that a magnetic flux rope, observed as an extreme-ultraviolet (EUV) hot channel, was formed before a coronal mass ejection (CME) and its associated long-duration flare during a preceding confined flare in a compound event in NOAA Active Region 12371. The confined flare spawns a vertical current sheet, where magnetic reconnection creates flare ribbons and loops, a nonthermal microwave source, and a hot channel. The hot channel is strongly sigmoidal and can only be interpreted as being part of a magnetic flux rope. The reconnection during the confined flare acts like ``tether-cutting reconnection'' which enhances the flux rope and leads the region to instability. The subsequent full eruption is seen as an accelerated rise of the hot channel, the formation of a fast halo CME, and the second, long-duration flare. Such rapid formation and destabilization of a flux rope is likely of general relevance and presents a difficulty for the forecast of CMEs.
    pdf
    04-16
    long
    K. Shibata Solar Physics in Future 2018
    pdf
    04-23
    short
    K. Namekata Time Resolved Spectroscopic Observation of an M-Dwarf Flare Star EV Lac during a Flare I'll introduce the following paper:
    "Time Resolved Spectroscopic Observation of an M-Dwarf Flare Star EV Lac during a Flare"
    Honda S., Notsu, Y., Namekata K., et al. accepted to PASJ.
    https://arxiv.org/abs/1804.03771
    pptx
    main
    A. Asai Moreton Wave Observed by Hida/SMART/SDDI I would like to talk about
    "Moreton Wave Observed by Hida/SMART/SDDI"
    at the today's Taiyo-Zasshikai as a main talk.
    pdf
    04-30
    05-07
    short
    D. Seki RELATIONSHIP BETWEEN DISTRIBUTION OF MAGNETIC DECAY INDEX AND FILAMENT ERUPTIONS I will introduce the follow paper;
    "RELATIONSHIP BETWEEN DISTRIBUTION OF MAGNETIC DECAY INDEX AND FILAMENT ERUPTIONS"
    H. Li , Y. Liu , A. Elmhamdi , and A.-S. Kordi
    The Astrophysical Journal, 830:132 (8pp), 2016 October 20
    http://iopscience.iop.org/article/10.3847/0004-637X/830/2/132
    pdf
    main
    S. Ueno Investigation of long-term variations of solar activity and earth's upper atmosphere by using solar full-disk chromospheric images I would like to talk about
    "Investigation of long-term variations of solar activity and earth's upper atmosphere by using solar full-disk chromospheric images".
    For new members of our observatories, I will introduce old information
    also, such as scientific purposes, database, old results of data analysis.
    pdf
    05-14
    short
    A. Tei In today's short talk, I will mention disk counterparts
    of solar spicules referring the following three papers:
    1. "Search for high velocities in the disk counterpart of type II spicules"
    O. Langangen, B. De Pontieu, M. Carlsson, V. H. Hansteen, G. Cauzzi, & K. Reardon
    2008, ApJ, 679, L167
    http://adsabs.harvard.edu/abs/2008ApJ...679L.167L
    2. "On-disk counterparts of type II spicules in the Ca II 854.2nm and Hα lines"
    L. Rouppe van der Voort, B. De Pontieu, T. M. D. Pereira, M. Carlsson, and V. Hansteen
    2009, ApJ, 705, 272
    http://adsabs.harvard.edu/abs/2009ApJ...705..272R
    3. "Heating signatures in the disk counterparts of solar spicules in Interface Region Imaging Spectrograph observations"
    L. Rouppe van der Voort, B. De Pontieu, T. M. D. Pereira, M. Carlsson, and V. Hansteen
    2015, ApJL, 799, 3
    http://adsabs.harvard.edu/abs/2015ApJ...799L...3R
    pdf
    main
    S. Nagata
    05-21
    short
    T. Sakaue The Threatening Magnetic and Plasma Environment of the TRAPPIST-1 Planets I will introduce the following paper in the short talk of tomorrow's seminar.
    Title: The Threatening Magnetic and Plasma Environment of the TRAPPIST-1 Planets
    Author: Garraffo, Cecilia; Drake, Jeremy J.; Cohen, Ofer; Alvarado-G«Ρmez, Julian D.; Moschou, Sofia P.
    Year: 2017
    ADS: http://adsabs.harvard.edu/abs/2017ApJ...843L..33G
    pdf
    main
    K. Otsuji I would like to talk about my recent collaborative research on Kunitomo's sunspot observation in Edo era.
    Kunitomo Ikkannsai is the first Japanese man who made the Gregolian type reflective telescopes in Nagahama (Shiga pref.).
    Using his own telescope, he observed the moon, planets and the sun and drawn them by a writing brush.
    His drawings are kept by the descendants, and recently electrically scanned for scientific analysis.
    This research is carried out by the interdisciplinary team, including Kyoto, Shiga and Ibaraki univ, NAOJ, National Institute of Japanese Literature and National Institute of Polar Research.
    We performed the calibrations on the sunspot drawings of 1835-36 and reconstructed the butterfly diagram on the period, corresponding to just after the Dalton minimum (1790-1830) and the typical solar cycles restarted.
    I will introduce Kunitomo's telescope and the result of the calibrations, and discuss about the accuracy of the sunspot drawings.
    05-28
    short
    C. Denis High speed filament eruption on 2017 April 23 captured by the SMART/SDDI. In this talk I am going to introduce the observational aspects of the event, as well as the kinematic properties of the filament eruption.
    pdf
    main
    K. Nishida Factors Determining Duration of Long-Duration Events and Impulsive Flares We investigated the factors determining the durations of solar flares. By numerical simulation, we attempted to explain the durations of both long-duration events (LDEs) and impulsive flares using a unified model. By conducting 2.5-dimensional magnetohydrodynamic simulations of flares with a flux rope eruption, we investigated the dependence of the duration on the size of the inflow region for various magnetic configurations of quadrupolar loops under the flux rope as the initial conditions. The duration depended linearly on the size of the inflow region.
    pptx
    06-04
    short
    A.D. Kawamura
    main
    T.T. Ishii H-alpha Surges at the Emerging Flux Region Observed before the Pore Formation (NOAA 12660) We observed point like jets and surges at the emerging flux region before/during pore formation (NOAA 12660) on 2017-May-22(JST) with SMART/SDDI at Hida Observatory, Kyoto University.
    SMART/SDDI (Solar Dynamics DopplerImager) takes full-disk solar images with a field of view of 2520 arcsec^2 at multiple wavelengths around the H-alpha line (from 6561.9 A to 6563.7 A, with resolution of 0.25 A).
    Comparing H-alpha surge activities and magnetic field evolution using SDO/HMI data, we found following results.
    (1) At the beginning of observation (21:45UT), this region was covered by weak negative polarity.
    (2) Point like jets(surges) occurred continuously from 22:00 UT to 01:00UT.
    (3) Positive polarity flux appeared around 22:30UT.
    (4) AFS (Arch filament system) in H-alpha was seen around 03:00 UT, and pore with negative polarity was formed.
    (5) Around 05:00 UT, pore with positive polarity was formed.
    (6a) After 01:00UT, long surges occurred.
    (6b) After the formation of AFS, large surges occurred.
    This result is the first observational result with magnetic field data confirmed Kurokawa (1988 Vistas in Astronomy), the first manifestation of the emerging flux region in the solar surface is a surge activity.
    pptx
    06-11
    short
    Y.W. Huang current status of DST Horizontal Spectro-polarimeter in Hida Observatory I will talk about "current status of DST Horizontal Spectro-polarimeter in Hida Observatory", mainly the calibration accuracy and the problem we are facing with now.
    half
    S. Okada ƒvƒƒ~ƒlƒ“ƒX‚Μ‰·“x‚Ζ——¬‚ΜŠΦŒW
    pdf
    06-20
    half
    S. Tokuda ‹·‘Ρˆζƒ`ƒ…[ƒiƒuƒ‹ƒtƒBƒ‹ƒ^[‚Μ1/8 Å ƒuƒƒbƒN‚ΜŠJ”­‚ƍʑw”χΧ\‘’‚ΜŽB‘œŠΟ‘ͺ
    pdf
    half
    A. Machida SMART/SDDI‚Ι‚ζ‚ι•‚γŽ₯κ—Μˆζ‚Μ‘¬“xκ‚Μ‰πΝ
    pdf
    06-25
    short
    Y. Notsu Recent observational attempts to measure stellar winds and stellar CMEs of active stars This talk is partly motivated by Sakaue-san's recent theoretical work on M-dwarf atmosphere.
    I will briefly (quickly) mention the following papers.
    Instead of explaining each paper in detail, I try to overview the recent attempts.
    (If there are many Q&As and take long time, I will only focus on stellar winds.)

    [Stellar Winds]
    "Evidence for a Weak Wind from the Young Sun" (Wood et al. 2014 ApJL)
    http://adsabs.harvard.edu/abs/2014ApJ...781L..33W
    "New Mass-Loss Measurements from Astrospheric LyƒΏ Absorption" (Wood et al. 2005 ApJL)
    http://adsabs.harvard.edu/abs/2005ApJ...628L.143W
    "Astrospheres and Solar-like Stellar Winds" (Wood 2004 Living Review)
    http://adsabs.harvard.edu/abs/2004LRSP....1....2W
    "Radio emission and mass loss rate limits of four young solar-type stars" (Fichtinger et al. 2017)
    http://adsabs.harvard.edu/abs/2017A%26A...599A.127F

    [Stellar CMEs]
    "Constraining Stellar Coronal Mass Ejections through Multi-wavelength Analysis of the Active M Dwarf EQ Peg" (Crosley & Osten 2018 ApJ)
    http://adsabs.harvard.edu/abs/2018ApJ...856...39C
    "Investigating magnetic activity in very stable stellar magnetic fields. Long-term photometric and spectroscopic study of the fully convective M4 dwarf V374 Pegasi" (Vida et al. 2016 A&A)
    http://adsabs.harvard.edu/abs/2016A%26A...590A..11V
    pdf
    main
    H. Isobe An Intense geomagnetic storm by spotless Sun during Maunder minimum.
    pptx
    07-02
    short
    K. Hirose On Quasi-biennial Oscillations in Chromospheric Macrospicules and Their Potential Relation to the Global Solar Magnetic Field I will introduce the paper below,
    "On Quasi-biennial Oscillations in Chromospheric Macrospicules and Their Potential Relation to the Global Solar Magnetic Field"
    T. S. Kiss and R. Erdelyi
    The Astrophysical Journal, Volume 857, Issue 2, article id. 113, 9 pp. (2018)
    http://ads.nao.ac.jp/abs/2018ApJ...857..113K
    pdf
    main
    K. Namekata Emergence and Decay of Sunspots and Star spots Recently, many superflares on solar-type stars were discovered by the Kepler Space Telescope (Maehara et al. 2012). Such active stars are thought to have large star spots (Notsu et al. 2013), and superflares are considered to occur through magnetic reconnection like solar flares (Namekata et al. 2017). The emergence and decay of such large star spots are important for the understanding of superflare events as well as underlying stellar dynamo. However, there are few study which reported the temporal evolution of star spots because of its difficulty in measurements. Here, we have developed a simple method to measure temporal evolutions of star spots area with Kepler data by tracing local minima of the light curves (cf, Maehara et al. 2017). We will report the statistical properties of lifetimes, emerging and decay rates of star spots on solar-type stars. We will compare them with those of sunspots and discuss how to understand them on the basis of sunspot physics.
    pdf
    07-09
    short
    S. Okada A statistical study of transverse wave oscillations in a quiescent prominence I will introduce the following paper in the short talk of tomorrow's solar seminar.
    "A statistical study of transverse wave oscillations in a quiescent prominence"
    A. Hillier, R.J.Morton, and R.Erdelyi
    The Astrophysical Jounal Letters, 779:L16(6pp), 2013 December 20
    http://adsabs.harvard.edu/abs/2013ApJ...779L..16H
    pdf
    main
    D. Seki statistical study of the precursors of filament eruptions Filaments, the dense cooler plasmas floating in the solar corona supported by the magnetic fields, often show some activations before the eruptions. In our previous study (Seki et al. 2017 ), we quantified the filament activation prior to the eruption on 2016 November 5 03:40 UT by the standard deviation of the line-of-sight (LOS) velocity map of the filament. The LOS velocities were calculated by applying the Beckersf cloud model to 73 multi-wavelengths images around HƒΏ taken by the SDDI. As a result, we found the increase of the standard deviation prior to eruption. However, we had analyzed only one event in that study, so that it had been unclear whether the increase can be generally seen in filament eruptions.
    In this study, we surveyed 12 filaments including 2 quiescent filaments, 4 active region fila- ments, and 6 intermediate filaments in the same way as our previous work. We confirmed that in all the 12 filament disappearance events, the standard deviation increased before filaments disappeared. Moreover, we found that the time-scale of the increase is different in the types of filaments and some observational facts that possibly contribute to clarify the reason of the increase. We concluded that this quantity could probably be used as the precursor of the filament eruptions, combining it with the HƒΏ center image and the LOS velocity map.
    pdf



    Previous presentations

    2017-2nd Zasshikai Website
    Go to Zasshikai 2017-2nd
    2017-1st Zasshikai Website
    Go to Zasshikai 2017-1st
    2016 Zasshikai Website
    Go to Zasshikai 2016
    2015 Zasshikai Website
    Go to Zasshikai 2015
    All of 2014
    2014 Archive (tar.gz file, 1.9Gbyte)
    All of 2013
    2013 Archive (tar.gz file, 2.4Gbyte)
    All of 2012
    2012 Archive (tar.gz file, 780Mbyte)
    All of 2011
    2011 Archive (tar.gz file, 780Mbyte)
    All of 2010
    2010 Archive (tar.gz file, 625Mbyte)



    If there are any mistakes or errors in this webpage,
    please send e-malis to the organizer, Sakaue (sakaue_at_kwasan.kyoto-u.ac.jp).