中大及其他天文台


News

  • No recent NEWS
+ More
  • No recent recruitment announcement
Recent Research + more

  • 4U 1820-30 1987年至2023年間超軌道相位的演化

    Caption: Evolution of 4U 1820-30 superorbital phases from 1987 to 2023. The dotted, solid and dashed lines represent the best fits for linear, glitch and quadratic models, respectively. The shaded area indicates the low power state between MJD 50,773 and 52,627, and the vertical dash-dot line represents the period glitch time MJD 52,380±4145, evaluated by the glitch model, with the horizontal error bar indicating the 1σ uncertainty of the glitch time.

    Master student Jun-Lei Wu and Prof. Yi Chou studied the superorbital modulation of low mass X-ray binary 4U 1820-30.It was long believed by the astronomers that the superorbital modulation of the low-mass X-ray binary 4U 1820-30, with a period of 171 days, was a resonance effect induced by a third star orbiting the binary system—an explanation known as the triple model. The stability of this superorbital period predicted by this model is crucial for verifying this hypothesis. A research team led by Prof. Yi Chou analyzed X-ray light curves collected by six monitoring and scanning telescopes over a span of 36 years. They discovered that the superorbital period had significantly changed from 171 days to 167 days during this time. Further phase analysis revealed that this change either occurred abruptly between early 2001 and mid-2003 or evolved gradually with a period derivative of =(-4.20±0.72)x10-4 day/day. Their findings indicate that the superorbital period of 4U 1820-30 is not as stable as predicted by the triple model, strongly challenging this hypothesis. Instead, they propose an irradiation-induced mass transfer instability scenario to explain the observed superorbital modulation. The research paper has been published in the Astrophysical Journal ( Yi Chou et al. 2025 ApJ 981 43 ). Its preprint, posted on arXiv in September 2024, was reported on the renowned public outreach website Phys.org under the title "Study Inspects Unusual Behavior of an X-ray Binary" .

    Show large images and more information

  • Ia型超新星及其宿主星系,發現超新星的噴發物速度以及其生長環境可能存在著緊密的關係

    The team led by Prof. Pan investigated the relation between SN Ia ejecta velocity and their host-galaxy environment, and found that there could exist a relationship between the two parameters. This study focused on the local environmental properties of SNe Ia and revealed possible trend that high-velocity SNe Ia tend to be associated with old stellar populations, while normal-velocity SNe Ia can be found in both old and young stellar populations. This result implies that the normal SNe Ia are likely produced by more than one channel, challenging the previous consensus that they are associated with a single and uniform population. This work has been published in Lin & Pan et al., 2024, MNRAS, 531, 1988

    Show large images and more information

  • Virgo III是最新被發現的超暗矮星系(UFD)

    Virgo III is a newly discovered ultra-faint dwarf (UFD) galaxy. We used the Lulin One-meter Telescope (LOT) to search for RR Lyrae associated with this UFD.With deep exposures of LOT that can reach to r~23 mag, we discovered three RR Lyrae, labeled as V1, V2, and V3 in this deep LOT images. Using the discovered RR Lyrae, we measured a distance of 154 kpc to Virgo III.

    Show large images and more information

  • 使用泛星計畫深度巡天的數據發現Ia型超新星的性質可能隨著時間而演化

    An international team led by Prof. Pan studied the data obtained from Pan-STARRS1 Medium Deep Survey (PS1-MDS) and found the type Ia supernovae (SNe Ia) could evolve with time. As one of the most mature cosmological probes, SNe Ia have homogeneous properties, and they were expected to be consistent and similar during the evolution of our Universe. However, this work suggests that SNe Ia are likely to have at least two different populations, as separated by their ejecta velocities. The fractions between different populations tend to evolve with time. This result could impact the precision of SNe Ia in probing the cosmic expansion and dark energy. This work has been published in Pan et al., 2024, MNRAS, 532, 1887 .

    Show large images and more information

Honor+ more

  • 恭賀 本所碩士班賴品憲同學獲得 113學年度第1學期國立中央大學優秀學生獎學金 (2025-03-18)
  • 恭賀 本所鹿林天文台林宏欽台長,榮獲中央大學114年績優職員 (2025-01-21)
  • 恭賀 本所碩士班同學戴辰宇, 李孟翰及本所陳文屏教授指導本校物理系同學吳家璇榮獲2025年物理年會壁報佳作獎 (2025-01-16)
  • 恭賀 本所陳婷琬助理教授榮獲114年新聘教研人員獎勵 (2024-12-30)
  • 恭喜 本所饒兆聰教授榮獲本校114年度研究傑出獎 (2024-12-18)
  • 恭賀 本所碩士班戴辰宇同學獲得 113學年度第1學期國立中央大學優秀學生獎學金 (2024-11-14)
Academic Event

  • No Meeting & Workshop

Colloquium

  • Date: 2025-05-02
    Time: 14:00
    Location: S4-1013
    Speaker: Prof. Yu-Jung Chen
    Title: Interstellar Ice, Dust, and Energy Processing: A Laboratory Approach

Special Talk

  • Date: 2025-05-29
    Time: 12:00
    Location: S4-1013
    Speaker: Kuan-Ju Fu 傅冠儒
    Title : Career sharing session (in Mandarin)

Journal Club

  • No recent Journal Club
Visiting Scholar + more

  • Prof. Amanda Karakas (2025-05-14~2025-05-20)