天文現象及活動

朱雀橫亙東西天，井鬼柳星張翼軫 (認識中國的星官星宿，包括三垣二十八宿和四象)

活動地點：船灣淡水湖主壩
集合：下午５時３０分大埔墟火車站外近麥當勞大型廣告牌
離開船灣淡水湖主壩時間：約晚上９時正
費用：全免 (自備車資及糧草)
查詢及報名：７５８１３５４４
公共交通：
１．ＫＭＢ巴士７５Ｋ線或
２．進智公交專線小巴２０Ｃ線

【訊息由張詠倫提供】

此活動由香港觀天會主辦。

物理系學生會議：從併合中的高質量雙黑洞尋找重力波

Talk:- Searching for Gravitational Waves from the Coalescence of High Mass Black Hole Binaries

GstLAL is a search pipeline used by LIGO to search for gravitational waves from the coalescence of compact binaries (neutron stars and/or black holes), which can be operated in on-line and/or off-line configuration. Before the second observing run (O2), the parameter space covered by GstLAL consisted of binaries with component masses m1,m2 ≥ 1M⊙ (M⊙ is the solar mass) and total mass 2M⊙ ≤ M1+M2 ≤ 100M⊙. In this project, we aim to increase the upper bound of the total mass to 600M⊙ to search for gravitational waves from intermediate mass black holes (IMBH). Simulated signal injections with real noises were used to evaluate the sensitivity of GstLAL when decreasing the lower frequency cut-off to observe signals from IMBH since they merge at a lower frequency. We experimented various techniques such as different bank splitting and h(t) gating schemes to optimize the performance and sensitivity after the inclusion of IMBH signals in a search. This would enable us to detect more gravitational wave signals from the coalescence of black holes with higher masses in real time gravitational wave detection.　
　
時間：2017.05.20(六) 14:30 ~ 14:45
地點：香港中文大學 科學館LT4
講者：Ka Lok Lo
語言：英語

#131

此活動由香港中文大學物理系主辦。

喜歡星空 卻對滿天星斗非常陌生嗎？
想學習天文知識 但希望有課堂實習又有生動的講解？
很鍾情天文攝影 但想認識更多星體背後的運行和由來？
或是有志學習觀星導賞，為朋友介紹星空甚至成為本會觀星導賞義工呢？

現在機會來了！香港天文學會新一屆基礎天文班即將開班了！
本班旨在為了對觀星初學者或有志成為本會觀星導賞義工的會員，提供一個有系統的培訓。
教程由本會資深天文導師編製、修訂及監督，導師由本會委員擔任。
希望培養各學員天文興趣，教授易明而準確的天文及觀星安全知識。
這些機會你又怎能錯過？

◎實習課
時間：2017.05.20(六) 19:30 ~ 22:00
地點：(待定，另行通知)

●2017.05.27(一) 19:30 ~ 22:00

◎理論課
時間：2017.05.22(一) 19:30 ~ 21:30
地點：九龍觀塘創業街36號華基中心610室 香港天文學會會址

時間：
●2017.05.29(一) 19:30 ~ 21:30
●2017.06.05(一) 19:30 ~ 21:30
●2017.06.12(一) 19:30 ~ 21:30
●2017.06.19(一) 19:30 ~ 21:30
●2017.06.26(一) 19:30 ~ 21:30

◎筆試考核
時間：2017.07.03(一) 19:30 ~ 21:30
地點：九龍觀塘創業街36號華基中心610室 香港天文學會會址

導師：林曉怡 (學會教育部委員)
名額：16
對象：12歲或以上，有興趣觀星及認識天文的初學者，或有興趣學習觀星導賞之會員

收費課程，參加者必須報名，2017.05.01截止

此活動由香港天文學會主辦。

物理系學生會議：磁場作為恆星形成的指揮 – 一個觀測角度

Talk:- Magnetic field as a Conductor in Star Formation – An Observational Perspective

The role of the magnetic field, among other mechanisms (gravity & turbulence) in star formation remain uncertain. However, within the last decade, multi-scales observational studies have started to show that magnetic field has an important role in regulating star formation environment from Cloud through the filament to core scale and consequence star forming properties. In this presentation, we briefly review observational signatures of the dynamically important magnetic field at large/small scales. We will also briefly present multi-scale observational evidence.　
　
時間：2017.05.20(六) 14:45 ~ 15:00
地點：香港中文大學 科學館LT4
講者：
　　●Law Chi Yan
　　●Li Hua Bai
　　●Leung Po Kin
　　●Gu Qilao
　　●Zhang Yapeng
語言：英語

#131

此活動由香港中文大學物理系主辦。

喬治·菲利普斯·邦德（George Phillips Bond，1825年5月20日－1865年2月17日），美國天文學家，他的父親威廉·邦德也是一位天文學家，父子兩人共同做出了許多重要的發現。

喬治·邦德幼年時喜歡大自然和鳥類，他的父親是哈佛大學天文台的創立者和首任台長。喬治·邦德的兄長去世後，喬治·邦德覺得有義務追隨父親從事天文學工作。1848年，邦德父子發現了土衛七[1]，1850年11月，他們又共同發現了土星的第三個環——C環。英國人威廉·拉塞爾也獨立發現了土星C環和土衛七，僅比他們晚了幾天。

1847年至1852年間，邦德父子與攝影先驅約翰·亞當斯·惠普爾一起使用15英寸（0.38米）望遠鏡進行了天體照相的工作，拍攝了月亮的照片，並於1851年在英國倫敦舉辦的萬國工業博覽會上獲獎。1850年7月16日至17日夜，邦德父子和惠普爾和使用銀版照相法共同拍攝了織女星的照片，這是人類拍攝的第一張恆星的照片。1857年他們又拍攝了大熊座的開陽雙星等照片。此外，他還發現了11顆彗星，計算了它們的軌道。喬治·邦德還是第一位獲得英國皇家天文學會金質獎章的美國人。

1859年，威廉·邦德去世後，喬治·邦德接任哈佛大學天文台的台長。1865年因肺結核去世。為紀念邦德父子，第767號小行星被命名為Bondia。

【資料：維基百科 ；訊息由林景明提供】

物理系學生會議：磁場方向與恆星形成率之間的關聯

Talk:- The Link between Magnetic-Field Orientations and Star Formation Rates

Star formation rates (SFR) is a key component in modern star-formation models, which mainly involve gravity, turbulence and, in some cases, magnetic fields (B-fields). But the connection between B-fields and SFR has never been observed. A comparison between the survey of SFR and a study of cloud-field alignment – which revealed a bimodal (parallel or perpendicular) alignment – shows that clouds with lower SFR per solar mass are tend to perpendicular to the B-fields. This might be an evidence of B-fields being a primary regulator of SFR. We used B-fields data from starlight method and 353 GHz dust thermal emission, which comes from by Planck mission’s all sky survey.　
　
時間：2017.05.20(六) 15:30 ~ 15:45
地點：香港中文大學 科學館LT4
講者：GU Qilao
語言：英語

#131

此活動由香港中文大學物理系主辦。

物理系學生會議：探測中等質量黑洞的可能途徑 – 經重力透鏡效應的重力波

Talk:- A Possible Way to Probe Intermediate Mass Black Hole – Gravitational Lensing of Gravitational Wave

Existence of intermediate mass black hole is a mystery in astronomy. Theoretically it should exist, but it hasn’t been confirmed by observation yet. Since intermediate mass black hole is a possible candidate of gravitational lens, its lensing effect on gravitational wave in diffraction limit could be a direct observational evidence. Basic analysis shows the lensing effect is observable within LIGO detectability. Serious Bayesian analysis is ongoing to investigate under what circumstances we can confirm that the signal indicates an intermediate mass black hole.　
　
時間：2017.05.20(六) 15:15 ~ 15:30
地點：香港中文大學 科學館LT4
講者：Lai Kwun Hang 及 Otto Hannuksela
語言：英語

#131

此活動由香港中文大學物理系主辦。

物理系學生會議：磁場方向在絲狀雲中恆星形成率的影響

Talk:- The Effect of Magnetic Field Orientation on Star Formation Rate in Filament Clouds

With the rapid growth of computational power, numerical simulation has become more and more important in astrophysical researches in the last few decades. In this presentation, we will briefly introduce the simulation we are adopting in our group, as well as one of the currently undergoing simulation projects, aiming to reveal the effect of magnetic field orientation and other effects on star formation rate in filament clouds. The importance of magnetic field orientation in star formation has been gradually realised in the recent decades. However, the effect of different orientations on star formation rate in particular types of filaments is still yet to be understood, which will be the central topic of the project.　
　
時間：2017.05.20(六) 15:45 ~ 16:00
地點：香港中文大學 科學館LT4
講者：GUO Zitan
語言：英語

#131

此活動由香港中文大學物理系主辦。

物理系學生會議：具有限化學勢的大質量中微子於宇宙擴張史及大尺度結構的影響

Talk:- Influence of Massive Neutrinos with a Finite Chemical Potential on the Cosmic Expansion History and Large Scale Structure

Due to their high abundance, massive cosmic neutrinos would have a significant influence on cosmology, especially in terms of large scale structure. Ever since the discovery of neutrino oscillation, which confirmed that neutrinos have finite masses, many efforts have been made to constrain neutrino masses from cosmology. However, none of them has considered the possibility of a finite chemical potential, if the neutrinos are not majorana fermions. The work would be the first one to analyse the combined effect of masses and chemical potentials of neutrinos on matter power spectrum of large scale structure, through two physical processes, their influence on the cosmic expansion history, and the neutrino free-streaming. The result would serve as a correction to the constraints of neutrino masses from large scale structure.　
　
時間：2017.05.20(六) 16:15
地點：香港中文大學 科學館LT4
講者：
　　●Zhichao Zeng
　　●Shek Yeung
　　●Ming Chung Chu
語言：英語

#131

此活動由香港中文大學物理系主辦。

物理系學生會議：教科書編成《NSS Physics Insight – A Short Introduction to Special Relativity》

Talk:- NSS Physics Insight – A Short Introduction to Special Relativity

We have developed a textbook (NSS Physics Insight – A short introduction to Special Relativity) teaching Secondary Senior Form students Special Relativity. There are 6 major chapters about Special Relativity included, together with 4 supplementary chapters providing required mathematics skills, like limits and differentiation, integration, vectors and matrices, for students to tackle Special Relativity problems. Time dilation, length contraction, Lorentz transformation and the application of Spacetime diagrams are included in the textbook. We adopted the example-based approach in the textbook, that is, we provided examples for students to follow and some follow-up challenges for them to apply what they have learnt. To arouse interest of the readers, we also made use of comics and dialogues to exemplify the physics concepts and theories. Problem sets are available at the end of each chapter, in which students can test their understanding. It is notable that most of the problems in the textbook were originally designed, with extra features like problems are implemented based on novels, increasing difficulty of problems of similar situations. A full solution manual is also available for students to check their answers and steps. Supplementary notes and explanation are also provided in the manual.　
　
時間：2017.05.20(六) 16:00 ~ 16:15
地點：香港中文大學 科學館LT4
講者：Li Ka Yue Alvin 及 Pang Yiu Yung
語言：英語

#131

此活動由香港中文大學物理系主辦。