안녕하십니까.

오는 수요일(3월 25일) 오후 4:00에 아래와 같이 2026년 상반기 정규 콜로키움이 진행될 예정입니다.

발표 후에는 연사와의 대화시간(5:00-5:40) 및 저녁 식사가 예정되어 있으니 많은 참여 부탁드립니다.

발표자: 진선호 박사 (KASI)

호스트: 문홍규

장소: 장영실홀 331-2 및 원격 연결

일시: 3월 25일 (수) 오후 4:00

접속주소: https://us06web.zoom.us/j/84840334355?pwd=3FUkcuaYwNQwscjoUSo3ulk6KPPo6x.1

교육학점: 천문연 소속 현장참석자의 경우 필수 0.5 학점 부여

제목: Development of the SQUIDPOL Polarimeter and Initial Scientific Results

초록: 

Seoul National University Quadruple Imaging Device for Polarimetry (SQUIDPOL) is a low-cost, multi-channel imaging polarimeter. The instrument consists of a rotating half-wave plate, a non-polarizing beamsplitter (NPBS), and four wire-grid filters, enabling linear polarization measurements in a single exposure with B, V, and Cousins R and I bandpass filters. Since July 2024, SQUIDPOL has been mounted on the 60 cm telescope at the Pyeongchang Observatory of Seoul National University and has been used for both research and educational purposes.

In this talk, we outline the development process of SQUIDPOL, including its optical and optomechanical design and on-site performance evaluation. In particular, we found that the dielectric coating inside the NPBS causes different polarization angles for transmitted and reflected light, and we therefore developed a correction scheme. Using this scheme, we achieved a polarization accuracy of 0.15% from bright, strongly polarized standard stars and obtained polarimetric performance comparable to that of other research-grade polarimeters.

Furthermore, we will introduce two research papers on comet polarimetry that utilized SQUIDPOL. One is Lim et al. (2025), which conducted multi-wavelength polarimetric observations of the exceptionally bright comet C/2023 A3 (Tsuchinshan-ATLAS), and the other is Choi et al. (2026), which observed the interstellar comet 3I/ATLAS using the instrument. [1][2] The results from SQUIDPOL were consistent with the linear polarization degrees obtained from other observatories. We will also discuss ongoing and future observational projects using the instrument.

[1] Lim et al. (2025), ApJL, 983, L19.
[2] Choi et al. (2026), ApJL, accepted for publication.

진행언어: 한국어

슬라이드언어: 영어

원격 접속 방법 :

A. 웹 브라우저: Chrome을 추천하며 아래 주소를 실행시 Zoom 구동을 위한 프로그램이 설치될 수 있음

B. 접속 주소: https://us06web.zoom.us/j/84840334355?pwd=3FUkcuaYwNQwscjoUSo3ulk6KPPo6x.1

C. 유의사항: 접속 후 "마이크는 뮤트로 설정" - 기본설정은 뮤트로 되어있음 > 질의 응답시간에는 마이크를 사용해서 질문 가능함

천문연 콜로키움 위원회 (김종수, 선광일, 이창원, 문홍규, 노혜림, 한정열)

운영위원회 (김진호, 홍준석, 석지연, 이재현, 유영삼, 송상헌)

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Dear all,

The KASI's regular colloquium is scheduled at Mar. 25, as shown below.

A conversation session with speakers and dinner are scheduled after the colloquium.

Speaker: Dr. Sunho Jin (KASI)

Host: Hong Kyu Moon

Place: Jang Yeong-sil Hall 331-2 & Online

Time: March 25 (Wed) 4:00 pm 

Access: https://us06web.zoom.us/j/84840334355?pwd=3FUkcuaYwNQwscjoUSo3ulk6KPPo6x.1

KASI Educational credits: 0.5 educational credits are awarded to off-line attendees.

Title: Development of the SQUIDPOL Polarimeter and Initial Scientific Results

Abstract: 

Seoul National University Quadruple Imaging Device for Polarimetry (SQUIDPOL) is a low-cost, multi-channel imaging polarimeter. The instrument consists of a rotating half-wave plate, a non-polarizing beamsplitter (NPBS), and four wire-grid filters, enabling linear polarization measurements in a single exposure with B, V, and Cousins R and I bandpass filters. Since July 2024, SQUIDPOL has been mounted on the 60 cm telescope at the Pyeongchang Observatory of Seoul National University and has been used for both research and educational purposes.

In this talk, we outline the development process of SQUIDPOL, including its optical and optomechanical design and on-site performance evaluation. In particular, we found that the dielectric coating inside the NPBS causes different polarization angles for transmitted and reflected light, and we therefore developed a correction scheme. Using this scheme, we achieved a polarization accuracy of 0.15% from bright, strongly polarized standard stars and obtained polarimetric performance comparable to that of other research-grade polarimeters.

Furthermore, we will introduce two research papers on comet polarimetry that utilized SQUIDPOL. One is Lim et al. (2025), which conducted multi-wavelength polarimetric observations of the exceptionally bright comet C/2023 A3 (Tsuchinshan-ATLAS), and the other is Choi et al. (2026), which observed the interstellar comet 3I/ATLAS using the instrument. [1][2] The results from SQUIDPOL were consistent with the linear polarization degrees obtained from other observatories. We will also discuss ongoing and future observational projects using the instrument.

[1] Lim et al. (2025), ApJL, 983, L19.
[2] Choi et al. (2026), ApJL, accepted for publication.

Language: Korean

Slide Language: English

Remote access procedure:

A. Web browser: Chrome - When executing the address below, a program for additional zoom operation can be installed.

B. Access: Go to https://us06web.zoom.us/j/84840334355?pwd=3FUkcuaYwNQwscjoUSo3ulk6KPPo6x.1

C. Notice: After join, Please mute your microphone. - The default setting is microphone mute. > After the presentation, during the Q&A session, you can use the microphone to ask questions.

KASI Colloquium committee (Jongsoo Kim, Kwang-Il Seon, Chang Won Lee, Hong-Kyu Moon, Hyerim Noh, Jeong-Yeol Han)

Working committee (Jinho Kim, Junseok Hong,  Ji Yeon Seok, Jaehyun Lee, Young Sam Yu, Sanghun Song)