comparison of obsevational conditions at maidanak and nyukasa

Comparison of Obsevational Conditions

at Maidanak and Nyukasa

Toshifumi Yanagisawa （柳沢俊史）Hirohisa Kurosaki （黒崎裕久）

JAXA, Japan

presented by Takashi Ito ( 伊藤孝士 ), NAOJ

SummarySummary

Seeing (instrumental) at Maidanak

Seeing (instrumental) at Nyukasa,Japan

~ (almost the same)

AuthorsAuthors

YanagisawaYanagisawa

Kurosaki

2009 Novemberat Maidanak

AbstractAbstract

In order to check the observational condition

at Maidanak, we measured and compared the instrumental seeing and the sky background at Maidanak and Nyukasa, Japan, using the same instrument.

Our results are as follows:1. Seeings at Maidanak and at Nyukasa

turned out almost the same.2. The sky background at Maidank is about

half compared with that at Nyukasa.

Observation at MaidanakObservation at Maidanak

Date: 2009 November 17Telescope: Celestron C8 　　　　　　 (D:200mm, F2032mm)Camera: N.I.L. 1K1KEquatorial mount: Vixen GPDExposure time: 10sec

Celestron C8

Vixen GPD

N.I.L. 1K1K

Observation at NyukasaObservation at Nyukasa

Date: 2010 May 17Telescope1: Celestron C8 　　　　 (D:200mm, F2032mm)Camera1: N.I.L. 1K1KEquatorial mount: Showa 25ELExposure time: 10sec

(for reference)Telescope2: Takahashi BRC250 　　　　　　 (D: 250mm, F1268mm)Camera2: N.I.L. 4K2.7KEquatorial mount: Showa 25ELExposure time: 10sec

Celestron C8

N.I.L. 1K1K

N.I.L. 4K2.7K

Takahashi BRC250

Showa 25EL

Nyukasa-yama observatory, JAXA, JapanNyukasa-yama observatory, JAXA, Japan

Routine observationsby JAXA about ... space debris near-Earth objects main belt asteroids others

"入笠山 "a mountain where you

always need an umbrellabecause of frequent rain

Nyukasa-yama

Comparison of instrumental seeingComparison of instrumental seeing

Instruments Maidanak Nyukasa

Celestron C8 3.30″ 3.38″

Takahashi BRC250

(1.96″) 2.01″

Sky background 100 ADU 210 ADU

Pick up seven objects near the center of frames Measure their FWHM through IRAF Record the central (fourth) values Average the values over the frames of the day

DiscussionDiscussion

Seeing at Maidanak is not supposed to be better than Nyukasa ?

Telescope conditions were slightly different At Nyukasa, the telescope was set in a dome At Maidanak, the telescope was set out of the dome Their Equatorial mounts were different (see the photos)

... We will set up exactly the same condition at Nyukasa, and again measure the seeing soon