Scanning equipment for the solar monochromatic He I 10830 spectrum

Chin. Astron. Astrophys. (1994) 16/Z 233-240 Copyright @ 1994 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0275-1062/94524.00+.00

Pergamon

ABSTRACTS OF OTHER PAPERS SINICA 34/4 (1993) AND ACTA Scanning

equipment

41,

CHUAN-JIN,

WANG

FROM ACTA ASTRONOMICA ASTROPHYSICA 14/l (1994)

for the solar monochromatic He I 10830 spectrum You JIANLu JING, FAN ZHONG-YU Purple Mountain Observatory, Nanjing

210008

This paper describes an equipment for infrared image scanning, attached to the solar spectrograph of Purple Mountain Observatory. Using mosaic method enables us to obtain the monochromatic He I 10830 image. The central frequency, spatial and spectral resolution are all adjustable. Real time He1 10830 line spectrum and continuum over a certain bandwidth are recorded. Various problems in the monochromatic image obtained are discussed. (AAnS, 1993, 34, 374-379). Homogenization of the Chinese Joint Universal Time in 1962-1988 LIAO DECHUN, JIN WEN-JING, Xv TONG-QI, Lu PEI-ZHEN Shanghai Observatory, Shanghai 200030 This paper discusses and gives the corrections required for homogenizing the Chinese Joint Universal Time for the period 1962-1988. The main effect of the change in the aberration constant is a constant term of about 1.7ms; that of the systematic FK5-FK4 catalogue difference is a constant term of about -0.7 ms and an annual term of mean amplitude 1.7 ms; the annual amplitude caused by the change in the nutation model is between 0.5 and 1.5 ms, constrained by the long-period terms of nutation. A comparison shows that, because of the FK5-FK4 systematic difference, the mean yearly discrepancy between the Chinese Joint Universal Time and the B87C02 Series of BIH is slightly increased after the homogenization than before; but the rms fluctuations in most years are reduced. ( AAnS 1993, 34, 397-404). A new method & MAO

WEI

for determining

Yunnan

Observatory,

the tilt of atmospheric Iiunming

isopycnic

layers

FAN YU

650011

According to the principles of absolute determination of instantaneous refraction using the Lower Latitude Meridian Circle now being designed in Kunming, a new method is proposed to determine the tilt of atmospheric isopycnic layers using observations made alternately at the prime vertical and the meridian. Formulae are derived and accuracy is estimated. (AA& 1993, 34, 405-410). The problem of calculating the perturbations in orbital determination of artificial satellites over a long arc LIU LIN & LIAO XIN-HAO department of Astronomy, Nanjing University, Nanjing 210008 It has been customary to use Encke’s method of special perturbation (more precisely, Encke’s transformation in coordinate perturbation) when calculating the orbit of artificial satellites over a long arc. We show that the key lies in the selection of the reference orbit and the numerical method, and does not depend on the use of Encke’s transformation. Stabilization is a more important issue in this problem. (AAnS 1993, 34, 411-422). Problem Observatory,

of two bodies Nanjing

with a generalized

210008;

SUN YI-SUI

potential

Nanjing

FU YAN-NING Purple

University

Mountain