1993 Fiscal Year Final Research Report Summary
Observational Studies on Accurate Optical Positions of Faint Celestial Objects by using Meridian Circle
| Project/Area Number |
03402001
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | National Astronomical Observatory (NAO) |
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Principal Investigator |
YOSHIZAWA Masanori NAO Assistant Professor, 位置天文・天体力学研究系, 助教授 (20126197)
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| Co-Investigator(Kenkyū-buntansha) |
SEKIGUCHI Masaki NAO Assistant, 光学・赤外線天文学研究系, 助手 (40216528)
SOMA Mitsuru NAO Assistant, 位置天文・天体力学研究系, 助手 (30187885)
KUWABARA Tatsuichiro NAO Assistant Professor, 位置天文・天体力学研究系, 助教授 (70153434)
MIYAMOTO Masanori NAO Professor, 位置天文・天体力学研究系, 教授 (30012850)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Meridian Circle / CCD / Optical Astrometry / Digital sky Mapping / Reference Frame / QSO |
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| Research Abstract |
We have developed a CCD micrometer used for meridian observations working under the drift-scanning CCD driving mode. A group of faint celestial objects like QSOs have been selected and observed for their precise optical positions with the CCD meridian circle.
The developed CCD micrometer was found to be able to observe faint stellar objects of 15.7 V-magnitude when attached to Gautier meridian circle at National Astronomical Observatory, Mitaka. A new image analysis software system was also developed with the help of a new filter method to determine precise location of observed stellar images. The analysis system has been used to select a few hundreds of celestial objects found within an area of 30 arcminute square (corresponding to the field of view of the CCD) and to determine the positions of the selected images with the internal accuracy better than 0.1 arcsecond.
The optical position of 3C273 was observed based on FK5 system by using the CCD meridian circle. The observed Right Ascension of 3C273 was found to be in good agreement with its VLBI position. On the other hand, the position of Pluto was observed to find that the ephemeris Right Ascension of Pluto given in DE211 of JPL might be systematically shifted by 0.1 to 0.2 arcsecond. The above mentioned results were reported at the three international conferences (1991,1992 and 1993).
We have been observing a digital sky mapping program since December of 1992 and optical positions of about twenty QSOs (and faint reference stars around the target QSOs) since December of 1993. The observations of the faint reference stars (about 150 stars in total of 9 to 11 magnitude) around the QSOs are also included in the regular Tokyo Photoelectric Meridian Circle program at Mitaka. The results of those continuing works will be published after the end of individual programs.
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