[vsnet-chat 1688] Akimasa Nakamura's images (1997 May 5 - 1998 Apr. 15)

[Seiichi Yoshida <seiichi@muraoka.info.waseda.ac.jp>]

MISAO Project Examination Report (Mar. 12, 1999)

Hello. I am Seiichi Yoshida working on the MISAO project.

Akimasa Nakamura contributed 308 images of comets and asteroids taken
with 0.60-m reflector to the MISAO Project. Thank you so much. Here I
introduce you the examination result.

12 images of the 308 ones were failed to be examined by the PIXY
system. Matching has filed in some cases, only few stars were detected 
in other cases. In addition, every star was double-detected in case of 
another three images, because of tracking the target object. The rest, 
293 images, were properly examined.

The field of view was 15.52 x 10.35 arcmin for 11 images, 13.11 x 8.74 
arcmin for the other 282 images. All images were examined using the
USNO-A1.0 because of the narrow field. The limiting magnitude was
about 16.5-19.2 mag, the faintest magnitude was about 18.0-20.5 mag.
They are what the PIXY system output, so some of the images actually
contain much fainter stars. About 25-500 stars were detected from one
image. 

In matching of the PIXY system between detected stars and data in star
catalog, the score (the rate of detected stars which were mapped onto 
data in star catalog by the mapping function obtained in matching)
becomes usually greater than 0.5. On the other hand, the score becomes 
less than 0.2 when matching failed. So we can judge if matching
succeeded or failed at the threshold 0.3. However, there are many
images in this time whose score became less than 0.3 even if matching
succeeded, probably because of the narrow field. The threshold was
about 0.13, much less than the case of Ageo Survey images. 

Many stars not recorded in the USNO-A1.0 were detected. Some of them
are the target comets or asteroids of Akimasa. Because of the narrow
field, stars' proper motion is conspicuous. So some stars could not be 
a pair with data in star catalog properly. There may be some new
objects in the rest except for those stars. However, they are all too
faint to be compared with the Ageo Survey images.

Because of the narrow field, only five known variable stars are in the 
image. Here are the magnitude estimation.

GT Hya
1997 May  5.66042	<18.3C

DQ Gem
1998 Apr 15.44687	11.1C
1998 Apr 15.45139	11.0C
1998 Apr 15.45556	11.2C

CF Cnc
1998 Mar 18.51510	<19.0C
1998 Mar 18.54722	<18.8C

V796 Tau
1998 Mar  2.47396	12.6C
1998 Mar  2.47778	12.6C

V875 Tau
1998 Mar  2.47396	18.8C
1998 Mar  2.47778	18.5C

GT Hya is recorded in the GCVS as follows.

GT HYA  R.A.=14 26 48.17  Decl.=-26 16 39.3  13 - 14 mag (P)  type:RR:

It implies the magnitude range is 13-14 mag. However, no bright star
is at the point on the image. In addition, no bright data is
recorded in the USNO-A1.0. However, there are another data near by
this position:

USNO0600.09679667   14 26 50.72  -26 16 44.1  13.7 R  14.8 B  (14.11V)

This star was detected as 14.5C mag. GT Hya may be this star.

One suspicious variable star, NSV01346, was in the image field. But it 
was saturated and the magnitude was inaccurate.

NSV01346
1998 Mar  2.47778	8.4C

One of the candidates in the GSC, compiled by Minoru Sato, STM0799,
was in the image field. It is recorded in both the GSC and USNO-A1.0
as 7.7 mag star. It was already confirmed by the Ageo Survey image on
Sept. 12, 1998, not detected and to be fainter than 9.2C mag. But now
the in-existence becomes much more confident by the Akimasa's images.

STM0799
1998 Mar 22.51441	<18.8C
1998 Mar 22.51771	<19.1C

Four more new errors in the USNO-A1.0 (MisE.UA1) were discovered. 

MisE.UA1.00035
USNO0825.08145944  13 49 12.766  -03 33 23.98  15.8R  21.3B
1998 Mar 22.72674	<18.8C
1998 Mar 22.73889	<18.4C
1998 Mar 22.74479	<18.6C

MisE.UA1.00036
USNO1275.07317514  08 20 02.575  +37 34 01.15  13.5R  21.0B
1998 Mar 22.51441	<18.8C
1998 Mar 22.51771	<19.1C

MisE.UA1.00037
USNO1200.06068895  08 20 27.017  +37 27 14.47   7.7R
1998 Mar 22.51441	<18.8C
1998 Mar 22.51771	<19.1C

MisE.UA1.00038
USNO1050.01254273  04 21 39.823  +17 06 20.32   9.6R  19.0B
1998 Mar 22.45521	<18.3C
1998 Mar 22.45938	<18.4C
1998 Mar 22.46319	<18.2C

P.S.
If you would like examination report of your own images, please make a 
contact to Seiichi Yoshida.

The past MISAO project examination reports are available at:
  http://vsnet.info.waseda.ac.jp/muraoka/members/seiichi/misao/

--
Seiichi Yoshida
Muraoka Lab., Waseda University, Japan
seiichi@muraoka.info.waseda.ac.jp
http://vsnet.info.waseda.ac.jp/muraoka/members/seiichi/index.html

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