MISAO Project

Japanese version       Home Page       Updated on October 7, 1998

1998 Sept.10

    MISAO Project new home page    

Hello. I am Seiichi Yoshida, working on the MISAO Project.

Now that I have updated the home page of the project, please let me introduce you the overview and the current situation of the project.

The MISAO stands for

Multitudinous Image-based Sky-survey and Accumulative Observations

The main works to do are:

  • Making an automatic star detection and identification software.
  • Examining images and finding new objects or new variable stars, catalog errors, etc.
  • Putting the images, photometric results of all known variable stars, and a list of candidates of new remarkable stars in the public at the home page.

All about the project is at:


and what the project can show you after examining your image is available at:

http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet/msg01591.html http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet/msg01592.html http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet/msg01593.html http://www.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet/msg01594.html

these are my mails posted to VSNET.

Now I am also working on the Bistar Survey with KenIchi Kadota. This is a wide field survey with CCD operated at Hanadateyama Observatory called "Bistar" in Ibaraki, Japan.

One of the purposes of the survey is to prove the ability of the softwares created and distributed freely in the project by discovering new stars actually using those softwares.

The PIXY system is a main software of the project, which stands for:

Practical Image eXamination and Inner-objects Identification system

It detects stars in the image and identifies them with data in GSC or USNO A1.0 catalog automatically. It is available freely at the MISAO Project home page. I have been improving it by examining CCD images taken under the Bistar Survey. The system became something practical until late July. Actually, the data in the MISAO Project home page are all obtained by the PIXY system.

The PIXY system is implemented fully in Java. So it works also on Windows, although it was only for UNIX system before.

CD-ROMs of a star catalog, GSC or USNO A1.0, are required to run the system. After detecting all stars from the image, the system collates them with data in those catalogs and lists up candidates of new objects, which are not recorded in the catalog, candidates of variable stars, whose brightness in the image is very different from that recorded in the catalog, and candidates of catalog errors, which is recorded in the catalog but not found in the image.

I introduce you the results of CCD images taken with 35mm lens, some of them are open in the public at the home page. The field of view is about 22x15 deg. About 3500 stars are found limiting at about 9 mag. Although the system can find about 10 thousands or almost 20 thousands stars until 11-13 mag in the images, it is hard to process so many data and now the system restricts at about 9 mag. Among about 3500 stars, 5-10 candidates of new stars, several candidates of catalog errors and about 30 candidates of variable stars are found by the PIXY system. The examination takes about 15 minutes for an image. If examining an image taken with a large telescope, whose field of view should be very small and which does not contain so many stars, the examination takes about 5 minutes. But a wide field image contains stars about 10 times, so it takes much time.

But most of these remarkable stars are known variable stars. In order to discover new objects, identification with known variable stars is also required after collating with GSC or USNO A1.0 by the PIXY system.

After mid July, I have been creating a software to identify all data output by the PIXY system with known variable stars. Now identification with data recorded in GCVS, IRAS PSC, NGC2000, etc., is done almost automatically.

As a result, most of remarkable objects, mentioned above, several dozens an image, are identified with known variable stars. However, 5-10 remarkables stars are not identified with known objects. Most of them are recorded in GSC, so they are not new objects. But the brightness is very different, so they may new variable stars. Anyway further observations are required to confirm. I register those objects as MISAO objects. The list of MISAO objects are also available at the home page. Some of them may be really unknown important stars. If someone makes it clear, the honor of the discovery will be the observer's or the researcher's.

Unfortunately the automatic identification system is not open, because I have not yet been permitted to distribute or put open in the public the reference catalogs, GCVS, IRAS PSC, etc. When distribution is permitted, I can make a CD-ROM containing the PIXY sytem, identification system and those catalogs, then everyone can start survey at home. Without distributing, if it is permitted to put them open in the public, I will make a identification system which can be run in a WWW browser. In that case, you will access to the MISAO Project home page, input the position of a remarkable object to the system and confirm that it is a known object or not.

However, I can already show you the result of identification, because the catalogs referenced by the system are open. Therefore, if you would like to identify some objects right now, please send me an E-mail and I will reply the identification result to you.

Although known variable stars are nuisances for new objects discovery, the photometric data of them are important. The MISAO project also accumulates the photometric data of all known variable stars in the image, not only finding and numbering unknown remarkable objects. For example, an image of 35mm lens taken under the Bistar Survey contains about 500 known variable stars. The total stars until 9 mag are 3500, so one star among 7 stars is variable, although the ratio will change when the system measures all more than 10 thousands stars.

All the results of the Bistar Survey will be open in the public at the home page. In each page, you can mark up every detected variable star in the image, and you can see the measured data or recorded data in catalogs of the star. It is so interesting, please see and try it.

If you would like not only to confirm whether new objects exist in your image but also to make the most of photometric data of known stars in your image, please send me your image and I will measure it, put the data open in the public at the MISAO Project home page, and report photometric data to the proper organization. I will also reply the data to you. When the usage of the PIXY system is not clear for you, please send me your image and I will check it. However, I already have many images before examination, so I cannot work on your image very soon.

In my experience, there are so many errors in star catalogs such as GSC, USNO A1.0, etc., and the PIXY system finds so many candidates of new objects. Many of the MISAO objects listed up in the home page will be normal stars which are just not recorded in the catalog. Therefore, when you find some candidates of new objects using the PIXY system, you have to confirm by referring to DSS, etc. Another image taken after several days will also help it.

Seiichi Yoshida
Muraoka Lab., Waseda University, Japan

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