MISAO Project

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September 23, 2000

    PIXY System 2 tutorial pages    

MISAO Project Announce Mail (September 23, 2000)

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

We the MISAO Project have discovered about 1000 new variable stars and reported about 50 thousands magnitude observations of variable stars, based on the about a dozen images offered from many people.

In order to deal with enormous data in the MISAO Project activity, we use our original software, the PIXY (Practical Image eXamination and Inner-objects Identification) System.

Now the next version of the system, PIXY System 2, is being developed, based on the experience of the MISAO Project activity. The old version could examine each image automatically. But some other scripts were required to search the database for magnitude report or new variable stars discovery. The PIXY System 2 is planned to integrate all of the current tasks of the MISAO Project. So the system will be an integrated environment for a survey project.

The latest version of the PIXY System 2 is 2000 September 16. The following two main functions are implemented in that version.

  • Examine one image, compare with star catalog, and measure position and magnitude of all stars.
  • Compare two images and search new objects.

In the MISAO Project Home Page, the tutorial pages which introduce the usage of the PIXY System 2 and the applicative examples with sample images are available. The contents are as follows.

  • Examine your image
  • How to discover comet or asteroid
  • How to discover variable star

  • Accurate astrometry of Nova Aql 1999
PIXY System 2 Home Page:

Those pages have sample images, so you can download them and try the system operations by yourself.

The "Examine your image" page introduces how to examine your image, that is, to obtain the coordinates of the image center, the field of view, etc., to list up candidates of new stars, to measure the coordinates and magnitude of all stars, and so on. There is an asteroid in the sample image. After examination using the USNO-A2.0 catalog, the asteroid is marked up as a red circle.

Here are the steps to examine your image using the PIXY System 2. A dialog appears to select a star catalog and input R.A. and Decl. on the way. But you have to do nothing else.

  1. Push Image Examination button.
  2. Select [Operations] - [Open Image] menu and open the image.
  3. Select [Operations] - [Detect Stars] menu.
  4. Wait for some seconds.
  5. Select [Operations] - [Matching] menu.
  6. Select a star catalog and input approximate R.A. and Decl. and some more.
  7. Wait for some seconds.
  8. Select [Operations] - [Make Pairs] menu.
  9. Wait for some seconds.

The "How to discover comet or asteroid" and "How to discover variable star" pages introduce how to compare two images and discover new objects. There are an asteroid and some variable stars in the sample images. After examination those objects will be found by yourself. Especially, the sample images of the "How to discover variable star" page is the one actually three MISAO new variable stars were discovered from.

Here are the steps to search a new variable star using the PIXY System 2. No parameter setting is required so you have to do nothing. In these cases, no star catalogs such as GSC or USNO-A2.0 are needed.

  1. Push Multiple Examination button.
  2. Select [Operations] - [Open Image] menu and open the first image.
  3. Select [Operations] - [Open Image] menu and open the second image.
  4. Select [Operations] - [Matching] menu.
  5. Wait for some seconds.
  6. Select [Operations] - [Create R-GB Image] menu and an R-GB image appears.
  7. Search a colorful star in the R-GB image.

The R-GB method is a way to search variable or moving stars designed by KenIchi Kadota. Two images are composed, one represents red color and the other represents blue and green color, and a color image is created. Whole of the new image becomes monochrome, however only variable or moving stars become red or greeny blue.

The "Accurate astrometry of Nova Aql 1999" page introduces the example that the PIXY System 2 can measure the position of a star automatically in one arcsec or higher accuracy even on an image taken using a small telescope.

The PIXY System 2 is being released about once in a month. Your advice and proposals are welcome, which reflect on the development schedule. Please download the software and try to use it.

* The sample images are taken by KenIchi Kadota and Yasukazu Ikari.

The past MISAO project announce mails are available at:


Seiichi Yoshida

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