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MISAO Project Announce Mail (October 13, 2003)
Hello. I am Seiichi Yoshida working on the MISAO project.
Now we are in the generation of automated survey. Many latest images
photographed automatically come to be available immediately via
Internet these days.
The MISAO Project are investigating those public images available via
Internet using the PIXY System 2, and searching new stars.
Now we are checking the following three web sites.
Tomoyuki Itou's library
http://vsnet.kcv.ne.jp/~totomo/tosyokan/
All Sky Automated Survey (ASAS-3)
http://archive.princeton.edu/~asas/
SOHO LASCO C3 images
http://sohowww.nascom.nasa.gov/data/realtime-images.html
These sites have different rules and styles on schedule of
photographing, method to access to the images, and so on.
The PIXY System 2 has a framework of agent.
Therefore, we created an agent for each site, in which the concrete
file names, concrete method to download the images, etc., are
implemented.
The PIXY System 2 can load those agents as plug-in. As as result,
just pushing one button, the system automatically downloads the
images, compares to the Guide Star Catalog (GSC) or Tycho Catalogue,
finds candidates of new stars, and creates an HTML gallery.
Here is an example of the HTML gallery created by the PIXY System 2.
http://vsnet.aerith.net/misao/offer/public-image/gallery/index.html
In the HTML gallery, the candidates of new stars are displayed with
the past images previously registered to the database, or the
Digitized Sky Survey (DSS) images. So it is easy to check whether
those candidates are real or not at a glance.
Here introduces the examples of candidates of new stars detected by
the PIXY System 2 in fact from the public images available at the
three web sites mentioned above.
Please visit the page:
Examination of Public Images of Automated Surveys
http://vsnet.aerith.net/misao/offer/public-image.html
in order to see the images.
1. Tomoyuki Itou's library
Tomoyuki Itou's library provides images of every night, photographing
the sky at south automatically all night. One image covers 15x15
degree area, and contains 8.5 mag stars in good condition.
The image available at Tomoyuki Itou's library is photographed in a
special style using a linear CCD chip. Because the image is mapped in
Mercator projection, the PIXY System 2 cannot compare it to the Tycho
Catalogue as is.
We also find some lattice pattern on the image.
Therefore, the agent of Tomoyuki Itou's library operates some image
processing, to convert the mapping and remove the lattice pattern.
In the case of Tomoyuki Itou's library, it creates an HTML gallery
which shows two images on the same night, and one image of the past
previously registered to the database. It only shows stars detected at
the same position from two images in order to suppress false alarms.
The "Examination of Public Images of Automated Surveys" page
introduces an example of candidates detected from Tomoyuki Itou's
library images.
A bright star, not visible on 2003 July 25, was detected from the
images on Oct. 4. Actually, it is Uranus.
2. All Sky Automated Survey (ASAS-3)
The ASAS-3 is famous for the pre-discovery observations of Nova Sgr
2003 from the early brightening phase in 2003 April. It repeatedly
surveys southern sky up to Decl. +30 degree, once per several days.
The images become available via Internet immediately. The images
contain down to about 14 mag stars.
In order to view the ASAS-3 images at the web site of the All Sky
Automated Survey, we need to follow some steps as follows.
1. View a star chart.
2. Click one star.
3. Select one data and show the light curve.
4. Click a dot in the light curve.
The MISAO Project created an agent which operates those steps
automatically. Then, just pushing one button, the system automatically
downloads the images, compares to the Guide Star Catalog (GSC), finds
candidates of new stars, and creates an HTML gallery.
In the case of the ASAS-3, it creates an HTML gallery which shows the
ASAS-3 images with the Digitized Sky Survey (DSS) images.
The "Examination of Public Images of Automated Surveys" page
introduces an example of candidates detected from the ASAS-3 images.
There is a bright star in the ASAS-3 image, which cannot be found in
the Digitized Sky Survey (DSS) image. Actually, it is a comet
29P/Schwassmann-Wachmann 1, which became bright in outburst in late
September, 2003.
As this example implies, the latest activity of comets can be
monitored in the ASAS-3 images. So I created the following web page.
Recent Images of Comets in ASAS-3
http://vsnet.aerith.net/comet/asas3/asas3.html
3. SOHO LASCO C3 images
The SOHO web site provides the images around the Sun photographed by a
spacecraft, per several dozens of minutes every day. One image covers
15x15 degree area, and contains down to about 9 mag stars.
Because the SOHO LASCO C3 images have many noises, it is too hard to
select real new stars among noises. The noises also disturb the PIXY
System 2 to solve matching between the image and Tycho Catalogue data.
Therefore, the agent of the SOHO LASCO C3 images overlaps three images
photographed at almost same time, and creates an median image. Then it
searches new stars from the median image.
In the case of SOHO LASCO C3 images, it creates an HTML gallery which
shows the SOHO LASCO C3 images with the Digitized Sky Survey (DSS)
images. It also checks the image of the previous day, and only shows
stars detected at the same position from two images (on that day and
the previous day) in order to suppress false alarms.
The "Examination of Public Images of Automated Surveys" page
introduces an example of candidates detected from the SOHO LASCO C3
images.
A bright star was detected from the SOHO LASCO C3 images on two days,
which is not recorded in the Tycho Catalogue. Looking at the Digitized
Sky Survey (DSS) image, it is M104 (Sombrero Nebula).
P.S.
The past MISAO project announce mails are available at:
http://vsnet.aerith.net/misao/
--
Seiichi Yoshida
comet@aerith.net
http://vsnet.aerith.net/
Return to the Powerful Daisaku
vsnet-adm@kusastro.kyoto-u.ac.jp
