[vsnet-chat 3941] R: Delta Sco observed by SOHO

["Toni Scarmato" <toniscarmato@hotmail.com>]

Dear Farrel, dear all,  I have read this chat and because I am watching
every day the SOHO image for to find comets, this is my comment:

I Have valued that the magnitude limit of LASCO C3 is 9 in the better
images.
Unfortunately, the quality of the images is not always optimal.
Moreover there is too noise that can change the magniutde of the objects.


Regards,

Toni Scarmato

----- Original Message -----
From: Fraser Farrell <fraser@trilobytes.com.au>
To: <vsnet-chat@kusastro.kyoto-u.ac.jp>
Sent: Wednesday, January 03, 2001 1:20 PM
Subject: [vsnet-chat 3939] Delta Sco observed by SOHO


The SOHO spacecraft can be used to observe more than just the Sun and
suicidal comets. Hundreds of stars pass through its view each year;
including Delta Sco, which can be seen in the LASCO C3's field of view
during the last week of November.

I've taken a quick look at SOHO archival images from 1998 and 1999, and
Delta Sco is discernably brighter in the 1999 images. Unfortunately I
can't provide numbers because their archive server is refusing to let me
do FITS downloads which I could feed to image analysis. I was restricted
to viewing the GIF equivalents and visually comparing the images of Delta
Sco with nearby stars :(

Nevertheless, it is clear that Delta Sco was still brighter than "normal"
during November 1999. So it probably didn't return to quiescence at any
time during solar conjunction, and we're now entering the 6th month of
this current outburst.

I don't know the limiting magnitude of LASCO C3 - or how its images
compare to visual observation - but it seems to be useful for filling in
the annual data hole for variables near the ecliptic.



cheers,
Fraser Farrell

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp