CaII K-Line Index

We calculate CaII K-line indices from our images every day and show the result below. The index shown is using only bright activity features.

To get more information about the BBSO K-line data, click here. Since late 1995 our K-line filtergrams are taken with a Kodak Megaplus 1.4i digital CCD camera. They are shown in full size at our latest image page. For earlier images and the index itself, look in our FTP archive.

We present below daily indices of excess K-line brightness and area. The yellow index is the integrated brightness above 7.5% of the central disk brightness; the green index is the corresponding area. For an index comprising the total excess K-line emission please contact us.

The bandpass of our Daystar filter was changed from 3A to 1.5A at day number 254, 1996. We have adjusted our thresholds for the index to compensate for the new bandpass.

Indices for excess K-line brightness and area are also available for 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005.

© BBSO/NJIT - Last modified: August 30, 2006