Skip to main content

Announcing the BSM epoch photometry database v. 2.0

3 posts / 0 new
Last post
HQA's picture
Announcing the BSM epoch photometry database v. 2.0

As part of the AAVSOnet pipeline processing, we extract every star in every image, and place results in internal files at HQ.  During the course of 2014, we will be releasing epoch photometry databases (EPDs) for each AAVSOnet telescope, containing those nightly extractions.  Some are very straightforward, such as for the Bright Star Monitor, where nearly all images are taken as part of a survey of bright variables.  Some are more complex, where there is a mix of headquarters targets as well as proprietary research from our members.  In this latter case, there will be a release date applied to the proprietary images to give exclusive use to the requestor for a limited time interval, then that photometry will also be released to the membership.

The epoch photometry databases are NOT as good as you could achieve on your own, analyzing individual images.  We use everything coming through the pipeline, whether cloudy or clear, trailed or tracked, focussed or not.  We zeropoiont each image based on calibrated stars within the image, but not necessarily the comparison star sequence for the variable that might have been targeted.  Only transformed data is accepted for the database, so those fields where only a single filter was used will be missing.  That said, everything that does make it into the database is transformed and has the HJD correction applied; and nearly every star on every frame is present, not just the target and a handful of comparison stars.

These databases are for you to data-mine.  Read the individual web pages to see the limitations of each, the access methods, and the many volunteers and staff that were involved to make the imaging possible.

We released BSM EPD v1.0 a while ago; this posting is to announce v2.0.  This includes data from both the original Bright Star Monitor, as well as BSM_South, run by the team of Peter Nelson, Chris Stockdale, and Rod Stubbings.  It contains about half of the data actually taken, with the missing photometry due to fields where calibration is not yet available from the BSM systems themselves, or where time series in a single filter was performed.  You can read about this database and its access at:

We'll continue to extend the BSM EPD as well as those from other telescopes throughout the year.  Enjoy!


wel's picture
Target list?

Hi Arne,

Would you be able to supply a list of the bright star primary targets which the BSMs were observing during the period of time represented in the epoch photometry database?


HQA's picture
bright star primary targets

Hi Doug,

The list of primary targets is linked from the page I gave in the first email.  In many cases, this will help you, but not all.  For example, U_MEN will have a hundred measures, while another target might only have one or two; still others will be identified by a shortened version of a common name; and of course, the target of interest may just be in the field of a primary target.  There are something over 2000 fields in the EPD, covering perhaps 6000 square degrees of the sky.


Log in to post comments
AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484