A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Research
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

The "o" band for Pan-STARRS and how to get it



 
 
Thread Tools Display Modes
  #1  
Old March 29th 21, 12:00 AM posted to sci.astro.research
Eric Flesch
external usenet poster
 
Posts: 321
Default The "o" band for Pan-STARRS and how to get it

Those who use Pan-STARRS data might bemoan the lack of a "u" band.
There is a quick fix, of sorts -- the POSSI-O band which is centered
on 4050A. While not exactly u, it is blueward of Pan-STARRS grizy,
and overlaps the g band only about 33%. The POSS-I survey was done in
the 1950's and it covers all sky down to declination -33, which means
it overlaps the entire Pan-STARRS sky which is down to declination
-30. POSSI-O can be calibrated to Pan-STARRS via the POSSI-E band
which is just Cousins R.

Lupton 2005 gives the following transform for SDSS r & i to Cousins R:


R = r - 0.2936(r-i) - 0.1439

and this works here because Pan-STARRS r & i are just the same as
SDSS. So get the R-E offset and add it to O, and boom, you've got
Pan-STARRS "o" to add to their "grizy" bands -- "ogrizy" now. This is
for the brighter objects, as POSS-I is about 2 magnitudes less deep
than Pan-STARRS.

There is one issue remaining, though, and that is that the POSSI-O and
POSSI-E bands must be correctly calibrated to each other.
Unfortunately, the USNO-B has bad offsets there, and USNO was the only
place which digitized the Galactic POSS-I plates. There is a history
there, USNO-A1.0 was USNO's first release which digitized the entire
POSS-I survey and it was well-calibrated. But shortly thereafter they
released USNO-A2.0 for the purpose of better astrometry, but some
nasty photometric offsets got introduced also, and the POSS-I coverage
was only down to declination -12 (replaced by UKST southwards of
there). These bad photometric offsets were passed onwards to the
USNO-B catalog, unfortunately.

A while ago I released the ASP catalog (2017,PASA,34,25) which
presents the whole POSS-I data (375M sources) calibrated correctly to
the USNO-A standard and also to the APM (which covered POSS-I away
from the Galaxy) standard. The calibrations are shown on the web
pages:

http://quasars.org/APM-USNOB-plate-calibration.txt for USNO-B, and
http://quasars.org/APM-USNOA-plate-calibration.txt for USNO-A1.0

So the ASP catalog gives the full POSS-I data with POSSI-O calibrated
correctly (or at least better than anywhere else) to POSSI-E. So that
data can be mined for "Pan-STARRS o", using the above technique.

Eric Flesch
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
just THREE YEARS AFTER my "CREWLESS Space Shuttle" article, theNSF """experts""" discover the idea of an unmanned Shuttle to fill the2010-2016 cargo-to-ISS (six+ years) GAP gaetanomarano Policy 3 September 15th 08 04:47 PM
and now, Ladies and Gentlemen, the NSF "slow motion experts" have(finally) "invented" MY "Multipurpose Orbital Rescue Vehicle"... just 20 gaetanomarano Policy 9 August 30th 08 12:05 AM
"AudiO COmic Madness" "Catherine's Rage" ( Former Band Teacher Sentenced To 20 Years - Robert Sperlik (IL)) Bozo Misc 0 September 11th 06 01:20 AM


All times are GMT +1. The time now is 11:31 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.