I wrote the following in real-time while playing with a newly built
"test"
database. It contains <1% of the TASS MkIII data. My intent was just
to
see if the software worked and as a practical test to see if the tools
would
support random ad-hoc analysis. In the process I may have found
something
of interest. I post my notes to show (1) the thing I found and (2) to
show
by example what kind of "make it up as you go" analysis can be done.
I've
said it before - you can do this kind of stuff remotely from the comfort
of
your own PC. give it a try.
++++++++++++++++++++++++++++++++
I have just created my first merged database using a "seeded" catalog.
I think it works now. (Stalling for time as the software loads)
Postgres encourages experimental programming.
Sometimes a+b is faster to compute than b+a and you can never tell
which is the best order until you try both. This weekend, runs were
taking 10 or 12 hours then crashing. This morning I was able to merge
600K observations with a 2.5M entry catalog while getting ready for
work.
I am using a P200 with 96 MB RAM and IDE Disks
I made up a feature list for what I call "version 1.0". This software
works
well enough now that I'll post it as version 0.7. 1.0 will contain what
I consider a the minimal required feature set for a TASS database
The big part missing is photometric calibration (done. lets look at
some
data)
Number of observations I: 270723
r: 376031
v: 0
total : 646754
Catalog entries:2695888
Entries in "seed" catalog:2522831
Delta: 173057
Apparently, of the 646754 observations processed only 173057 were not
matches
to Arne's TASSM16 catalog list. 646754 observations is only a drop in
the
bucket of available data. It is only one night's worth. I picked a
night
that was good for Glenn, Nick and Tom. and processed 300+ frames of
data.
As there are so many non-matches one question to ask is "Are there any
stars seen multiple times by at least two sites that are _not_ in Arne's
"complete to mag 16" catalog.
First question to the database: What is the maximum observation count
of any star? Answer "6". So now we know at least one star was seen by
six TASS cameras on one night. Next question: How many where seen six
times? Answer "1359". That's not to many to print. I'll just browse
the list of 1359.
The tass catalog now uses a convention when assigning IDs to objects.
objects from the TASSM16 catalog are given IDs in the range 1 to about
2,500,000. Catalog entries added after the seeding process begin with
10,000,000. It turns out there are 13 of these entries.
In simple terms. These are 13 objects in the catalog, each seen by six
TASS cameras all on the same night and not in Arne's catalog. Here is
the
list:
testdb=> select tass_id, ra::float/3600000.0 as ra,
dec::float/3600000.0 as dec
from tass_cat
where obs_count=6 and tass_id > 10000000;
tass_id| ra| dec
--------+----------------+------------------
10003825|2.80183333333333| 1.26503333333333
10006686| 4.9697| 1.14985
10006736|5.00426666666667| 0.99155
10006856|5.09001666666667| 1.20248333333333
10006898| 5.12235| 1.00616666666667
10153905|346.615083333333|-0.492915833333333
10154628|347.089083333333|-0.657548888888889
10155146|347.446916666667|-0.826282222222222
10162983| 352.7346|-0.502115833333333
10171104|358.629316666667| 0.39355
10171200|358.685933333333|-0.799748888888889
10171277| 358.72925| 0.998466666666667
10171878|359.112533333333|-0.587399166666667
(13 rows)
Now let's look at the raw data for one of these.
testdb=> select * from observ_3i01 where tass_id = 10006686
testdb-> union
testdb-> select * from observ_3v01 where tass_id = 10006686
testdb-> order by julian_date;
tass_id|sourceid|julian_date| ra|
dec|mag_inst|mag_erro|ccd_no|site_id
--------+--------+-----------+--------+-------+--------+--------+------+-------
10006686| 154| 696720180|17887680|4143240| 11032| 54|
2|G
10006686| 137| 696761119|17889120|4138560| 11740| 64|
1|G
10006686| 238| 696795010|17890920|4139640| 11297| 33|
1|H
10006686| 199| 696797350|17892360|4136400| 11667| 49|
0|H
10006686| 276| 696798680|17893800|4137480| 10930| 35|
2|H
10006686| 128| 696804620|17891640|4141440| 11125| 85|
0|G
(6 rows)
Interesting, a mag 11 "star". Wow. Look at the Ra column. It goes up
with JD. Maybe an Asteroid? I'll leave further analysis to the experts
But my guess is that Ra increasing monotonicaly with JD is not caused by
random chance not with six cameras at two sites.
If anyone wants some data tables let me know what you
want and I'll e-mail or post the data. If it turns out we have detected
13
"slow mover" asteriods in one night picked at random I am inpressed.
--
--Chris Albertson home: chrisja@jps.net
Redondo Beach, California work: chris@topdog.logicon.com