Walter's LogBook: September 2004

	Walter's LogBook
	September 2004

Overview

Big progress was made in automation this month on two fronts. One, I fixed the backlash in my dec axis by re-balancing the scope and pushing the gears together (they seem to stay together as long as the scope is properly balanced). Two, I wrote an "Outburst Detector" for ACP which automatically cuts back on exposure times for variables that are bright.

I upgraded from v3 to v4 of MaxIm DL/CCD and also imaged SN2004et in NGC 6946. There were two visual observing sessions with the 17.5" this month.

The SXV-H9 is the imaging camera, with exposures for variable stars of 120 seconds at 4x4 binning (unguided). This month's session notes are below the overview section.

Monthly Statistics, September 2004
Night	Imaging Time (s)	Exposure Time (s)	# Targets	# Exposures	Variable Star Outbursts/Activity
9/1/04	28206	24360	28	203	V516 Cyg	AR And		IP Peg
9/2/04	29668	25440	27	212	V516 Cyg	AR And
9/3/04	7403	6480	7	54
9/4/04	30551	26280	27	219	V516 Cyg	AR And	FO And	IP Peg
9/5/04	30479	25200	27	210	V516 Cyg	AR And
9/6/04	30889	26280	29	219	V503 Cyg			CY Lyr
9/10/04	31828	27120	32	226	FN And	AR And		CY Lyr
9/11/04	32120	28200	33	235	FN And	AR And		CY Lyr
9/18/04	33103	22940	40	192	V503 Cyg	TY Psc	MR Per
9/19/04	31591	27480	38	229	V503 Cyg	TY Psc	MR Per
9/21/04	21908	19440	17	162	PV And	IW And
9/22/04	14627	12480	20	104		IW And
9/23/04	28863	25080	36	209	V503 Cyg	IW And	MR Per	CY Lyr
9/25/04	35240	20880	35	174	V1113 Cyg	IW And	FS And
9/26/04	24320	16320	25	136	V1113 Cyg
9/27/04	34071	27600	41	230	V1113 Cyg	IW/FS And	MR Per	IP Peg
9/28/04	5810	4920	7	41	FO Per
9/29/04	34481	28320	41	236	FO Per	FO And	FS And	IP Peg
9/30/04	35036	18240	26	152	V344 Lyr
19 nights	520204 (144.50 hr)	413060 (114.74 hr)	536	3443	Activity in 15 stars.

Session Notes

Wed/Thu, September 1/2, 2004

Session from 21:00 to 05:30. I forgot to clear the timers on the attic lights, so the white light in the dome was on for an hour before I discovered it. Fortunately it only ruined data on two stars.

Thu/Fri, September 2/3, 2004

Session from 21:00 to 05:30.

Fri/Sat, September 3/4, 2004

Session from 20:30 to 00:00. The sky clouded over shortly after 23:00 and I finally gave up by midnight.

Sat/Sun, September 4/5, 2004

Session from 20:30 to 05:30.

Sun/Mon, September 5/6, 2004

Session from 20:30 to 05:30. In order to maximize imaging time when doing var stars, I have been imaging during nautical twilight (dawn and dusk). Today I upgraded MaxIm DL/CCD from 3.22 to 4.03 -- it has taken another quantum leap forward! (And my main image processing script doesn't crash anymore!)

Mon/Tue September 6/7, 2004

Session from 20:30 to 05:30. This is the seventh consecutive night that I've been imaging! I've spent most of the time in bed sleeping while ACP runs the show -- I love this setup more and more all the time!

Automation Update : Dec Axis Fix

After reseating the dec gear and cover a few weeks ago and rebalancing the dec axis, the LX-200 has been pointing quite well (almost always within 2 arcmin) and as a result I was able to include an autofocus directive in ACP which worked beautifully (the scope landed on both the focus star and back at the original target).

During the day today, I tested some modifications to the Acquireimages.vbs file for ACP. They ran successfully as part of tonight's run. During a run, ACP now logs the focuser temperature and position after each exposure. At the end of a run, ACP now does the following:

disconnects scope in MaxIm

disconnects focuser in MaxIm

disables dome slaving in DDW

turns dome to home position in DDW

turns off power to scope & camera in DDW

Now, if I could just figure out some way to get ACP to put the cap on the telescope! Bob Denny is currently developing a script to acquire flat frames automatically, so I hope to utilize this too.

Fri/Sat September 10/11, 2004

All-night ACP session. While ACP ran the show up top, I was in the back yard observing variable stars visually with the 17.5" from 22:00 to 01:00.

Sun/Mon September 19/20, 2004

All-night ACP session. While ACP ran the show up top, I was once again in the back yard observing variable stars visually with the 17.5" from 21:00 to 00:00.

Wed/Thu September 22/23, 2004

Automation Update : ACP Outburst Detector

All-night ACP session. Tonight was my first successful run with my modified ACP AcquireImages script (I call it the Outburst Detector) -- this gives dynamic exposure adjustment during a run. What it does is attempts to measure the brightness of the variable star in the first target exposure and throttles back on the exposure time if it is found and is bright.

Now I don't have to use the AAVSO Quick Look page each day to guess exposure times for variables -- another savings of time and effort! Now I simply put the exposure I want to use for each target -- an appropriate one based on the assumption that the target is at its minimum brightness -- and the outburst detector takes care of the rest. After all, there's no point imaging a 13th magnitude star for 30 minutes or more since SNR's above 100 don't buy me anything!

Sat/Sun September 25/26, 2004

All-night ACP session. The dome appears to have gotten lost while tracking V368 Peg (only the second time this has ever happened).

Wed/Thu September 29/30, 2004

All-night ACP session. I interrupted my ACP run to take a few quick images of supernova 2004et in NGC 6946.

Supernova 2004 ET

Scope: 10" f/6.3 LX200, camera: SXV-H9 binned 4x4. Supernova 2004 ET (in crosshairs) in NGC 6946 (exposure: 1x120s).

Thu/Fri Sep/Oct 30/1, 2004

All-night ACP session. Tonight's ACP run was interrupted by fog around 1am (ACP crashed the script after 4 consecutive plate-solve failures). I woke up around 4:30am and took a few more images. What I need is a system for the computer to wake me up in bed if the script crashes!