Sandia View Observatory

PX And

Mack — Wed, 30 Nov 2011 23:03:28 +0000

Imaged PX And last night for a little over 5 hours and it displayed an interesting light curve. This is CBA target for the Fall 2011 season.

PX And - 30 Nov 2011

PX And - Night two

Latest observations

Mack — Tue, 29 Nov 2011 05:29:22 +0000

Well, I’ve been using the trial version of ACP Scheduler with my copy of ACP and all I can say is WOW. You just enter target projects and some constraints like what airmass, moonavoid, airmass range, hour angle, etc. and Scheduler will figure out the best time to image and which target to image next.

To test it out I created some target lists of CVs in Pisces, Cassiopeia, Andromeda together with my normal time series targets and inputted this information into Scheduler and turned it on. It was amazing to watch it control everything and prioritize the nights images. I didn’t have to figure out what time to observer what like I use to – which was such a big pain in the ass.

Now I have LOTS of images that I needed to process for photometry. Wondering of a better way to process these images I started using one of the free utility programs from the AAVSO called vPhot. I have greatly increased my production of images to the AAVSO database by using these two programs.

Transformations

Mack — Sat, 12 Nov 2011 21:41:57 +0000

I finally got around to looking at some reference star fields I took images of during the last month or so. I used BVR photometric filters and ran them through Photored, a sub program of MPO Canopus. The M67 star field from Nov 9th looks to have very good data while M67 from the night before seems to have very high extinction and zero points so I’m inclined to think the sky was way less than photometric. I had a Landolt field called SA114 from way back in October and seems to give good results that closely agree to M67 from Nov 9th.

The averaged results from M67 and SA114 are as follows: (error is in quadrature)( CI of B-V)

Tb = 0.0705 σ 0.0150

Tv = -0.0155 σ 0.0050

Tr = -0.0420 σ 0.0125

Tbv = 1.0925 σ 0.0161

k’b = 0.2740 σ 0.0224

k’v = 0.1605 σ 0.0094

k’r = 0.1220 σ 0.0122

CI of V-R:

Tvr = 1.054

Tb = 0.137 σ 0.011

Tv = -0.031 σ 0.007

Tr = -0.085 σ 0.011

The suspicious ZP and extinction numbers from M67 from 8 November was in the range of: k’b = 0.541 k’v =0.716 and k’r = 0.851. the airmass range was good, first set of data was X = 1.13 and second X=2.43 so that had a nice range. I just suspect lots of moisture or dirt in the air.

As M67 is becoming more of target in this fall and winter nights I hope to get more data and check the averages. Some screen shots of the Photored reductions can be seen below:

Tbv

k'b

k'v

k'r

Images not flipped in ACP

Mack — Sat, 12 Nov 2011 03:17:07 +0000

Normally when Astronomers Control Panel, ACP, is controlling your telescope and taking images all night long it does a really nice job of making all the images North up. Since upgrading to TheSkyX I’ve noticed that I have run into a strange thing of some images are not flipped. Trying to follow the instructions in the help file for ACP last night to determine my flip points for configuration I noticed that my Paramount ME was flipping 5 degrees prior to the meridian going East to West. I repeated this numerous times and all the same results. Going West to East it would flip 5 degrees past the meridian. Strange….

After playing around with TheSkyX I noticed there is another meridian reference line on the display. If you click and hold, it highlights and text appears and says Flip HA: xxx. Mine was set to -0.33 or roughly 5 degrees PRIOR to the meridian. Its drag-able so i dragged the line to +0.30 HA which should be about 5 degrees past the meridian. I’m wondering if I clicked and ragged it to some strange place one night. There is now way to turn it off so that you can’t drag it by accident – even asked on the Bisque forums, one day they’ll fix they said.

So, I changed the Flip HA to +0.30HA and changed ACP to track 5 degrees past meridian going East to West and 5 degree priot to meridian when going West to East. This should help. Time and all night runs will tell.

Collecting Photons…

Mack — Mon, 31 Oct 2011 21:13:41 +0000

I’ve been busy collecting time series of a few CVs and some Landolt FoVs over the last few weeks. Some of the CVs I’ve been watching are 1RXSJ 0704+2625, V1032 Cas and 1RXSJ 0636+3535. I got some images of Landolt fields for transformation calculations. I used Landolt FoV SA114 and SA95. The first night data looks promising one night had high STD DeV so I discarded it. I’ll post more on my Transforms laster when I reduce the other nights data and compare.

Polar Alignment refinement

Mack — Mon, 17 Oct 2011 10:43:43 +0000

Tonight I worked on the polar alignment to fine tune it even better than it was. According to the polar alignment analysis of T-point I and now dead on in Azimuth and within 3 arc-seconds of the refracted pole. I had a hard time with the Elevation – kept over shooting it. Attached is a screen shot of T-points analysis.

Here is a 600 second (10min) Protrack image of n1507 after the polar alignment last night. Scale is 1.24″/pix 2258mm focal length.

n1507 600 sec protrack guiding

Temperature compensation

Mack — Sun, 16 Oct 2011 19:29:08 +0000

Ran a 4 hour temperature trend analysis last night. Slewed scope to Zenith and focused on star SAO 70358 and took a sample every 5min and logged the tube temp and the focus position. Plotted this trend in Excel and came up with a temperature coefficient of 73.817 focuser steps per 1C temperature change. Since 1 step of my focuser is 2.177 microns my Aluminum tube changes by 0.161mm/degree*C.

I programmed this into the TCF-S focuser and ran some images without focusing and they stayed in focus quit nicely over the time that I watched them.

Flat tuning

Mack — Mon, 10 Oct 2011 21:35:39 +0000

Looking at the autoflat log from ACP from 3 October and a message posted by Taimur Khun I followed his lead to fine tune the flat image taking config file. Here is the Excel 2010 file on my pretty picture filters. I derived an acceleration of 0.86 instead of the default 1.0. The next time I make flats I’ll have to compare the efficiency between the two.

(Contains 1 attachments.)

OT2147+2445 first night

Mack — Mon, 10 Oct 2011 19:38:11 +0000

I tried to get a night of observations of this Optical Transient OT2147+2445 but the skies went from clear to full over cast in about 1.5hrs. Out of 190 30 second images only about 80 were usable. The hour of images I managed to reduce showed a gentile brightening.

tpoint fine tuning

Mack — Wed, 05 Oct 2011 20:59:40 +0000

Looking at a screen shot of my 505 point tpoint run from a few weeks ago I was wondering if I could reduce the size of some of the terms.

The MA and ME terms should be the easiest to reduce since they are the error in the polar alignment. For the MA error I need to rotate my mount 43.6 arc-seconds West or 0.4 knob ticks on the Paramount ME. For the ME error I need to raise my mount elevation 24 arc-seconds or 0.2 knob ticks on the mount. Should be easy… least in theory.

The IH, index error in Hour Angle term is quite large. I wonder if the time or initial sync was off that much? Could be my longitude is incorrect. I need to take a new GPS reading for the observatory also.