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Charts, Charts, Charts...

Posted by SXN on March 7, 2011 - 12:34pm

 

Every few years or so, the dining room table in my house becomes “AAVSO Variable Star Charts Central”. The centerpiece, placemats and silverware are put away, and in their place are three ring binders, plastic page protectors and stacks of paper charts. The printer in my office gets a workout, and I become a regular at the office supply store, buying ink, paper and other supplies as the project progresses.
 
This is the fifth time in ten years I have performed this major renovation project, so I’ve got it down to a science now. I’ve kept most of the charts that have been replaced, so it has become a sort of archival history project too.
 
When I first started observing, I started with all the stars in David Levy’s book A Guide to Variable Stars. I used everything I could lay my hands on. Old "micro-dot" charts, preliminary charts, and a few new format charts that I would have to hold upside-down and shine a flashlight through to match the view in the eyepiece. In 1998, not everything in the chart catalog was online yet, and only a small percentage of the charts were available as reversed charts for use with a Schmidt-Cassegrain. It wasn’t long before my observing program became all the stars with available reverse charts. That was a lot easier than using the flashlight trick or trying to flip them in your head. 
 
I realized immediately that I would need to organize all these charts into binders to keep them protected from the dew, frost, and wind. My system evolved quickly, and it hasn’t changed much over the years. I printed wide field finder charts from planetarium software with a limiting magnitude of about 9 that had a circle indicating the size of my finder scope field of view, and a little arrow pointing to my ‘jumping off star’. This was the star I would aim for when dialing in the setting circles or star-hopping to the next target. The same star would be indicated on the variable star chart so when I got to the eyepiece I could find my way to the variable star by star-hopping from there.  
 
In the binder, the finder chart was on the left and the variable star chart on the right. Simple for most CVs, I usually only needed one comparison chart. Each time I flip the page I'm on a new star. Mira stars with large amplitudes usually require additional charts. Typically, B charts for maxima above 9th mag, which I observe using the finder scope, D charts for 10-13th mag and E charts for fainter than 13th mag or to relieve crowding on some D charts. Some Milky Way fields require F charts to relieve the crowding of comp star labels or to show 15th magnitude comps.
 
The second generation of charts began with me printing reversed star fields from planetarium software and hand labeling the magnitudes, but I always hated the messy look of my handwriting on these charts and they were limited by the contents of the Guide Star Catalog, so they didn’t last long. Once the complete AAVSO chart catalog became available online, I started downloading all the charts and flipping the fields and labels around in an art program. I think that was when the true chart madness set in. I couldn't decide what to observe, so I decided to observe everything! I made hundreds and hundreds of charts in various scales and orientations. 
 
My CV binders stayed more or less unchanged for a long time once I had maximized the order for speed. That was an interesting project. I took day-glow stickers and labeled them with the names of all my CVs then placed them on their respective pages of Sky Atlas 2000 so I could figure out the most efficient order to observe them in. I recently read a paper on ACP Scheduler and was pleased to see I had followed the same logic as the software in assigning the observing order. I just did it the old-fashioned analog way. The same way I was observing. 
 
Using those binders I was able to observe 100+ CVs on a decent night. I did over 250 in a night a few times. It’s easy when all you are doing is reporting, “it isn’t in outburst”. But I have to admit 250 is just insane.
 
 
In 2003, I began coordinating chart production at AAVSO and we started the last major overhaul of the chart catalog before VSP came online. By 2005, I had replaced all my previous charts with the new ones we were making using Henden and ASAS photometry. Until recently, I still preferred these charts to anything the chart plotter could produce. They were beautifully crafted, hand labeled and thoroughly checked before being released to the public. But there was no way we could continue that practice and keep up with the pace of new discoveries or the demand for more and better charts.
 
By 2009, we had revised a significant percentage of the sequences with newer, better photometry and it was time to bring the binders back indoors from the observatory for another update. Not only that, but now I had a CCD on another telescope in a new roll off and I needed a whole different set of charts for those program stars!
 
With the latest round of improvements to VSP most of my previous objections to the charts it produces have been eliminated. First among these were the ridiculous huge star dots it used to plot for many variables! I have hated those blobs for years. So here we are again, updating all the chart binders and revising the observing programs again.
 
My visual program is now going to concentrate on AAVSO Legacy and Program LPVs. I want to observe stars I can make positive estimates of 99% of the time. I have tens of thousands of “fainter than” observations in the AID and I don’t find them that much fun to make any more. So I have several binders with all new LPV charts for the eyepiece.
 
My CV program will just be the prototypes, legacy CVs, bright active stars and a few favorites I will observe forever just because I like them. I’m pretty sure I will never sit out all night under the stars and report “I didn’t see it” 100 times ever again. Let someone else discover the next outburst of PQ And. I want to make observations you can plot on a light curve.
 
I have another binder for the CCD scope. That program is Z CamPaign stars, northern RCB, recurrent novae and some quirky favorites. I affectionately call them my ‘oddball' program stars.
 
Well, time to go. The printer has grown quiet, so I either have another batch of charts to organize, or I’m out of paper. Until next time…

Comments

Hi Mike,

 

Nice to see that I followed exactly the same way you did it. Although a few years later. I also had my charts in the same way organized, had a "start" star for starhopping and placed all the stars on a skyatlas so I could figure out the best way to observe them. I also had + 500 charts of mirastars and well known cv's in my binders. My best night were 160 observations of mirastars in one night. If I remember it was a 7 hour observing run.

 

The last two years I have done no visual observing anymore because I also went to CCD. But the fever is coming back. I planning to buy a 12" Dobson and observe visually while the CCD is working. My program will be this time only cv's because they're easy. But maybe the mirafever come's back.:)

 

Clear skies, Hubert

http://www.vvs.be/wg/wvs/

I find I use a similar system but customized for my work.

My program is built around the Bulletin stars with a smattering of my own personal "Legacy" stars and others of interest.

The month following the release of the Bulletin in Feb is followed by a frantic update. I use Dec -55 d as my southern limit and try to select stars bright enough for positive observations- although some stars such as R CrB earlier in its current fade or R Com at min still result in "Fainter Than" observations.

I use the standard a thru e scales which gives me limiting magnitude for my 12" dob- generally fainter than 14.0 to 14.2 on a good night and 14.8 on the best nights. I could probably dispense with a lot of the d and e scale charts- especially with the big blobs on the e scale but I do need the e scale at times on some stars and just have these for consistency. 

Dave M.

A list of your northern hemisphere CCD stars and "odd balls" would be interesting to see...  PKV

Northern NR

V0529 Ori

05 58 20.15 +20 15 45.4

NR:

6: - <11 V

T CrB

15 59 30.16 +25 55 12.6

NR

2 - 10.8 V

U Sco

16 22 30.78 -17 52 42.8

NR+E

7.5 - 19.3 V

V1195 Oph

17 00 21.67 -20 53 33.5

NR:

16.3 - <20.1 p

V2487 Oph

17 31 59.81 -19 13 55.6

NR

9.5 - 17.7 p

RS Oph

17 50 13.17 -06 42 28.6

NR

4.3 - 12.5 V

CI Aql

18 52 03.59 -01 28 39.3

NR+E

8.6: B - 16.8 V

Northern RCB

DY Per

02 35 17.10 +56 08 45.0

10.6 - <13.2 V

SU Tau

05 49 03.70 +19 04 22.0

9.1 - 16.86 V

MV Sgr

18 44 32.00 -20 57 13.0

12 - 16.05 B

FH Sct

18 45 14.80 -09 25 36.0

13.4 - 16.8 p

SV Sge

19 08 11.80 +17 37 41.0

11.5 - 16.2 p

V1157 Sgr

19 10 11.80 -20 29 42.0

11.5 - <14.5 V

ES Aql

19 32 21.62 -00 11 30.9

11.5 - <17.7 V

V0482 Cyg

19 59 42.60 +33 59 28.0

11.8 - <15.5 p

U Aqr

22 03 19.70 -16 37 35.0

10.5 - <14.4 p

UV Cas

23 02 14.70 +59 36 37.0

11.8 - 16.5 p

Z Cams

Name  Coords (J2000)  Const.  Var. type  Period  Mag. range
V0513 Cas 00 18 14.90 +66 18 14.0 Cas UGZ: -- 15.5 - <17.2 p
IW And 01 01 08.90 +43 23 26.0 And UGZ -- 14.2 - 17.4 p
RX And 01 04 35.50 +41 17 58.0 And UGZ -14 10.3 - 14 V
TW Tri 01 36 37.00 +32 00 40.0 Tri UGZ -28 13.3 - 17.0 p
KT Per 01 37 08.50 +50 57 20.0 Per UGZ+ZZ -26 11.5 - 15.39 V
TZ Per 02 13 50.90 +58 22 53.0 Per UGZ -17 12 - 15.6 V
V0368 Per 02 47 32.60 +34 58 28.0 Per UGZ: -- 15.2 - <17.5 p
PY Per 02 50 00.10 +37 39 23.0 Per UGZ -- 13.8 - 16.5 p
BI Ori 05 23 51.80 +01 00 30.0 Ori UGZ -20.5 13.2 - 16.7 p
WZ CMa 07 18 49.20 -27 07 43.0 CMa UGZ: -27.1 14.5 - <16.0 p
BX Pup 07 54 15.60 -24 19 36.0 Pup UGZ -18 13.76 - 16 V
Z Cam 08 25 13.20 +73 06 39.0 Cam UGZ -22 10 - 14.5 V
AT Cnc 08 28 36.90 +25 20 03.0 Cnc UGZ -14 12.3 - 14.6 p
SY Cnc 09 01 03.30 +17 53 56.0 Cnc UGZ -27 10.6 - 14.0 p
AH Her 16 44 10.00 +25 15 02.0 Her UGZ -19.8 10.9 - 14.7 p
UZ Ser 18 11 24.90 -14 55 34.0 Ser UGZ -26.4 12.0 - 16.7 p
V0391 Lyr 18 21 12.00 +38 47 44.0 Lyr UGZ (100:) 14.0 - 17.0 p
HS 1857+7127 18 57 20.40 +71 31 19.2 Dra UGZ+E -- 13.9 - 17.2
V0868 Cyg 19 29 04.40 +28 54 26.0 Cyg UGZ -20.38 14.3 - <17.8 p
V1505 Cyg 19 29 49.00 +28 32 54.0 Cyg UGZ -- 15.2 - <17.5 p
EM Cyg 19 38 40.10 +30 30 28.0 Cyg UGZ+E -- 11.9 - 14.4 p
FY Vul 19 41 40.00 +21 45 59.0 Vul UGZ -- 13.4 - 15.33 B
AB Dra 19 49 06.40 +77 44 23.0 Dra UGZ -13.4 11 - 15.3 V
V1363 Cyg 20 06 11.60 +33 42 38.0 Cyg UGZ -- 13.0 - <17.6 p
IS Del 20 31 09.60 +16 23 10.0 Del UGZ: -- 15.0 - <17.5 p
VW Vul 20 57 45.10 +25 30 26.0 Vul UGZ -30 13.1 - 16.27 B
V1404 Cyg 21 57 16.40 +52 12 00.0 Cyg UGZ -19.15 15.7 - <17.7 p
MN Lac 22 23 04.60 +52 40 58.0 Lac UGZ -- 15.1 - <18.0 p
HX Peg 23 40 23.70 +12 37 42.0 Peg UGZ -- 12.9 - 16.62 V

I use a similar system for my charts. On a 8-1/2 x 11 in landscape format, I have an A and B sized chart placed side by sidewith the respective variable identified by a circle. I identify a 4th to 6th magnitude guide star on each chart and link it with a line between the charts. This gives me a quick and easy way to spot the guide star with my finder scope. I mark recognizable asterisms, or a path to star hop from the guide star to the variable.  On the backside of the chart I have a full sized 'd' sized chart. 

My productivity at the eyepiece has improved since using these charts.

WVR

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484