BAA VSS Oct 14th 2011

 Data collected from 25/10/2003 to 30/3/2008  This during 76 nights  In between Cygnus work of higher priority  25,000 images, 21,000 pass quality tests  Longest night 11-1/2/ hrs 31mins  Start at el=45.6° to 79.9° and down to 16.7° BAA VSS Oct 14th 2011

Location in Auriga capella BAA VSS Oct 14th 2011

 Started October first two years gaining experience  66,400 quality-filtered images since Aug 2003 in main Cygnus area (area ‘a’)  But also some data in 8 contiguous areas in Cygnus (10,000)- Each 2.8 degrees square, 7.84 sq. Degrees  Plus 25,000 in Auriga (total area 86 sq. degrees)  The area ‘a’ has more than 220,000 measurable stars  17,000 of those have 5 year light curves  1022 variable stars found in area ‘a’ so far BAA VSS Oct 14th 2011

 Outline of data pipeline  Ways of finding variable stars with examples  So far (11/10/11) I’ve found 178  63 eclipsing binaries, 64 slow variables  37 fast variables, 1 Cepheid, 13 misc  Six of those are in the GCVS BAA VSS Oct 14th 2011

 Collect data- 1 image every 46seconds  Rename files- Fits convert-extract time info  Convert to APL, x10, dark subtraction, flat division  Find brightest 6,000 stars, quality assessment, log data -vimp  Calculate picture coefficients (144 stars, 4 th order poly, 16 coefficients)  Probe images at starlist ra, dec positions* (60,000 or 28,000)  Collect pixel sets for each star, add to previous and store- singlesets  Collect average sets, 2401 per image, 20 images averaged *Probing by ra and dec allows us to make average sets centred at fixed ra/dec and also to observe any large-enough proper motions. BAA VSS Oct 14th 2011

 Store Fits and processed images  Probe pixel-sets to create diameter sets  Each star is measured at in 14 diameters  3x3 pix and 4 to 16 diameter  Noise is measured in quiet dates and optimum diameter evaluated  Each star is then ratioed to each of 10 local comparison stars BAA VSS Oct 14th 2011

 At this point a number of obvious variable stars pop out  So, re-evaluate the star ratios  Repeat a few times  End result: good light curves for all stars with several comparison stars for each BAA VSS Oct 14th 2011

 For the Auriga data these are 20,086 x14 magnitude values from 76 dates  From a nominal 28,738 stars  8.08 billion data values  Explain nominal! BAA VSS Oct 14th 2011

 Fast noise  Slow noise  Scattery noise  Spiky noise  Overlay analysis  Fourier Analysis  Star colour hints BAA VSS Oct 14th 2011

735 data points- rms 14.5 mmag BAA VSS Oct 14th 2011 This is the image to image variation

735 data points BAA VSS Oct 14th 2011

SD 15.8mmag

SD 3.1 mmag BAA VSS Oct 14th 2011

Mag 13.8 not var Mag 13.8 varMag 15.4 var

diameter star BAA VSS Oct 14th 2011 In mmags

BAA VSS Oct 14th 2011

Star pixels square star 418 BAA VSS Oct 14th 2011

Each of 76 dots is the average of one night The rms variation over those 1619 days is 12mmag BAA VSS Oct 14th /4 2005/6 2006/7 2007/8

BAA VSS Oct 14th 2011

GCVS Variable Stars in Stan’s Auriga Area StarTypem P (d) Sp. myid SX AurEB B3 V+ B5 V 41 SY AurDCEP F5-F8 61 ER AurDCEP V414 Aur Be B2 Vne 27 V425 AurEB B5 12 V489 AurLB: BAA VSS Oct 14th 2011

My range is gcvs is 0.66 BAA VSS Oct 14th 2011

Range 0.46mag---- gcvs is 0.63 mag BAA VSS Oct 14th 2011

STARE iras STARE CGCS iras STARE CGCS CGCS STARE CGCS STARE STARE STARE STARE STARE CGCS BAA VSS Oct 14th found so far

CGCS iras CGCS STARE CGCS STARE STARE STARE STARE STARE iras STARE CGCS CGCS STARE STARE BAA VSS Oct 14th 2011

Carbon star CGCS 878 BAA VSS Oct 14th 2011

V V575? V V Slow Red Variables in Cygnus area ‘a’ Star id magr starid magr BAA VSS Oct 14th 2011

 Fast noise  Slow noise  Scattery noise  Spiky noise  Overlay analysis  Fourier Analysis  Star colour hints BAA VSS Oct 14th 2011

4 years data BAA VSS Oct 14th 2011

4 years data BAA VSS Oct 14th 2011

4 years data BAA VSS Oct 14th 2011

star period star period star period star

 Good at the fast ones  Only one long night needed  But three is better  I used and 2211 which are  10/12/2005 and 11/1, 20/  and 11.6hrs long  Longest: el=45.6° to 79.9° down to 16.7°  It’s very quick – 28,000 stars in 40mins BAA VSS Oct 14th 2011

yes yes yes First, I tried looking at those where 6th or higher harmonic dominated: 37 found so far- incomplete BAA VSS Oct 14th 2011

Auto scan criterion: peak> 5 times 90%rms BAA VSS Oct 14th 2011

cycles/day amplitude 29mmags BAA VSS Oct 14th 2011

cycles/day amplitude 137 mmags BAA VSS Oct 14th 2011

ER Auriga --DCEP BAA VSS Oct 14th 2011

4 yr plot BAA VSS Oct 14th 2011

1171 Red squares-Cepheid Green Triangle –W VIR

BAA VSS Oct 14th 2011

According to the Catalogue of Components of Double and Multiple Stars (CCDM) of Dommanget et al. (2002), this is a visual binary star with r = 0.2”, q = 16°, and with V 1 = V 2 = 9.5.///// Hartkopf et al. (1994), in ‘ICCD speckle observations of binary stars’ give r = 0.211”, q = 356.7° for the epoch ///////The Washington Visual Double Star Catalogue (Mason et al., ) gives r = 0.3”, q = 27° for the epoch This yields dq / dt = °/yr  P ~ 1000 yr. On the present information, we see the visual binary orbit roughly face-on (i « 90°), so the orbit is not co- planar with the orbit of the eclipsing binary, which, of course, must be nearly edge-on (i ~ 90°).

BAA VSS Oct 14th 2011 THE END