Video Method for Observing Eclipsing Binaries Hristo Pavlov
Video Method for Observing Eclipsing Binaries Hristo Pavlov VSS Symposium 4, 25 Mar 2016 NACAA XXVII
Introduction Occultation Observer Since 2007 Contributor to ASCOM Video Contributor to ADVS and TACOS-BD systems Author of Free Open Source Astronomical Software (Occult. Watcher 2007 -present, Tangra 2009 -present, Occu. Rec 2013 -present) International Occultation Timing Association (IOTA) Member Since 2010 Observing from Tangra Observatory (MPC Code E 24) AAVSO Member and Variable Star Observer Since Dec, 2014
Collaboration Anthony Mallama, US Brian Loader, NZ Stephen Kerr, AU
Why Video? 1. Cheaper 2. Capable 3. Used by the ‘right’ people
How is Video Different? �More noise �Order of magnitude more data points �Video is 8 bit �Video may be non linear �Not good for calibrated photometry �Accuracy of 0. 02 mags rather than 0. 001 mags �Timing unaffected �Good for timing light curves
Video Technique �JAAVSO Paper https: //www. aavso. org/ejaavso 299 �Video TOMs O-C Difference CG Pup: 0. 00016 days ER Ori: 0. 00074 days
Tangra Light Curves
Data Reduction: Kwee-van-Woerden Final HJD result Kwee-van-Woerden solution 1. Choose 2. 3. roughtly Select 4. the equal starwings for HJD (important correction for Kv. W)
Timing Error Visualisaion +/-0. 005 days +/-0. 001 days Tangra’s EB Kv. W add-in error estimate for the above light curve was +/- 0. 0004 days
Program for 2015 �Develop a Video Technique �Obtain TOMs of short-periodic southern hemisphere variables �Revise ephemeris where needed �Identify interesting stars for follow up � 78 stars observed � 3 papers published in JAAVSO
Published TOMs of 50 Stars � WZ Ant � SY Aps � V 653 Ara � EZ Car � GW Car � PX Car � BD Cen � OV Cen � V 576 Cen � V 606 Cen � V 676 Cen � V 689 Cen � V 752 Cen � TW Cet � RW Cr. A � V 405 Cr. A � V 634 Cr. A � AC Cru � BF Cru � TW Cru � RW Dor � CI Eri � RV Gru � SZ Hor � RY Ind � FT Lup � TW Mus � ER Ori � LT Pav � MU Pav � NP Pav � RW Ps. A � AY Pup � DS Pup � CG Pup � UX Ret � RT Scl � V 833 Sco � RS Sct � V 902 Sgr � V 743 Sgr � V 1071 Sgr � V 1647 Sgr � GN Tr. A � DS Vel � BF Vel � EQ Vel � EU Vel � FM Vel � FQ Vir
Revised Ephemeris
Revised Ephemeris, Cont.
Period Change of V 752 Cen
Period Change of RW Ps. A
Unpublished TOMs of 28 Stars � V 659 Ara � IR Car � QR Car � V 625 Car � BH Cen � V 349 Cen � V 593 Cen � V 672 Cen � RZ Col � TZ Cra � AQ Cru � CT Eri � RV Gru � SY Hor � ST Ind � IT Lib � TV Mus � SV Nor � SZ Nor � V 1010 Oph � HY Pav � YZ Phe � WW Phe � GY Pup � GZ Pup � SZ Scl � V 843 Sco � V 1177 Sgr � V 2617 Sgr
Call for Observations and VSS Collaboration �Program for 2016: Obtain more TOMs of identified interesting stars (see previous slide) �Observations don’t have to be done by Video �VSS - Video Group ? �VSS - Short Periodic EB Project ?
Questions?
- Slides: 18
