David Conner's astronomy notes
  • Home
  • Eclipsing binary light curves
  • Other light curves
  • Discoveries
  • Somerby Observatory
  • Light curve of NSV 12716, David Conner and Josef Kalášek.
  • Contact
  • Eclipsing binaries drop down list
    • AB Andromedae
    • AC Bootis
    • AD Andromedae
    • AD Bootis
    • AI Draconis
    • AK Herculis
    • AP Leonis
    • AR Lacertae
    • ASAS J192916+4637.3
    • AW Lacertae
    • AZ Cassiopeiae
    • BB Cephei
    • BD Canis Majoris
    • BF Aurigae
    • BM Cassiopeiae
    • BM Orionis
    • BX Andromedae
    • CD Andromedae
    • CM Lacertae
    • CQ Aurigae
    • CQ Serpentis
    • DM Persei
    • DO Cassiopeiae
    • DS Andromedae
    • EE Cephei
    • EE Pegasi
    • EF Canis Majoris
    • EG Cephei
    • EI Cephei
    • EO Aurigae
    • ER Orionis
    • ET Bootis
    • GK Cephei
    • GO Cancri
    • HL Aurigae
    • IM Aurigae
    • IQ Persei
    • IU Aurigae
    • IY Aurigae
    • IZ Persei
    • KU Cygni
    • LW Puppis
    • LY Aurigae
    • LY Delphini
    • NO Leonis
    • NS Draconis
    • OO Aquilae
    • OT Bootis
    • OW Geminorum
    • RS Canum Venaticorum
    • RW Geminorum
    • RW Tauri
    • RX Cassiopeiae
    • RX Herculis
    • RZ Cassiopeiae
    • RZ Comae Berenices
    • RZ Eridani
    • RZ Ophiuchi
    • S Equulei
    • ST Aquarii
    • SU Aquarii
    • SV Camelopardalis
    • SW Lacertae
    • SX Aurigae
    • SX Cassiopeiae
    • SY Andromedae
    • SZ Piscium
    • TT Aurigae
    • TU Lyncis
    • TV Cassiopeiae
    • TW Andromedae
    • TW Cancri
    • TW Cassiopeiae
    • TW Draconis
    • TX Cassiopaiae
    • TX Ursae Majoris
    • TZ Lyrae
    • U Cephei
    • U Coronae Borealis
    • U Ophiuchi
    • u Herculis
    • UU Cancri
    • UV Leonis
    • UZ Cygni
    • UZ Leonis
    • V346 Aquilae
    • V367 Cygni
    • V 371 Cygni
    • V448 Cygni
    • V451 Ophiuchi
    • V453 Cygni
    • V477 Cygni
    • V505 Monocerotis
    • V523 Cassiopeiae
    • V530 Cygni
    • V566 Ophiuchi
    • V698 Cygni
    • V836 Cygni
    • V1171 Cygni
    • V1425 Cygni
    • V1765 Cygni
    • V2483 Cygni
    • V3288 Ophiuchi
    • V Serpentis
    • VW Cephei
    • W Serpentis
    • W Ursae Majoris
    • WW Aurigae
    • WY Cancri
    • X Trianguli
    • XY Sagittarii
    • Y Cygni
    • Z Herculis
    • ZZ Bootis
    • ZZ Cancri
    • ZZ Cephei
  • Other light curves drop down list
    • BE Serpentis
    • chi Cygni
    • GW Ursae Majoris
    • HD189733
    • HP Lyrae
    • NSV 12716
    • RU Sextantis
    • V1423 Cygni
    • V3908 Sagittarii
    • V5102 Sagittarii
    • YY Andromedae
  • Discoveries drop down list
    • GSC 02259-00741
    • GSC 02259-00970
    • GSC 02664-00187
    • GSC 02664-00763
    • GSC 02679-00311
    • GSC 02681-01041
    • GSC 02683-02642
    • GSC 02699-00921
    • GSC 02763-02208
    • GSC 02764-00623
    • GSC 02907-00103
    • GSC 02916-00275
    • GSC 02916-01167
    • GSC 02924-02382
    • GSC 03362-01863
    • GSC 03481-01448
    • GSC 03653-00917
    • GSC 04024-00551
    • GSC 04024-01267
    • HD 227877
    • HD 332629
  • Light pollution
  • Observing Eclipsing Binaries Using Remote Observatories

RW Tauri / RW Tau

RW Tauri is an EA type eclipsing binary with an interesting o-c curve (Kreiner et al).  It has been suggested that the system involves mass transfer between the components (Plavek, Dobias 1983).

The fact that the period of this star is not constant, but sometimes increases and sometimes decreases, results in calculated minima becoming more and more in error with observations.  Depending on which data is used (GCVS, AAVSO VSX, BAAVSS, AAVSO) the calculated minima can differ by almost two hours.

It was one of my program stars with The Bradford Robotic Telescope.  Before the demise of this observatory, I acquired 28 images with the Cluster Camera ('green' filter)  between 2014 October 14 and 2016 October 1.  The photometry of RW Tau from these images is plotted in the following light curve.

Picture
RW Tau has a catalogued period of 2.768783 d  with an epoch in 2002 (Kreiner), or 2.7688356 d  with an epoch in 1983 (AAVSO VSX , GCVS).

Using my derived time of a minimum (from 5 data points!) of ~HJD 2457390.57782 and Kreiner's value for the period I managed to take a number of images of RW Tau through breaks in the cloud from Somerby Observatory on 2016 November 10 with the 2" Titan.  These observations were all during the total phase of the eclipse.
Picture
This star is currently (November 2016) the subject of a BAA VSS project.

A primary minimum observed from Somerby Observatory on 16 November 2017 with the 2" Titan.  225 unfiltered images were reduced to produce the following light curve.  The HJD time of minimum was calculated in Peranso..
Picture
Picture
The time of minimum was HJD 2458074.463457 +- 0.000026d.  

​This compares to the following predicted times (accessed 16 November 2017)
​BAAVSS 17 (22) 26
Kreiner et al 23h 11m
DSC/BRT 23h 13m
AAVSO VSX 23h 14m
Observed 23h 07m  = HJD 2458074.463457

Combining these results with the BRT observations produces the following light curve and phase diagram.
BRT observations in black, 2" Titan observations in red.
Picture
Picture

​The differing predicted times of eclipse will probably be due to the rapidly changing period with different authors using different periods and epochs in their predictions.  At the time of writing (13 December 2017) the catalogued values for the period are 2.7688356d (GCVS), 2.768804d (AAVSO VSX) and  2.768796​d (Kreiner)

​[Page updated 2017 December 13]
Powered by Create your own unique website with customizable templates.