Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115)
We present new optical observations of V1408 Aql (= 4U 1957+115), the only low mass X-ray binary, black hole candidate known to be in a persistently soft state. We combine new broadband optical photometry with previously published data and derive a precise orbital ephemeris. The optical light curves...
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| Language: | English |
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Czech Technical University in Prague
2015-02-01
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| Series: | Acta Polytechnica CTU Proceedings |
| Online Access: | https://ojs.cvut.cz/ojs/index.php/APP/article/view/2828 |
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| author | P. A. Mason E. L. Robinson S. Gomez J. V. Segura |
| author_facet | P. A. Mason E. L. Robinson S. Gomez J. V. Segura |
| author_sort | P. A. Mason |
| collection | DOAJ |
| description | We present new optical observations of V1408 Aql (= 4U 1957+115), the only low mass X-ray binary, black hole candidate known to be in a persistently soft state. We combine new broadband optical photometry with previously published data and derive a precise orbital ephemeris. The optical light curves display sinusoidal variations modulated on the orbital period as well as large night to night changes in mean intensity. The amplitude of the variations increases with mean intensity while maintaining sinusoidal shape. Considering the set of constraints placed by the X-ray and optical data we argue that V1408 Aql may harbor a very low mass black hole. Optical light curves of UW CrB display partial eclipses of the accretion disk by the donor star that vary both in depth and orbital phase. The new eclipses of UW CrB in conjunction with published eclipse timings are well fitted with a linear ephemeris. We derive an upper limit to the rate of change of the orbital period. By including the newly observed type I bursts with published bursts in our analysis, we find that optical bursts are not observed between orbital phases 0.93 and 0.07, i.e. they are not observable during partial eclipses of the disk. |
| format | Article |
| id | doaj-art-534a7fcedf804527ba99dc89fcd7b931 |
| institution | Matheson Library |
| issn | 2336-5382 |
| language | English |
| publishDate | 2015-02-01 |
| publisher | Czech Technical University in Prague |
| record_format | Article |
| series | Acta Polytechnica CTU Proceedings |
| spelling | doaj-art-534a7fcedf804527ba99dc89fcd7b9312025-08-02T08:02:13ZengCzech Technical University in PragueActa Polytechnica CTU Proceedings2336-53822015-02-0121505410.14311/APP.2015.02.00502596Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115)P. A. Mason0E. L. Robinson1S. Gomez2J. V. Segura3Department of Physics, University of Texas at El Paso, 500 W. University, El Paso, TX, USA, 79902 Department of Mathematics and Physical Sciences, New Mexico State University - DACC, Las Cruces, NM, USA, 88003Department of Astronomy, University of Texas at Austin, 1 University Station C1400, Austin, TX, USA, 78712Department of Physics, University of Texas at El Paso, 500 W. University, El Paso, TX, USA, 79902Department of Physics, University of Texas at El Paso, 500 W. University, El Paso, TX, USA, 79902We present new optical observations of V1408 Aql (= 4U 1957+115), the only low mass X-ray binary, black hole candidate known to be in a persistently soft state. We combine new broadband optical photometry with previously published data and derive a precise orbital ephemeris. The optical light curves display sinusoidal variations modulated on the orbital period as well as large night to night changes in mean intensity. The amplitude of the variations increases with mean intensity while maintaining sinusoidal shape. Considering the set of constraints placed by the X-ray and optical data we argue that V1408 Aql may harbor a very low mass black hole. Optical light curves of UW CrB display partial eclipses of the accretion disk by the donor star that vary both in depth and orbital phase. The new eclipses of UW CrB in conjunction with published eclipse timings are well fitted with a linear ephemeris. We derive an upper limit to the rate of change of the orbital period. By including the newly observed type I bursts with published bursts in our analysis, we find that optical bursts are not observed between orbital phases 0.93 and 0.07, i.e. they are not observable during partial eclipses of the disk.https://ojs.cvut.cz/ojs/index.php/APP/article/view/2828 |
| spellingShingle | P. A. Mason E. L. Robinson S. Gomez J. V. Segura Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115) Acta Polytechnica CTU Proceedings |
| title | Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115) |
| title_full | Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115) |
| title_fullStr | Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115) |
| title_full_unstemmed | Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115) |
| title_short | Optical Photometry of LMXBs: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115) |
| title_sort | optical photometry of lmxbs uw crb ms 1603 260 and v1408 aql 4u 1957 115 |
| url | https://ojs.cvut.cz/ojs/index.php/APP/article/view/2828 |
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