Planetary Transit Candidates in the Cstar Field: Analysis of the 2008 Data

Wang, Songhu; Zhang, Hui; Zhou, Jingjing; Xu, Zhiyong; Yang, Ming; Wang, Lifan; Bayliss, Daniel; Zhou, George; Ashley, M. C. B.; Zhang, Fan; Feng, Li Ying; Gong, Xuefei; Lawrence, Jon; Liu, Hui-Gen; Liu, Qiang; Luong-Van, D.; Ma, Jun; Meng, Zeyang; Storey, J. W. V.; Wittenmyer, Robert A.; Wu, Zhenyu; Yan, Jun; Yang, Huigen; Yang, Ji; Jun, Yang; Yuan, Xiangyan; Zhang, Tianmeng; Zhu, Zhenxi; Zou, Hu

doi:10.1088/0067-0049/211/2/26

Cited by 47 publications

(17 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The highly irregular PSF shape caused trouble for many stellar detection algorithms such as DAOPHOT's FIND, which would detect a single source multiple times in neighboring pixels while skipping other sources entirely. Therefore, we visually identified a total of 2086 sources in our g reference frame that were always contained in the field of view and we included the transformed coordinates of the 165 variable stars previously detected by Wang, L. et al (2011Wang, L. et al ( , 2013; Wang, S. et al (2014). The area of continuous coverage in our reference frames spans a 450 pixel (1.875…”

Section: Flux Extractionmentioning

confidence: 99%

“…We also included previously-detected variable stars located in our reference frames from Wang, L. et al (2011Wang, L. et al ( , 2013 (158 in g, 158 in clear and 159 in r ) and transiting exoplanet candidates from Wang, S. et al (2014) (2 in g, 3 in clear and 3 in r ) for a total of 2246 stars in g, 2241 stars in clear and 2248 stars in r.…”

Section: Scintillation Noisementioning

confidence: 99%

“…Previous studies of the photometry using aperture photometry from the 2008 and 2010 winter seasons have shown remarkable clarity, coverage and precision (Zou et al 2010;Zhou et al 2010b;Wang, L. et al 2011Wang, L. et al , 2013. More than 200 variable stars with i < 15.3 mag were categorized including exoplanet candidates, Blazhko-effect RR Lyraes, a possible type II Cepheid in an eclipsing binary system and a star with regular milli-magnitude variations on extremely short timescales (Wang, L. et al 2011(Wang, L. et al , 2013Wang, S. et al 2014).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Difference Image Analysis of Defocused Observations With Cstar

Oelkers

Macri

Wang

et al. 2015

Self Cite

View full text Add to dashboard Cite

, during which the system also suffered from intermittent frosting and power failures. Despite these technical issues, nearly 800,000 useful images were obtained using g, r & clear filters. We developed a combination of difference imaging and aperture photometry to compensate for the highly crowded, blended and defocused frames. We present details of this approach, which may be useful for the analysis of time-series data from other small-aperture telescopes regardless of their image quality. Using this approach, we were able to recover 68 previously-known variables and detected variability in 37 additional objects. We also have determined the observing statistics for Dome A during the 2009 winter season; we find the extinction due to clouds to be less than 0.1 and 0.4 mag for 40% and 63% of the dark time, respectively.

show abstract

Section: Flux Extractionmentioning

confidence: 99%

Section: Scintillation Noisementioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Difference Image Analysis of Defocused Observations With Cstar

Oelkers

Macri

Wang

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Various efforts have been made to reduce the systematic errors and to push the photometric precision below a few mmag, including the modeling of the inhomogeneous effects of clouds (Wang et al 2012), the ghost images (Meng et al 2013), and the systematic diurnal residuals (Wang et al 2014b). Based on the detrended light curves obtained during the 2008 winter season, comprehensive studies on exoplanet candidates (Wang et al 2014a), stellar variability , eclipsing binaries (Yang et al 2015), and stellar flares (Liang et al 2016) were carried out. Other independent studies include those on variable sources (Wang et al 2011(Wang et al , 2013Oelkers et al 2015), and specific studies on the pulsation modes of RR Lyrae stars (Huang et al 2015) and δ Scuti variables based on the CSTAR observations in single or multiple years from 2008 through 2010.…”

Section: Introductionmentioning

confidence: 99%

Optical Sky Brightness and Transparency during the Winter Season at Dome A Antarctica from the Gattini-All-Sky Camera

Yang

Moore

Krisciunas

et al. 2017

Self Cite

View full text Add to dashboard Cite

The summit of the Antarctic plateau, Dome A, is proving to be an excellent site for optical, near-infrared, and terahertz astronomical observations. Gattini is a wide-field camera installed on the PLATO instrument module as part of the Chinese-led traverse to Dome A in 2009 January. We present here the measurements of sky brightness with the Gattini ultra-large field of view ( ´ 90 90 ) in the photometric B-, V-, and R-bands; cloud cover statistics measured during the 2009 winter season; and an estimate of the sky transparency. A cumulative probability distribution indicates that the darkest 10% of the nights at Dome A have sky brightness of S B =22.98, S V =21.86, and S R =21.68 mag arcsec −2 . These values were obtained during the year 2009 with minimum aurora, and they are comparable to the faintest sky brightness at Maunakea and the best sites of northern Chile. Since every filter includes strong auroral lines that effectively contaminate the sky brightness measurements, for instruments working around the auroral lines, either with custom filters or with high spectral resolution instruments, these values could be easily obtained on a more routine basis. In addition, we present example light curves for bright targets to emphasize the unprecedented observational window function available from this ground-based site. These light curves will be published in a future paper.

show abstract

“…The Chinese Antarctic Kunlun station (south 80°25′01″, east 77°06′58″), which is 7.3 km away from Dome A in the southwest, is currently hosting two wide-field telescopes with aperture of 500mm (the Antarctic Survey Telescopes; Yuan et al 2008) and will be developed to support more astronomical facilities in the near future. The survey of transiting extrasolar planets, taking advantage of the continuous darkness and large clear-sky fraction (>90%; Zou et al 2010;Law et al 2013;Wang et al 2014) in the winter months, is one of the main scientific goals at Kunlun station.…”

Section: The Bright Star Survey Telescope In Antarcticamentioning

confidence: 99%

Searching for the Transit of the Earth-mass Exoplanet Proxima Centauri b in Antarctica: Preliminary Result

Liu

Jiang

Huang

et al. 2017

Self Cite

View full text Add to dashboard Cite

ProximaCentauri is known as the closest star to the Sun. Recently, radial velocity (RV) observations revealed the existence of an Earth-mass planet around it. With an orbital period of ∼11 days, Proxima Centauri b is probably in the habitable zone of its host star. We undertook a photometric monitoring campaign to search for its transit, using the Bright Star Survey Telescope at the Zhongshan Station in Antarctica. A transit-like signal appearing on 2016 September 8 has been tentatively identified. Its midtime, T C =2,457,640.1990±0.0017 HJD, is consistent with the predicted ephemeris based on the RV orbit in a 1σ confidence interval. Time-correlated noise is pronounced in the light curve of ProximaCentauri, affecting the detection of transits. We develop a technique, in a Gaussian process framework, to gauge the statistical significance of a potential transit detection. The tentative transit signal reported here has a confidence level of 2.5σ. Further detection of its periodic signals is necessary to confirm the planetary transit of ProximaCentaurib. We plan to monitor ProximaCentauri in the next polar night at DomeA in Antarctica, taking advantage of continuous darkness. Kipping et al. reported two tentative transit-like signals of ProximaCentaurib observed by the Microvariability and Oscillation of Stars space telescope in 2014 and 2015. The midtransit time of our detection is 138minutes later than that predicted by their transit ephemeris. If all of the signals are real transits, the misalignment of the epochs plausibly suggests transit timing variations of ProximaCentaurib induced by an outer planet in this system.

show abstract

Planetary Transit Candidates in the Cstar Field: Analysis of the 2008 Data

Cited by 47 publications

References 54 publications

Difference Image Analysis of Defocused Observations With Cstar

Difference Image Analysis of Defocused Observations With Cstar

Optical Sky Brightness and Transparency during the Winter Season at Dome A Antarctica from the Gattini-All-Sky Camera

Searching for the Transit of the Earth-mass Exoplanet Proxima Centauri b in Antarctica: Preliminary Result

Contact Info

Product

Resources

About