Uncertainties in period determinations

Fernie, J. D.

doi:10.1086/132426

Cited by 105 publications

(78 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The period analysis strongly supports that presence of the period of 0.0832 ± 0.0019 d. The error of the period was estimated using the application of Lafler-Kinman class of methods by Fernie (1989). Although the error of period estimation is rather large due to the limited length of a single-night baseline, the period is 3.6σ longer than the orbital period, and is 2.1σ longer than the superhump period by Udalski (1990).…”

Section: Resultssupporting

confidence: 60%

Superhump-like variation during the anomalous state of SU UMa

Katô

2002

A&A

View full text Add to dashboard Cite

Abstract.We observed an anomalously outbursting state of SU UMa which occurred in 1992. Time-resolved photometry revealed the presence of signals with a period of 0.0832 ± 0.0019 d, which is 3.6σ longer than the orbital period (0.07635 d) of this system. We attributed this signal to superhumps, based on its deviation from the orbital period and its characteristic profile. During this anomalous state of SU UMa, normal outbursts were almost suppressed, in spite of relatively regular occurrences of superoutbursts. We consider that an ensuing tidally unstable state following the preceding superoutburst can be a viable mechanism to effectively suppress normal outbursts, resulting in an anomalously outbursting state.

show abstract

Section: Resultssupporting

confidence: 60%

Superhump-like variation during the anomalous state of SU UMa

Katô

2002

A&A

View full text Add to dashboard Cite

show abstract

“…3). Using the method described by Fernie (1989), we can estimate the true period and its uncertainty. We find P = 2.34 ± 0.03 yr for the 6 cm fluxes and P = 2.37 ± 0.03 yr for the 3.6 cm fluxes.…”

Section: Data and Radio Light Curvementioning

confidence: 99%

Non-thermal radio emission from O-type stars

Blomme¹,

Becker

Volpi

et al. 2008

A&A

View full text Add to dashboard Cite

The star Cyg OB2 No. 9 is a well-known non-thermal radio emitter. Recent theoretical work suggests that all such O-stars should be in a binary or a multiple system. However, there is no spectroscopic evidence of a binary component. Re-analysis of radio observations from the VLA of this system over 25 years has revealed that the non-thermal emission varies with a period of 2.35 ± 0.02 yr. This is interpreted as a strong suggestion of a binary system, with the non-thermal emission arising in a wind-collision region. We derived some preliminary orbital parameters for this putative binary and revised the mass-loss rate of the primary star downward from previous estimates.

show abstract

“…If any well formed, statistically significant depression was noted, the period was determined by the interpolation method of Kwee & van Woerden (1956) as promoted by Fernie (1989) for the LK statistic. It may be noted that this process provides an error estimate for the determined period.…”

Section: Tests For Time Dependence and Periodicitymentioning

confidence: 99%

On the polarimetric variability of bright O-type stars

Clarke

McDavid²,

Smith

et al. 2002

A&A

View full text Add to dashboard Cite

Abstract. Polarimetric data associated with multi-parameter observational campaigns of selected bright O-type stars and their variable winds, are analysed in relation to the outcomes of the UV and optical spectroscopic studies. For the stars ξ Per and λ Cep, individual measurement uncertainties are ∆p ∼ ±0.0002 with nightly mean uncertainties of ∆p ∼ ±0.00007. Although variability is apparent on a night-to-night basis, with differences in δp ∼ 0.0002, no correlations are found between these and the periodic behaviours associated with the stellar Si IV and Hα lines. Similar polarimetric variability is seen in the data for the standard star φ Cas used as a reference in this observing campaign. It is suggested that all of these low level fluctuations are not intrinsic to the stars but are engendered by structured instrumental polarization in the diffraction pattern and depolarization effects in combination with inconsistent target acquisition and with variable seeing conditions in the Earth's atmosphere. Reassessment of older data for λ Cep from Hayes (1978) also supports this thesis.

show abstract

Uncertainties in period determinations

Cited by 105 publications

References 1 publication

Superhump-like variation during the anomalous state of SU UMa

Superhump-like variation during the anomalous state of SU UMa

Non-thermal radio emission from O-type stars

On the polarimetric variability of bright O-type stars

Contact Info

Product

Resources

About