CCD astrolabe solar diameter measurements in 1999–2000

Penna, J. L.; Jilinski, E. G.; Andrei, A. H.; Puliaev, S. P.; Neto, E. Reis

doi:10.1051/0004-6361:20020065

Cited by 16 publications

(15 citation statements)

References 11 publications

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“…2 we plot the daily mean values of the solar radius obtained with the CCD astrolabe of Rio de Janeiro during the period 1997-2000. These results can be obtained in electronic form at CDS and according to Penna et al (2002) they "... supersede all others based on preliminary data from this program." Therefore, the data of Rio de Janeiro that we shall discuss here are definitive.…”

Section: Solar Radius Measurements At Rio De Janeiro 1997-2000mentioning

confidence: 53%

“…4). Concerning the CCD astrolabe of Rio de Janeiro, its results for 1997-2000 are now available at CDS (Jilinski et al 1999;Puliaev et al 2000;Penna et al 2002). It is true that for this period the drift of the radius mesurements of this astrolabe is similar to the results of Laclare.…”

Section: Solar Radius Variations Observed At Cerga and Santiagomentioning

confidence: 69%

“…However, modifications introduced after our discussion in the results of the CCD astrolabe of Rio de Janeiro (Penna 2002) and the publication of the latest results of this astrolabe (Penna et al 2002), provide new and quite interesting information for the problem of solar radius variations and give additional evidence that the apparent radius of the Sun varies in phase with solar magnetic activity.…”

Section: Solar Radius Measurements At Rio De Janeiro 1997-2000mentioning

confidence: 94%

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On solar radius measurements with Danjon astrolabes

Noel

2002

A&A

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Abstract. During the last 25 years the Danjon astrolabe has been used extensively for measuring the apparent solar diameter. Here we discuss some aspects of the results obtained with the CCD astrolabes of Antalya (Turkey) and Rio de Janeiro (Brazil), and with the visual astrolabes of CERGA (France) and Santiago (Chile). The most extended databases obtained with these astrolabes are those of CERGA and probably Santiago. However, concerning observed variations in time of the solar radius, the results of both stations are discrepant. While the CERGA results show a marginal radius variation in opposing phase with solar magnetic activity, those of Santiago give a significant variation in time, but in phase with solar activity. According to Chollet & Sinceac (1999) the apparent solar radius variation is identical for all astrolabe measures (except Santiago) and anticorrelated with the magnetic cycle of the Sun. However, we show here that according to published results, the astrolabes of Antalya and Santiago give similar radius variation. With respect to the results of Rio de Janeiro, they show strong internal inconsitencies due probably to instrumental modifications made during its observational campaign. After removing these inconsistencies, the results of Rio de Janeiro become almost identical to those of Santiago. The results of these astrolabes, Antalya, Rio de Janeiro and Santiago, are in agreement with recent results obtained with different observational techniques, which show also that the apparent solar radius would vary in phase with solar magnetic activity.

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Section: Solar Radius Measurements At Rio De Janeiro 1997-2000mentioning

confidence: 53%

Section: Solar Radius Variations Observed At Cerga and Santiagomentioning

confidence: 69%

Section: Solar Radius Measurements At Rio De Janeiro 1997-2000mentioning

confidence: 94%

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On solar radius measurements with Danjon astrolabes

Noel

2002

A&A

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“…For example, the most recent observations (Penna et al 2002) show that the solar radius can be measured with the precision of 0.18 arcsec using CCD Astrolabe. Imagining the huge geometric size of the solar surface, we think the measurement with so good precision must have its measurable base.…”

Section: Introductionmentioning

confidence: 99%

Image-processing techniques in precisely measuring positions of Jupiter and its Galilean satellites

Peng

Han

Zhang

et al. 2003

A&A

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Abstract. Two image-processing techniques are developed to measure precisely the positions of Jupiter and its Galilean satellites. One is used to detect the edge of Jupiter's CCD image and fit it with an ellipse, thereby obtaining the planetary center. The other is used to remove the positional effect of Jupiter's scattering light that has on the measurement of a close satellite. 133 frames of CCD images are measured by using these techniques, and these measured positions of Galilean satellites are compared to the ones computed with the ephemerides of Jacobson's JUP204 and Arlot's G5. Preliminary analysis of the data as Jupiter-satellite or inter-satellite positions shows that a standard error (i.e. internal precision) as small as 0.03 arcsec can be reached in right ascension and declination. It is believed that these techniques would be useful for astrometric and photometric CCD observations of Galilean satellites, especially for CCD observations in the forthcoming mutual phenomena of Galilean satellites.

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“…One of these widely used instruments is the solar astrolabe. The description of the visual and CCD generation of this instrument and the results obtained for the diameter of the Sun are given by Laclare et al (1991Laclare et al ( , 1996Laclare et al ( , 1999, Delmas et al (2006), Andrei et al (2004), Gölbaşi et al (2000Gölbaşi et al ( , 2001, Jilinski et al (1999), Penna et al (2002), and Kilic et al (2005).…”

Section: Introductionmentioning

confidence: 99%

Processing Method Effect on Sun Diameter Measurement With CCD Solar Astrolabe

Djafer

Irbah

2012

ApJ

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Photometric Sun diameter measurement is based on the calculation of the inflection point of the solar limb. In ground measurement, this point is located at a position on the solar limb where the signal-to-noise ratio is very high, which necessitates the appropriate filtering techniques to eliminate the noise while preserving its position. In this paper, we compare the filtering method currently in use to process the CCD solar astrolabe data, the FFTD method widely used, with a different method that we propose. Using the acquired data from the CCD astrolabe at Calern, France during 1997, we can obtain a mean difference of 130 mas in the measured radii.

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CCD astrolabe solar diameter measurements in 1999–2000

Cited by 16 publications

References 11 publications

On solar radius measurements with Danjon astrolabes

On solar radius measurements with Danjon astrolabes

Image-processing techniques in precisely measuring positions of Jupiter and its Galilean satellites

Processing Method Effect on Sun Diameter Measurement With CCD Solar Astrolabe

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