Polarimetry, photometry, and spectroscopy of comet C/2009 P1 (Garradd)

Ivanova, Oleksandra; Rosenbush, V. K.; Afanasiev, V. L.; Kiselev, N. N.

doi:10.1016/j.icarus.2016.11.014

Cited by 18 publications

(8 citation statements)

References 51 publications

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“…The correction for the zero point of instrumental position angle ΔPA was found from observations of standard stars with large interstellar polarization (Hsu and Breger, 1982). The image processing, reduction, errors estimation, and the method of calculation of polarization parameters with SCORPIO-2 are described in more details by Afanasiev and Amirkhanyan (2012), Afanasiev et al (2014), Ivanova et al (2015, 2017a, 2017b), and Rosenbush et al (2017.…”

Section: The Observed Polarization Profilesmentioning

confidence: 99%

Comet 2P/Encke in apparition of 2017: II. Polarization and color

Kiselev

Rosenbush

Ivanova

et al. 2020

Icarus

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Section: The Observed Polarization Profilesmentioning

confidence: 99%

Comet 2P/Encke in apparition of 2017: II. Polarization and color

Kiselev

Rosenbush

Ivanova

et al. 2020

Icarus

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“…Typically the instrumental polarization was less than 0.1%. A detailed description of the data reduction and the method of the calculation of polarization parameters with SCORPIO-2 can be found in Afanasiev & Amirkhanyan (2012), Afanasiev et al (2014), Ivanova et al (2009, 2017a), and Rosenbush et al (2017. The errors in the averaged polarization degree varied from 0.12% in the near-nucleus region to 1.1% in the tail at projected distance ρ from the coma photocenter ∼150 000 km.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

“…To exclude spurious features when interpreting the obtained images, each of the digital filters was applied with the same processing parameters for all individual exposures. This technique was used before to pick out structures in several comets with good results (Ivanova et al 2009(Ivanova et al , 2016(Ivanova et al , 2017a(Ivanova et al , 2018Rosenbush et al 2017;Picazzio et al 2019).…”

Section: Morphologymentioning

confidence: 99%

Photometry, spectroscopy, and polarimetry of distant comet C/2014 A4 (SONEAR)

Ivanova

Lukyanyk

Kolokolova

et al. 2019

A&A

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Context. The study of distant comets, which are active at large heliocentric distances, is important for better understanding of their physical properties and mechanisms of long-lasting activity. Aims. We analyze the dust environment of the distant comet C/2014 A4 (SONEAR), with a perihelion distance near 4.1 au, using comprehensive observations obtained by different methods. Methods. We present an analysis of spectroscopy, photometry, and polarimetry of comet C/2014 A4 (SONEAR), which were performed on November 5 -7, 2015, when its heliocentric distance was 4.2 au and phase angle was 4.7 • . Long-slit spectra and photometric and linear polarimetric images were obtained using the focal reducer SCORPIO-2 attached to the prime focus of the 6-m telescope BTA (SAO RAS, Russia). We simulated the behavior of color and polarization in the coma presenting the cometary dust as a set of polydisperse polyshapes rough spheroids. Results. No emissions were detected in the 3800 -7200 Å wavelength range. The continuum showed a reddening effect with the normalized gradient of reflectivity 21.6±0.2% per 1000 Å within the 4650 -6200 Å wavelength region. The fan-like structure in the sunward hemisphere was detected. The radial profiles of surface brightness differ for r-sdss and g-sdss filters, indicating predominance of submicron and micron-sized particles in cometary coma. The dust color (g-r) varies from 0.75±0.05 m to 0.45±0.06 m along the tail. For aperture radius near 20 000 km, the dust productions in various filters were estimated as A f ρ = 680±18 cm (r-sdss) and 887±16 cm (g-sdss). The polarization map showed spatial variations of polarization over the coma from about -3% near the nucleus to -8% at cometocentric distance about 150 000 km. Our simulations show that the dust particles were dominated (or covered) by ice and tholin-like organics. Spatial changes in the color and polarization can be explained by particle fragmentation.

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“…A detailed description of the procedure used to process polarimetric images is given in Refs. [9,22]. Table 1 provides the following information: the date of an observation (the mid-cycle time); the respective heliocentric, r, and geocentric, Δ, distances; the phase angle α; the spectral filter and its effective wavelength λ eff ; the total exposure time T exp ; the degree of linear polarization P; and the name of the comet.…”

Section: Results Of Polarimetric Observationsmentioning

confidence: 99%