Related papers: Photometry differential of comets
An analysis is presented for the photometric data on comet C/2013 A1 (Siding Spring) from observations at a large heliocentric distance (near 4.1 AU). Comet C/2013 A1 (Siding Spring) displays intense activity despite the relatively large…
The Chinese Small Telescope ARray (CSTAR) carried out high-cadence time-series observations of 27 square degrees centered on the South Celestial Pole during the Antarctic winter seasons of 2008, 2009 and 2010. Aperture photometry of the…
(Abridged) In the first part of this thesis, a general methodology for applying image deconvolution to wide-field CCD imagery. Results show that wavelet-based deconvolution can increase limiting magnitude up to 0.6 mag and improve limiting…
The measurement of type Ia supernovae magnitudes provides cosmological distances, which can be used to constrain dark energy parameters. Large photometric surveys require a substantial improvement in the calibration precision of their…
We present the optical imaging polarimetric observations of comet C/2009 P1(Garradd) at three different phase angles e.g., 28.2$^\circ$, 28.1$^\circ$ and 21.6$^\circ$. The observations were carried out using IUCAA Faint Object Spectrograph…
We present the results from a three night, time-series study of the open cluster NGC 6791 using the Megacam wide-field mosaic CCD camera on the 6.5m MMT telescope. The aim of this study was to demonstrate the ability to obtain very high…
We have obtained imaging polarimetry of the comet C/2013 R1 (Lovejoy) with 2-Channel-Focal-Reducer Rozhen instrument at 2m Ritchey-Chr\'etien-Coud\'e telescope of the Bulgarian National Astronomical Observatory Rozhen in two dust continuum…
We report on submillimetre observations of three high redshift (z>6) quasars, made using the SCUBA camera on the JCMT. Only one of the sample was detected at 850um-- SDSS J1148+5251 (z=6.43). It was also detected (>3 sigma significance) at…
The precise measurements of the Compton scatterings of photons originating from the decay of positronium atoms can reveal information about their polarizations. J-PET detector is constructed of 192 plastic scintillators and is unique to…
A complete set of linearly independent observables in Compton scattering with arbitrarily polarised real photons off an arbitrarily polarised spin-1 target is introduced, for the case that the final-state polarisations are not measured.…
A critical analysis and comparison of different methods for obtaining point spread function (PSF) photometry are carried out. Deep ACS observations of NGC3370 were reduced using four distinct approaches. These reductions explore a number of…
We present calibrated ATLAS photometry of the interstellar comet 3I/ATLAS (C/2025 N1) from 28 March through 29 Aug 2025, obtained with the five-site, robotic ATLAS network in the c (420-650~nm), o (560-820~nm), and Teide w (420-720~nm)…
We provide a new gravity field of Comet 67P-C/G up to degree 4. We detect mass heterogeneity in the comet nucleus. The loss of mass is restimated at 0.28\% of the comet's total mass (3 times larger than previous estimate). Comparison of the…
We consider a method for obtaining information on polarization of astronomical objects radiation at diffraction limited resolution - differential speckle polarimetry. As an observable we propose to use averaged cross spectrum of two…
The Rosetta spacecraft accompanied the comet 67P/C-G for nearly 2 years, collecting valuable data on the neutral and ion composition of the coma. The Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ plasma…
We present an analysis of long-slit cometary spectroscopy using the dual-arm ISIS spectrograph on the 4.2 m WHT. Eleven comets were observed over two nights in 2016 March and we detected the OH (0-0) emission band at 3085 {\AA} in the…
We present mid-infrared spectra and images from the GEMINI-N (+Michelle) observations of fragments SW3-[B] and SW3-[C] of the ecliptic (Jupiter Family) comet 73P/Schwassmann-Wachmann 3 pre-perihelion. We observed fragment B soon after an…
ASTEP South is the first phase of the ASTEP project (Antarctic Search for Transiting ExoPlanets). The instrument is a fixed 10 cm refractor with a 4kx4k CCD camera in a thermalized box, pointing continuously a 3.88 degree x 3.88 degree…
New BVRI light curves of the eclipsing binary system 1SWASP J160156.04+202821.6 have been obtained with the 1.88-m telescope of Kottamia Astronomical Observatory (KAO), Egypt on June, 2013. New twenty times of minima of the system J1601 and…
On 3 and 4 October, 1995, we obtained high spectral resolving power (R=\lambda/\Delta\lambda = 60,000) observations of comet 122P/de Vico using the 2DCoude cross-dispersed echelle spectrograph on the 2.7-m telescope of McDonald Observatory.…