Chromospheric telescope of Baikal Astrophysical Observatory. New light

2016 ◽  
Vol 2 (2) ◽  
pp. 69-85 ◽  
Author(s):  
Валерий Скоморовский ◽  
Valery Skomorovsky ◽  
Галина Кушталь ◽  
Galina Kushtal ◽  
Любовь Лоптева ◽  
...  
Keyword(s):  
Ccd Camera ◽  
Spectral Parameters ◽  
Optical Elements ◽  
Wavefront Distortion ◽  
Solar Research ◽  
Telescope Optics ◽  
Synoptic Observations ◽  
First Time ◽  
Iceland Spar ◽  
Optical Immersion

A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a detector 36×24 mm (4000×2672 pixels) was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and a new Iceland spar and quartz crystal plates instead of damaged ones were made and installed in the Hα birefringent filter (BF), manufactured by Bernhard Hallе Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and pre-filter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the Ha line core and wing.

scholarly journals Chromospheric telescope of Baikal Astrophysical Observatory. New light

2016 ◽  
Vol 2 (2) ◽  
pp. 82-103
Author(s):  
Валерий Скоморовский ◽  
Valery Skomorovsky ◽  
Галина Кушталь ◽  
Galina Kushtal ◽  
Любовь Лоптева ◽  
...  
Keyword(s):  
Ccd Camera ◽  
Spectral Parameters ◽  
Optical Elements ◽  
Wavefront Distortion ◽  
Solar Research ◽  
Telescope Optics ◽  
Synoptic Observations ◽  
First Time ◽  
Optical Immersion ◽  
Full Disk

A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at the Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a 36×24 mm detector (4000×2672 pixels) was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and new calcite and quartz crystal plates were made and installed instead of damaged ones in the Hα birefringent filter (BF), manufactured by Bernhard Hallе Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and prefilter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the Hα line core and wing.

scholarly journals Polarization calibration techniques and scheduling for the Daniel K. Inouye Solar Telescope

2014 ◽  
Vol 10 (S305) ◽  
pp. 102-107
Author(s):  
David F. Elmore
Keyword(s):  
Advanced Technology ◽  
Optical Coatings ◽  
Calibration Error ◽  
Solar Telescope ◽  
Critical Importance ◽  
Common Path ◽  
Solar Research ◽  
Telescope Optics ◽  
The Individual ◽  
Calibration Techniques

AbstractThe Daniel K. Inouye Solar Telescope (DKIST), formerly Advanced Technology Solar Telescope when it begins operation in 2019 will be by a significant margin Earth's largest solar research telescope. Science priorities dictate an initial suite of instruments that includes four spectro-polarimeters. Accurate polarization calibration of the individual instruments and of the telescope optics shared by those instruments is of critical importance. The telescope and instruments have been examined end-to-end for sources of polarization calibration error, allowable contributions from each of the sources quantified, and techniques identified for calibrating each of the contributors. Efficient use of telescope observing time leads to a requirement of sharing polarization calibrations of common path telescope components among the spectro-polarimeters and for those calibrations to be repeated only as often as dictated by degradation of optical coatings and instrument reconfigurations. As a consequence the polarization calibration of the DKIST is a facility function that requires facility wide techniques.

scholarly journals Visible AO Observations at Halpha for Accreting Young Planets

2013 ◽  
Vol 8 (S299) ◽  
pp. 32-33
Author(s):  
L.M. Close ◽  
K. Follette ◽  
J.R. Males ◽  
K. Morzinski ◽  
T.J. Rodigas ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Binary Stars ◽  
Optical Resolution ◽  
Ccd Camera ◽  
Short Exposure ◽  
Low Mass ◽  
Orion Trapezium ◽  
First Time ◽  
Adaptive Optics System ◽  
Very High

AbstractWe utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high-resolution science in the visible with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.5–0.7″) we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60s) r' (0.63μm) images are slightly coarser at FWHM = 23-29 mas (Strehl ~ 28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young (~ 1 Myr) Orion Trapezium θ1 Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary θ1 Ori C1C2 was easily resolved in non-interferometric images for the first time. Relative positions of the bright trapezium binary stars were measured with ~ 0.6–5 mas accuracy. In the second commissioning run we were able to correct 378 modes and achieved good contrasts (Strehl>20% on young transition disks at Hα). We discuss the contrasts achieved at Hα and the possibility of detecting low mass (~ 1–5 Mjup) planets (past 5AU) with our new SAPPHIRES survey with MagAO at Hα.

scholarly journals Phase-Shift Optimization in AA/PVA Photopolymers by High-Frequency Pulsed Laser

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1887
Author(s):  
Daniel Puerto ◽  
Sergi Gallego ◽  
Jorge Francés ◽  
Andrés Márquez ◽  
Inmaculada Pascual ◽  
...  
Keyword(s):  
Phase Shift ◽  
High Frequency ◽  
Large Scale ◽  
Pulsed Laser ◽  
Laser Exposure ◽  
Continuous Laser ◽  
Frequency Limit ◽  
Optical Elements ◽  
First Time ◽  
532 Nm

Photopolymers can be used to fabricate different holographic optical elements, although maximization of the phase-shift in photopolymers has been a challenge for the last few decades. Different material compositions and irradiation conditions have been studied in order to achieve it. One of the main conclusions has been that with continuous laser exposure better results are achieved. However, our results show for the first time that higher phase-shift can be achieved using a pulsed laser. The study has been conducted with crosslinked acrylamide-based photopolymers exposed with a pulsed laser (532 nm). The increment of the phase-shift between the pulsed laser and continuous laser exposure is 17%, achieving a maximum phase-shift of 3π radians and a refractive index shift of 0.0084 at the zero spatial frequency limit, where monomer diffusion does not take place. This allows this photopolymer to be used in large-scale manufacturing.

scholarly journals Boxy Isophotes and Dust Lanes in Bright Virgo Ellipticals

1987 ◽  
Vol 127 ◽  
pp. 409-410
Author(s):  
C. Möllenhoff ◽  
R. Bender
Keyword(s):  
Color Index ◽  
Ccd Camera ◽  
Major Axis ◽  
Elliptical Galaxies ◽  
Virgo Cluster ◽  
Least Square ◽  
Semi Major Axis ◽  
Morphological Studies ◽  
Main Indicator ◽  
First Time

The CCD camera of the Landessternwarte Heidelberg was used at the 1.2 m Calar Alto Telescope for a V, R, I - survey of ~70 dusty and non-dusty elliptical galaxies. We report here about morphological studies of ten bright elliptical galacxies in the Virgo cluster. After the usual CCD data reduction the following procedures were carried through:1. The CCD-frames were filtered and centered to an accuracy of ~ 0. 2 pixels. By division we obtained V-R, V-I, R-I color index images which allow to separate dust absorption and gaseous emission from the stellar distribution. Five of the 1 0 bright Virgo ellipticals evidently show dust/gas, two other objects have weak features. The dust lanes in NGC k26 (cf. Fig. l), NGC 4365 and NGC 4552 were detected for the first time. A dust lane must be visible in all three color index frames in order to avoid fake identifications.2. The isophotes in all three colors were fitted by least square ellipses. From these fits we obtained in dependence from the radius: color profiles, color index profiles, ellipticity profiles, isophote twists (cf. Fig. 2). The deviations of the isophotes from ideal ellipses were studied by a Fourier series analysis. The fourth coefficient is the main indicator for such deviations. Six of ten galaxies show box-shaped isophotes of an amount between 0. 3 % and 1. 5 % of the semi major axis (cf. Fig. 3) 5 two galaxies show disc components (0. 8 1.5 %), only one galaxy is a perfect elliptical up to an error of ±0.2 %. The deviations are equal in all three colors and therefore are not produced by dust.

scholarly journals Solar observations at the Coimbra Astronomical Observatory

2019 ◽  
Vol 28 (1) ◽  
pp. 165-179 ◽  
Author(s):  
Ana Lourenço ◽  
Sara Carvalho ◽  
Teresa Barata ◽  
Adriana Garcia ◽  
Víctor Carrasco ◽  
...  
Keyword(s):  
Ccd Camera ◽  
Astronomical Observatory ◽  
Photographic Emulsion ◽  
Digital Recording ◽  
Solar Observations ◽  
Synoptic Observations ◽  
Data Collections ◽  
The University ◽  
Near Future

Abstract In 2020, the Geophysical and Astronomical Observatory of the University of Coimbra will celebrate the 95th anniversary of its first spectroheliographic observation. Keeping a daily service of solar observations since then, making almost a century, led to one of the largest continuous solar data collections in the world. This long–term solar database is essential for studies where solar activity is involved. This work reviews the development of synoptic observations made at the Observatory of Coimbra since 1925 and presents a summary of some of the principal stages of the Observatory’s history since its founding in 1772. We refer the main technical improvements and present some perspectives for the near future. One of the most significant upgrades was the installation of a CCD camera in 2007. The transition from photographic emulsion to digital recording methods allowed the development of image analysis algorithms to process solar images and improved data sharing with other institutions. This upgrade enabled also to carry–out modern climate and space weather studies. This valuable advancement makes it possible to create a new catalogue of solar observations to be published in the future.

scholarly journals Nachweis der Atropisomerie peri-substituierter Naphthalin-Derivate durch dynamische 1H-NMR-Spektroskopie / Dynamic 1H-NMR-Spectroscopic Evidence for the Atropisomerism of Perisubstituted Naphthalene Derivatives

1977 ◽  
Vol 32 (8) ◽  
pp. 912-933 ◽  
Author(s):  
Reiner Luckenbach ◽  
Axel Jensen
Keyword(s):  
1H Nmr ◽  
Chiral Molecules ◽  
Kcal Mole ◽  
Naphthalene Derivatives ◽  
Spectral Parameters ◽  
Hindered Rotation ◽  
H Nmr ◽  
Environment Temperature ◽  
Dynamic 1H Nmr ◽  
First Time

The preparation of the perisubstituted naphthalene derivatives 1-8 is described for the first time, and possible axial or axial and planar chirality of these compounds is investigated by means of dynamic 1H NMR spectroscopy. Molecular chirality, caused by hindered rotation, can be proven for compounds 1 and 3 at room temperature and for 2 at 193 K by the observation of magnetic inequivalence of isochronous protons in a diastereotopic environment. Temperature-dependent 1H NMR spectra indicate that for 2 the coalescence temperature lies between 193 K and 213 K, and above 320 K for 3. By assuming Tcoal- = 200 K for 2 and Tcoal. > 320 K for 3 the following ⊿G≠-values were estimated with the aid of known approximations from the 1H NMR spectral parameters Δν = νA-νB and JAB for the methylene and methyl groups of the oxazoline system present in these species: ⊿G≠ (2) = 10.1 kcal/mole (at 200 K), ⊿G≠ (3) = 17.3 (16.2) kcal/mole (at 320 K). These ⊿G≠-values represent the energy barriers of a dynamic intramolecular process, presumably according to a more or less hindered rotation in the purely axially chiral molecules 2 and 3. With the aid of these ⊿G≠-values and model considerations a description of the energy profile diagram of the hindered rotation in compounds 2 and 8 is attempted.

scholarly journals A New Method for a Side-Scattering Lidar to Retrieve the Aerosol Backscattering Coefficient

2020 ◽  
Vol 237 ◽  
pp. 08001
Author(s):  
Zhenzhu Wang ◽  
Zongming Tao ◽  
Dong Liu ◽  
Chenbo Xie ◽  
Yingjian Wang
Keyword(s):  
Numerical Simulation ◽  
Case Studies ◽  
Ccd Camera ◽  
New Method ◽  
Inversion Method ◽  
Backscattering Coefficient ◽  
First Time

The side-scattering lidar based on the CCD camera is a powerful tool to measure the near- ground aerosol, which is most interesting for the environmental and meteorological departments. The inversion method for the side-scattering lidar is different from the conventional Fernald method due to the differences in two lidar equations. A new inversion method for the side-scattering lidar to retrieve the aerosol backscattering coefficient is proposed for the first time, which is based on the aerosol backscattering coefficient at the ground as a restriction condition. Numerical simulation is used to analyze the convergence of this new method. Case studies indicate that this new method is reasonable and feasible.REFERENCES

Spatio-temporally Resolved Investigation of Surface Charges, N2(A3∑u+) Metastables and Discharge Development in Barrier Discharges

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Marc Bogaczyk ◽  
Sebastian Nemschokmichal ◽  
Anton Zagoskin ◽  
Goran B. Sretenović ◽  
Jürgen Meichsner ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Ccd Camera ◽  
Diagnostic Techniques ◽  
Correlation Spectroscopy ◽  
Pockels Effect ◽  
Surface Charges ◽  
Discharge Cell ◽  
Barrier Discharges ◽  
First Time

AbstractTo study the interaction of an insulated surface with the volume of a barrier discharge, a discharge cell was developed to combine for the first time three diagnostic techniques in ONE discharge cell configuration. The discharge development was investigated by the cross-correlation-spectroscopy (CCS), the surface charge measurement on the dielectrics by the application of the optoelectronic Pockels effect in combination with a CCD camera, and the determination of the metastable N

ALTERATIONS IN AUTOFLUORESCENCE SIGNAL FROM RAT SKIN EX VIVO UNDER OPTICAL IMMERSION CLEARING

2010 ◽  
Vol 03 (03) ◽  
pp. 147-152 ◽  
Author(s):  
E. V. MIGACHEVA ◽  
A. B. PRAVDIN ◽  
V. V. TUCHIN
Keyword(s):  
Fluorescence Spectroscopy ◽  
Ex Vivo ◽  
Rat Skin ◽  
Optical Clearing ◽  
Spectral Curves ◽  
The Common ◽  
First Time ◽  
Tissue Optical Clearing ◽  
Optical Immersion

For the first time, the changes in autofluorescence spectra of ex vivo rat skin have been experimentally investigated using the combination of fluorescence spectroscopy and optical immersion clearing. The glucose, glycerol and propylene glycol solutions were used as clearing agents. The optical clearing was performed from the dermal side of skin imitating the in vivo injection of clearing agent under the dermal layers. In this contribution, the common properties of autofluorescence variation during optical immersion clearing were determined. The tendency of autofluorescence signal to decrease with reduction of scattering in tissue was noticed and discussed in detail. However, the differences in the shape of spectral curves under application of different clearing agents showed that optical clearing affects the autofluorescence properties of tissue differently depending on the type of clearing liquid. The results obtained are useful for the understanding of tissue optical clearing mechanisms and for improving techniques such as fluorescence spectroscopy.

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