Abstract: In this report, we present an overview of the 3rd BINA workshop hosted by ARIES, Nainital on a broad theme the Scientific potential of the Indo-Belgian co-operation. Further, an introduction of the proceedings of the 3rd BINA workshop is also delineated along with possible areas where there is potential to extend Indo-Belgian cooperation in the current era of multi-wavelength astronomy. These proceedings contain a total of 94 articles that are based on results presented in the form of 35 oral and 59 poster presentations during the workshop. The participants of the workshop strongly recommend the further continuation of the BINA activities since the necessary foundation work has already been accomplished. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: The article describes the approach followed by the Devasthal Time Allocation Committee to evaluate observing proposals to the Devasthal Optical Telescope (DOT) over the period 2020–2023, the results of the time allocation process, and some statistics of the proposals and final time allocation. It also provides some suggestions to the Aryabhatta Research Institute of Observational Sciences that aim to improve the DOT science output and the quality of observing proposals, as well as suggestions to DOT proposers to help improve their chances of obtaining DOT observing time in the future. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: The adaptive optics (AO) technology is crucial to achieve the full potential of ground-based telescopes. Over the last three decades, the world has witnessed the successful advent and operation of AO systems on large ground-based telescopes. The complexity and cost of AO systems have largely gone down in the last decade thanks to advances in deformable mirror, wavefront sensor, and real-time computing technologies. Here, we present a robust Rayleigh scattered laser-guided single conjugated adaptive optics system called SALTO, which was designed, built, and tested in the Belgian countryside on a 1-meter class telescope. This project aims to demonstrate the possibility of rejuvenating the scientific goals of medium-class telescopes (1-3 m) with AO technology, as well as to enable optical telecommunication from relatively poor observing sites. This paper discusses the overview of the design, integration and calibration of SALTO. It concludes with the presentation of successful on-sky results at 1.55 μm under 2-3" seeing. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: The Indo-Belgian bilateral project titled “Belgo-Indian Network for Astronomy and Astrophysics (BINA)” is an excellent initiative to spark scientific collaboration between Belgian and Indian astronomers. The Belgian university, KU Leuven, owns and operates the semi-robotic Mercator telescope - a 1.2m telescope stationed at the Roque de los Muchachos observatory on the island of La Palma. This telescope is equipped with the High-Efficiency and high-Resolution Mercator Echelle Spectrograph (HERMES). This contribution aims to discuss a long-standing idea - what would BINA, and by extension the entire Indian astronomical community, gain with the addition of a similar 1-m class telescope with a high-resolution spectrograph in Devasthal. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: We present here the information on the design and performance of the recently commissioned 2.5-meter telescope at the PRL Mount Abu Observatory, located at Gurushikhar, Mount Abu, India. The telescope has been successfully installed at the site, and the Site Acceptance Test (SAT) was completed in October 2022. It is a highly advanced telescope in India, featuring the Ritchey-Chrétien optical configuration with primary mirror active optics, tip-tilt on sideport, and wave front correction sensors. Along with the telescope, its two first light instruments namely Faint Object Camera (FOC) and PARAS-2 were also integrated and attached with it in the June 2022. FOC is a camera that uses a 4096 X 4112 pixels detector SDSS type filters with enhanced transmission and known as u’, g’, r’, i’, z’. It has a limiting magnitude of 21 mag for 10 minutes exposure in the r’-band. The other first light instrument, PARAS-2, is a state-of-the-art high-resolution fiber-fed spectrograph operating in the 380-690 nm wave-band, aimed to unveil the super-Earth like worlds. The spectrograph works at a resolution of ∼107,000, making it the highest-resolution spectrograph in Asia to date, It is employed in an ultra-stable temperature and pressure environment, at 22.5 ± 0.001 ◦C and 0.005 ± 0.0005 mbar, respectively. Initial calibration tests of the spectrograph using a Uranium Argon Hollow Cathode Lamp (UAr HCL) have yielded intrinsic instrumental RV stability down to 30 cm s−1. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: This project is focused on evaluating the slowly-varying ground layer seeing component at the optical telescopes of ARIES. To achieve this, we assembled the instrument, consisting of a filter wheel, a CCD camera, and a tip-tilt enabled transparent glass plate integrated within an off-the-shelf unit termed as the AO (Adaptive Optics) unit. The instrument developed by us was deployed on the 1.04-m f/13 Sampurnanand telescope at Manora Peak and the 1.3-m f/4 telescope at Devasthal. This instrument measures the average instantaneous slope (tip/tilt) of the incoming wavefront over the telescope aperture via a fast (within the atmospheric coherence time) sampled image and corrects it via a software-controlled oscillating (tipping/tilting) single thin glass plate. The night observations revealed that the slowly-varying seeing component is significant at both observatories and can be effectively controlled to enhance the sharpness of the celestial images at the two sites. The most significant improvement was measured from 5 arcsec of uncorrected FWHM of a star to 3.4 arcsec of corrected FWHM in the 1.04-m telescope in the evening hours. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: National Astronomical Research Institute of Thailand (NARIT) has a manifold network of small telescopes installed worldwide. These telescopes serve educational and research purposes and are equipped mainly with CCD detectors for direct imaging and photometry. To extend the possible field of applications, several telescopes were fitted with commercially available medium resolution spectrographs eShel from Shelyak. With these devices, researchers in NARIT obtained a versatile tool for stellar spectroscopy. Here we describe the current status of available equipment, possible ways of upgrading, and briefly introduce the achieved results of the asteroseismologic study of fast-rotating stars. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: Comets are pristine remnants of the Solar system, composed of dust and ice. They remain inactive and undetectable for most of their orbit due to low temperatures. However, as they approach the Sun, volatile materials sublimate, expelling dust and creating a visible coma. Spectroscopic observations of comets help the simultaneous study of both the gas emissions and reflected sunlight from dust particles. By implementing a long slit, the spatial variations in molecular emissions can be analysed to be further used for other computations. Additionally, spatial information aids in extracting the characteristic profile of the Afρ parameter, revealing insights into the behaviour of dust emissions. A sufficiently long slit would prove advantageous in extracting information about the emissions occurring at different parts of the coma or even the tail. We can gain an overall comprehensive understanding of a comet’s chemical composition and dust emission by constructively utilising low-resolution spectroscopy with the help of a long slit. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: We present a study of three highly non-radial solar wind events in which the azimuthal solar wind flow angle exceeds 6° for one day or more. None of the events are associated with coronal mass ejections and co-rotating interaction regions observed at 1 AU. For all events, the solar wind outflows at 1 AU exhibit low velocity and density. Based on the significant increase in the oxygen charge state ratio of O7+/O6+ at 1 AU for all of the events, we have traced them back to the Sun and found that their source regions originated in active region and coronal hole (AR-CH) pairs mainly located at the central meridian. Furthermore, examining the dynamical evolutions in their source regions using both the Extreme ultra-violet Imaging Telescope and the Michelson Doppler Imager, we found that the changes taking place in AR-CH boundaries eventually disturbed the stable CH configurations, resulting in a reduction of the CH area and finally its disappearance, leaving only with the AR. Our study provides a possible explanation for discussing the origin of the prolonged and highly non-radial solar wind flows. PubDate: Tue, 11 Jun 2024 00:00:00 +020
Abstract: When stars depart from the main-sequence, various changes occur including the loss of angular momentum owing to changes in the stellar interior and the impact of stellar winds. These processes affect the amount of outer atmospheric heating and emission as revealed by observations in the UV and X-ray spectral regimes. From a theoretical perspective, both magnetic and acoustic energy generation are affected as indicated by detailed theoretical simulations. Here, I will summarize selected observational and theoretical results, including recent work for β Hydri (G2 IV), a star constituting a prime example and proxy for the future Sun. PubDate: Tue, 11 Jun 2024 00:00:00 +020
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