TCP J18224935-2408280: a symbiotic star identified during outburst

TCP J18224935-2408280 was reported to be in outburst on 2021 May 19. Follow-up spectroscopic observations confirmed that the system was a symbiotic star. We present optical spectra obtained from the Himalayan Chandra Telescope during 2021-22. The early spectra were dominated by Balmer lines, He I lines and high ionization lines such as He II. In the later observations, Raman scattered O VI was also identified. Outburst in the system started as a disc instability, and later the signature of enhanced shell burning and expansion of photospheric radius of the white dwarf was identified. Hence we suggest this outburst is of combination nova type. The post-outburst temperature of the hot component remains above 1.5 x 10$^5$ K indicating a stable shell burning in the system for a prolonged time after the outburst. Based on our analysis of archival multiband photometric data, we find that the system contains a cool giant of M1-2 III spectral type with a temperature of $\sim$ 3600K and a radius of $\sim$ 69 R$_\odot$. The pre- and post-outburst light curve shows a periodicity of 631.25 $\pm$ 2.93 d; we consider this as the orbital period.Comment: 10 pages, 12 figures, 3 table; published in MNRA

Optical studies of novae

We review the observational characteristics of classical and recurrent novae in the optical region, in the context of observational programmes carried out using telescopes at the Vainu Bappu Observatory (VBO) and the Indian Astronomical Observatory (IAO) of the Indian Institute of Astrophysics. The article discusses the different classes of novae, based on either their outburst light curve properties, or their spectral development. Also provided is a brief discussion on the quiescence properties of novae

Near-Infrared and Optical Studies of the fast nova V4643 Sgr (Nova Sagittarii 2001)

V4643 Sagittarii or Nova Sagittarii 2001 was discovered in outburst at 7.7 mag. on 2001 February 24. Here, we present near-infrared results of this fast classical nova obtained in the early decline phase in 2001 March followed by optical observations about one month later. Subsequently we also present near-infrared spectra taken later in the nova's evolution, about four months after the outburst, when V4643 Sgr had entered the coronal phase. The spectra in the early decline phase are dominated by emission lines of the HI Brackett series and also the Paschen beta and gamma lines. We study the cause of the excitation of the the OI line at 1.128 micron and discuss the variation in its strength with time after outburst. We discuss the role of optical depth effects on the observed strengths of the hydrogen Brackett and Paschen lines and discuss possible reasons for the puzzling behavior of the Br gamma line strength and whether it is correlated with the OI 1.128 micron line behavior. An optical spectrum is presented which shows that HeII lines are the most prominent features - after HI - to be seen in early 2001 April. We present and also discuss spectra taken in 2001 June and August which prominently show coronal lines of [Si VI] and [Si VII] at 1.9641 micron and 2.4807 micron respectively.Comment: Accepted in MNRA

Nova V4444 Sagittarii 1999 in the early decline and quiescent phases

We present near-infrared and optical spectra of the fast nova V4444 Sagittarii at two single epochs in the early decline phase and unfiltered images obtained in quiescence. Based on this and other available data, we discuss about the nature of this nova, including the possibility of it being a recurrent nova

AN IN VITRO STUDY OF CINNAMOMUM ZEYLANICUM AS NATURAL INHIBITOR OF ANGIOTENSIN-CONVERTING ENZYME (ACE) ON SHEEP (OVIS ARIES) TISSUES

Objective: The present study was aimed to find the angiotensin-converting enzyme (ACE) inhibitory activity using the methanolic extract ofCinnamomum zeylanicum (as a natural inhibitor) on sheep tissues as the enzyme source.Methods: Hippuryl-histidyl-leucine (HHL) as a substrate, tissue ACE activity was measured spectrophotometrically at 228 nm. For an incubationperiod of 30 minutes at 37°C, the linearity of ACE activity of kidney, lung, and testis enzyme was established. A known medicinal plant C. zeylanicumwas used as natural inhibitor of ACE. In this enzyme assay, inhibitory effect of methanolic extract of C. zeylanicum on kidney, lung and testicular ACEwas determined. ACE activity was confirmed by captopril, a standard inhibitor of ACE.Results: In the presence of a methanolic extract of C. zeylanicum (10:1), ACE activity was determined and this has inhibited ACE activity verysignificantly. C. zeylanicum leaves extract has reduced sheep kidney, lung, and testis ACE activity by 70.06%, 12.63%, and 20.23%, respectively.Conclusion: Significant inhibition was observed in the kidney ACE than in lung and testis ACE activity. This can propose that there may be a possiblerole in controlling blood pressure or reduction in cardiovascular diseases. Some plants with the great medicinal property may be considered aspromising sources of natural inhibitors of ACE for medicine and commercial uses. This comprehensive study may show numerous beneficial effects asa potential therapeutic agent for lowering blood pressure.Keywords: Angiotensin-converting enzyme, Natural angiotensin-converting enzyme inhibitor, Kinetic assay, Hippuryl-histidyl-leucine, Cinnamomumzeylanicum, Cardiovascular diseases

UNIPOLAR VERSUS BIPOLAR UNCEMENTED MODULAR HEMIARTHROPLASTY IN PATIENTS WITH DISPLACED FEMORAL NECK FRACTURES: A THREE YEAR FOLLOW-UP

ABSTRACTObjective: Fractures of neck of femur are common fractures in the elderly. To keep up an imperative distance from the poor results of internalfixation and early ambulation of patients, hemiarthroplasty is performed. There is a lacking evidence to bolster the choice between unipolar or bipolarhemiarthroplasty, let alone the modularity of modern components. The objective of this study was to assess and look at the consequences of modernunipolar and the modern bipolar prosthesis in terms of clinical outcome.Methods: This was an observational study comprising 39 patients above 60 years of age with fracture of the femoral neck. Patients were distributedrandomly to surgical treatment by either unipolar or bipolar hemiarthroplasty, using modular components, in the department, between December2013 and September 2015. Outcome was assessed and analyzed primarily using Harris hip score (HHS) and radiological parameters with a follow-upof 6 months.Results: The mean HHS at 6 months in bipolar and unipolar divisions was 75.82±2.37 and 77.00±2.59 points. Range of movement median was175° and 166° with bipolar and unipolar groups, respectively. Weight bearing mobilization and daily activities were earlier in the bipolar unit.Complications such as prosthesis dislocation were experienced in the modular bipolar unit compared to high-grade infection with the modularunipolar unit.Conclusion: Both groups of patients were associated with comparative mean HHSs. There were no additional clinical or functional advantages foreither prosthesis. The complications were limited in both groups. Our outcomes are in coincidence with previously done studies using cementedprostheses.Keywords: Hemiarthroplasty, Modular, Modern, Uncemented, Femur neck, Orthopedic surgery