V596 Pup is a detached eclipsing binary containing two A1V stars in a 4596-d-period orbit with a small eccentricity and apsidal motion, previously designated as VV Pyxidis. We use new light-curves from the Transiting Exoplanet Survey Satellite (TESS) and published radial velocities to determine the physical properties of the component stars. We find masses of 2098 +0021 M-(R) and 2091 +0018 M-(R), and radii of 2179 +0008 R-(R) and 2139 +0007 R-(R).The measured distance to the system is affected by the light from a nearby companion star; we obtain 1784 + 25 pc. The properties of the system are best matched by theoretical predictions for a subsolar metallicity of Z = 0010 and an age of 570 Myr. We measure seven significant pulsation frequencies from the light-curve, six of which are consistent with delta Scuti pulsations and one of which is likely of slowly-pulsating B-star type.
This broad interest text describes how our current understanding of the interiors of the stars came about, beginning in 1870. It starts by discussing the development of our knowledge of the inside of the Sun, and continues on to compare the Sun's and other stars' properties and then discusses how stars form, evolve, and die. The book describes the properties of a variety of stars with special characteristics, and it ends with a discussion of the first stars that formed after the Big Bang. Aiming to show how interesting scientific investigations can encourage young men and women to pursue STEM careers, this book also underscores the role women have played in the development of our understanding. Key features • Includes the stories of the historical advances that have led to our current understanding of the nature of the stars • Underscores the important roles women have played in the development of this understanding • Avoids the use of technical jargon and clearly defines the terms used • Identifies some of the key questions that remain unresolved at the time of writing
I AM residing in tropical Queensland, lat. 21° S., and consequently am not likely to see any auroral phenomena, particularly in the middle of our hot and rainy season; but last night between 8 and 9 P.M. there occurred the following remarkable appearances, which were seen by me and several others.
IQ Per is a totally-eclipsing binary system containing a B8 V star and an A6 V star in an orbit of period 1.744 d with eccentricity and apsidal motion. We use new light curves from the Transiting Exoplanet Survey Satellite (TESS) and published spectroscopy from Lacy Frueh (1985) to measure the physical properties of the component stars, finding masses of 3.516 +/- 0.050 Msun and 1.738 +/- 0.023 Msun, and radii of 2.476 +/- 0.015 Rsun and 1.503 +/- 0.016 Rsun. Our fit to the light curve is imperfect, with a small sinusoidal trend in the residuals versus orbital phase and a slight mismatch in the depth of secondary eclipse, but the total eclipses mean the system is still well-characterised. The distance to the system from its masses, temperatures, apparent magnitudes and bolometric corrections is in agreement with the parallax distance from Gaia DR3. Theoretical models cannot adequately match the measured properties of the system, and new spectroscopy to confirm the temperatures and determine the chemical compositions of the stars would be useful. A Fourier analysis of the residuals of the best fit to the light curve shows many peaks at multiples of the orbital frequency, and one significant peak at 1.33 c/d which is not. This pulsation and the properties of the primary component are consistent with it being a slowly-pulsating B star.
We present a detailed analysis of the detached eclipsing binary system HO Telescopii, which contains two A-type stars in a circular orbit of period 1'613 d. We use light-curves from the Transiting Exoplanet Survey Satellite ( TESS ), which observed HO Tel in three sectors, to determine its photometric properties and a precise orbital ephemeris. We augment these results with radial-velocity measurements from S & uuml;rgit et al.1 1 to determine the masses and radii of the component stars: M-A = 1'906 + 0'031 M-circle dot , M-B = 1'751 + 0'034 M-circle dot , R-A = 2'296 + 0'027 R(circle dot )and R-B = 2'074 + 0'028 R-circle dot . Combined with temperature measurements from S & uuml;rgit et al.1 1 and optical-infrared apparent magnitudes from the literature, we find a distance to the system of 280'8 + 4'6 pc which agrees well with the distance from the Gaia DR3 parallax measurement. Theoretical predictions do not quite match the properties of the system, and there are small discrepancies in measurements of the spectroscopic orbits of the stars. Future observations from Gaia will allow further investigation of these issues.
V454 Aur is an eclipsing binary system containing two solar- type stars on an orbit of relatively long period (P P = 2702 d) and large eccentricity (e e = 0381). Eclipses were detected using data from the Hipparcos satellite, and a high-quality double- lined spectroscopic orbit has been presented by Griffin1. 1 . The NASA Transiting Exoplanet Survey Satellite ( TESS ) has observed the system during eight sectors, capturing ten eclipses in their entirety. V454 Aur is unusual in that the primary star - the star eclipsed at the deeper minimum - is less massive, smaller, and cooler than its companion. This phenomenon can occur in certain configurations of eccentric orbits when the stars are closer together at the primary eclipse, causing a larger area to be eclipsed than at the secondary. We use the radial-velocity measurements from Griffin and the light-curves from TESS to determine the masses and radii of the component stars for the first time, finding masses of 1034 + 0006 M (R) and 1161 + 0008 M (R) , and radii of 0979 + 0003 R (R) and 1211 + 0003 R (R) . Our measurement of the distance to the system is consistent with that from the Gaia DR3 parallax. A detailed spectroscopic study to determine chemical abundances and more precise temperatures is encouraged. Finally, we present equations to derive the effective temperatures of the stars from the inferred temperature of the system as a whole, plus the ratio of the radii and either the surface brightness or light ratio of the stars.
We demonstrate optimal curve-fitting procedures to the parametrization of a selection of 25 visual-binar y-star orbits from F. W. Dyson's1 catalogue. We compare our findings with other published results, which reveal uncertainties, real and formal, affecting the parameters. The extent of data coverage for any one system can have a substantial impact on the modelled results, with various orbital solutions sometimes possible for a single system.
The Archives of the Royal Observatory Edinburgh preserve the out -going letters of Lord Lindsay's private observatory at Dun Echt, providing a detailed picture of its development and operation during its twenty-year (1872-1892) existence. Nearly all were written by the two astronomers in charge, David Gill until mid -1876, followed by Ralph Copeland until the observatory's merger with the Royal Observatory. Here we look primarily at their communications with other astronomers to consider how the observatory maintained its connections with the astronomical world through correspondence and the exchange of telegrams using the Science Observer code devised in Boston, as well as the publication of the Dun Echt Circulars and Copernicus . Also quoted are some letters which fill the gaps in the published accounts of the observatory to round out our picture of its operation.
V530 And and V719 Her were originally selected in order to test the validity of the extreme rates of period change found in the literature but in both cases these have been dismissed. However, a more detailed examination of the systems has led to the discovery of a small positive period change for V530 And amounting to P (center dot) = + 0010(1) s yr (-1) , which is about an order of magnitude lower than the dispersion seen in W UMa systems. V719 Her on the other hand, in addition to being a very active system, shows a complex pattern of period behaviour. Over the past century the system has undergone two period reversals with triangle P / P = +/- 1 x 10 (-5) through a series of discrete period changes between largely constant -period sections. There is some evidence in the most recent data that there are small oscillations or perturbations, meaning that the linear sections might not be truly constant. Whether this is due to the effect of active regions or a presentation of the wider behaviour is not clear at this time.
The President. Good afternoon and welcome to this A & G Highlights meeting for October. This is a hybrid meeting. Those on-line will be muted and should use the chat facility to ask questions. These will be read out at the end of each It is my great pleasure to introduce our first speaker, Dr. Tim Lichtenberg, winner of the Winton Award in Geophysics for Early Achievement. He got his PhD in 2018 in the Department of Earth Sciences at ETH in Zurich. From 2018-2022 he was SNSF and Simons PDRF in the Atmospheric, Oceanic and Planetary Physics Department at the University of Oxford. Since 2022 he has been Assistant Professor at Kapteyn Astronomical Institute at the University of Groningen. I invite him to give his talk on 'Molten exoplanets as a window into Dr. Tim Lichtenberg. One of the greatest unsolved questions with regard to our origins and the diversity of life in the Universe is what the environment of nascent Earth looked like after planetary formation. Prebiotic synthesis in lab environments has made enormous strides in the past years uncovering chemical conditions that seem suitable to birth life as we know it via chemical means. These emergence paths rely on relatively stable atmospheric settings with a surface ocean and an atmosphere rich in feedstock molecules such as hydrogen cyanide. At the same time, exoplanet science has undergone a tremendous expansion in the number of detected planets, reaching the realm of high-density worlds potentially similar to the Earth in some aspects. However, given that most exoplanets detected via the transit method orbit very close to their star, they receive intense stellar irradiation - seemingly disconnected from the planetary environment that we envision for the early Earth. However, those planets, in fact, enable us to probe key physics and chemistry of the earliest episodes of atmospheric formation of rocky planets in general. In particular, a key constraint on the origin of life is the apparent detachment of nitrogen and carbon oxidation states in extant biomolecules - nitrogen feedstocks are preferred in highly reduced forms, but carbon oxidation
