Pulsar timing is a promising method for detecting gravitational waves in the nano-Hertz band. In his prize winning Ph.D. thesis Rutger van Haasteren deals with how one takes thousands of seemingly random timing residuals which are measured by pulsar observers, and extracts information about the presence and character of the gravitational waves in the nano-Hertz band that are washing over our Galaxy. The author presents a sophisticated mathematical algorithm that deals with this issue. His algorithm is probably the most well-developed of those that are currently in use in the Pulsar Timing Array community. In chapter 3, the gravitational-wave memory effect is described. This is one of the first descriptions of this interesting effect in relation with pulsar timing, which may become observable in future Pulsar Timing Array projects. The last part of the work is dedicated to an effort to combine the European pulsar timing data sets in order to search for gravitational waves. This study has placed the most stringent limit to date on the intensity of gravitational waves that are produced by pairs of supermassive black holes dancing around each other in distant galaxies, as well as those that may be produced by vibrating cosmic strings. Rutger van Haasteren has won the 2011 GWIC Thesis Prize of the Gravitational Wave International Community for his innovative work in various directions of the search for gravitational waves by pulsar timing. The work is presented in this Ph.D. thesis.

This book offers review chapters written by invited speakers of the 3rd Session of the Sant Cugat Forum on Astrophysics - Gravitational Waves Astrophysics. All chapters have been peer reviewed. The book goes beyond normal conference proceedings in that it provides a wide panorama of the astrophysics of gravitational waves and serves as a reference work for researchers in the field.

In this thesis, ultimate sensitive measurement for weak force imposed on a suspended mirror is performed with the help of a laser and an optical cavity for the development of gravitational-wave detectors. According to the Heisenberg uncertainty principle, such measurements are subject to a fundamental noise called quantum noise, which arises from the quantum nature of a probe (light) and a measured object (mirror). One of the sources of quantum noise is the quantum back-action, which arises from the vacuum fluctuation of the light. It sways the mirror via the momentum transferred to the mirror upon its reflection for the measurement. The author discusses a fundamental trade-off between sensitivity and stability in the macroscopic system, and suggests using a triangular cavity that can avoid this trade-off. The development of an optical triangular cavity is described and its characterization of the optomechanical effect in the triangular cavity is demonstrated. As a result, for the first time in the world the quantum back-action imposed on the 5-mg suspended mirror is significantly evaluated. This work contributes to overcoming the standard quantum limit in the future.

This thesis describes the essential features of Moon-plasma interactions with a particular emphasis on the Earth's magnetotail plasma regime from both observational and theoretical standpoints. The Moon lacks a dense atmosphere as well as a strong intrinsic magnetic field. As a result, its interactions with the ambient plasma are drastically different from solar-wind interactions with magnetized planets such as Earth. The Moon encounters a wide range of plasma regime from the relatively dense, cold, supersonic solar-wind plasma to the low-density, hot, subsonic plasma in the geomagnetic tail. In this book, the author presents a series of new observations from recent lunar missions (i.e., Kaguya, ARTEMIS, and Chandrayaan-1), demonstrating the importance of the electron gyro-scale dynamics, plasma of lunar origin, and hot plasma interactions with lunar magnetic anomalies. The similarity and difference between the Moon-plasma interactions in the geomagnetic tail and those in the solar wind are discussed throughout the thesis. The basic knowledge presented in this book can be applied to plasma interactions with airless bodies throughout the solar system and beyond.

This thesis develops new and powerful methods for identifying planetary signals in the presence of "noise" generated by stellar activity, and explores the physical origin of stellar intrinsic variability, using unique observations of the Sun seen as a star. In particular, it establishes that the intrinsic stellar radial-velocity variations mainly arise from suppression of photospheric convection by magnetic fields. With the advent of powerful telescopes and instruments we are now on the verge of discovering real Earth twins in orbit around other stars. The intrinsic variability of the host stars themselves, however, currently remains the main obstacle to determining the masses of such small planets. The methods developed here combine Gaussian-process regression for modeling the correlated signals arising from evolving active regions on a rotating star, and Bayesian model selection methods for distinguishing genuine planetary signals from false positives produced by stellar magnetic activity. The findings of this thesis represent a significant step towards determining the masses of potentially habitable planets orbiting Sun-like stars.

This book presents the proceedings of the 2nd Karl Schwarzschild Meeting on Gravitational Physics, focused on the general theme of black holes, gravity and information.Specialists in the field of black hole physics and rising young researchers present the latest findings on the broad topic of black holes, gravity, and information, highlighting its applications to astrophysics, cosmology, particle physics, and strongly correlated systems.

The zodiac was first clearly defined by the Babylonians some 2500 years ago, but until recently the basis of this original definition remained unknown. This zodiac of the Babylonians, known as the sidereal zodiac because it is specified in direct relation to the stars (Latin sideris, 'starry'), was used for centuries throughout the ancient world, all the way to India, and must be distinguished from the tropical zodiac in widespread use by astrologers in the West today, which was introduced only in the middle of the second century A.D. by the Greek astronomer Claudius Ptolemy. Such was Ptolemy's influence, however, that the tropical zodiac gained prominence and, except for its survival (in a variant form) in India, knowledge of the sidereal zodiac was lost. In this thrilling study of the history of the zodiac, first submitted in 2004 as his Ph.D. thesis, Robert Powell rescues the the sidereal zodiac from the dusts of time, tracing it back to the Babylonians in the sixth/fifth centuries B.C. The implications of this discovery-among them the restitution of the sideral zodiac to its rightful place at the heart of astrology-are immense, they key point being that the signs of the sidereal zodiac, each thirty degrees long, coincide closely with the twelve astronomical constellations of the same name, whereas the signs of the tropical zodiac, since they are defined in relation to the vernal point, now have no direct relationship to the corresponding zodiacal constellations, owing to the precession of the equinoxes.This revolutionary history of the zodiac includes chapters on the Egyptian decans and the Hindu nakshatras, showing how these sidereal divisions, which originated in Egypt and India, are related to the original Babylonian zodiac. It also sheds light on the controversy surrounding the 'zodiac question' (tropical vs. sidereal), illuminating the history of the tropical zodiac-showing that originally it was not a zodiac at all, but a calendar for describing the course of the seasons This book, the fruit of thirty years of research, is intended not only for scholars but for general readers as well, and offers the clearest and most comprehensive study of the history of the zodiac yet published.

Winner of the 2021 Donald E. Osterbrock Book Prize for Historical Astronomy In Decoding the Stars, Ileana Chinnici offers an account of the life of the Jesuit scientist Angelo Secchi (1818-1878). In addition to providing an invaluable account of Secchi's life and work-something that has been sorely lacking in the English-language scholarship-this biography will be especially stimulating for those interested in the evolution of astrophysics as a discipline from the nineteenth century onward. Despite his eclecticism, reminiscent of the natural philosophers of the seventeenth and eighteenth centuries, Secchi was in many ways a very modern scientist: open to innovation and cooperation, and a promoter of popularization and citizen science. Secchi also appears fully inserted in the cultural context of his time: he participated in philosophical and scientific debates, spread new theories and ideas, but also suffered the consequences of political events that marked those years and impacted on his life and activities.

How does it happen that billions of stars can cooperate to produce the beautiful spirals that characterize so many galaxies, including ours? This book reviews the history behind the discovery of spiral galaxies and the problems faced when trying to explain the existence of spiral structure within them. In the book, subjects such as galaxy morphology and structure are addressed as well as several models for spiral structure. The evidence in favor or against these models is discussed. The book ends by discussing how spiral structure can be used as a proxy for other properties of spiral galaxies, such as their dark matter content and their central supermassive black hole masses, and why this is important.

Nature is characterized by a number of physical laws and fundamental dimensionless couplings. These determine the properties of our physical universe, from the size of atoms, cells and mountains to the ultimate fate of the universe as a whole. Yet it is rather remarkable how little we know about them. The constancy of physical laws is one of the cornerstones of the scientific research method, but for fundamental couplings this is an assumption with no other justification than a historical assumption. There is no 'theory of constants' describing their role in the underlying theories and how they relate to one another or how many of them are truly fundamental. Studying the behaviour of these quantities throughout the history of the universe is an effective way to probe fundamental physics. This explains why the ESA and ESO include varying fundamental constants among their key science drivers for the next generation of facilities. This symposium discussed the state-of-the-art in the field, as well as the key developments anticipated for the coming years.

A physicist and an inventor, Jules Janssen (1824-1907) devoted his life to astronomical research. He spent many years traveling around the world to observe total Solar eclipses, demonstrating that a new era of science had just come thanks to the use of both spectroscopy and photography, and persuading the French Government of the necessity of founding a new observatory near Paris. He became its director in 1875. There, at Meudon, he began routine photographic recordings of the Sun surface and had a big refractor and a big reflector built. Meanwhile, he also succeeded in building an Observatory at the summit of Mont-Blanc. The story of this untiring and stubborn globe-trotter is enriched by extracts of the unpublished correspondence with his wife. One can thus understand why Henriette often complained of the solitude in which she was left by her peripatetic husband: "There are men who leave their wives for mistresses; you do it for journeys!" ... Basking in the glow of his success, Janssen was able to undertake the construction of the great astrophysical observatory of which he had dreamed. It was at Meudon that he had it built.

The large telescope at Meudon has become legendary. When it was conceived, after 1870, astronomy as a whole was limited to visual observation. Knowledge of the sky was limited to what one could see, assisted only by optical means. The large telescopes produced at this time produced larger images, permitting close-up views: the Meudon telescope was able to accomplish this perfectly. At Meudon, which became the Mecca of visual observation, the major planets were examined in a way that no other telescope had previously been able to. The telescope monitored the state of their atmospheres and mapped the appearance of their surfaces. Through the telescope, one could obtain photographs showing the nuclei of comets, revealing their very small size, and by using an eyepiece one could measure the separation of double stars. With a marvellous little instrument, the polarimeter, the nature of clouds in planetary atmospheres has been determined, and the type of surface material identified. Many more results were obtained, while photography, universally adopted, revolutionized other knowledge about the world. The sensitive emulsion, combined with large aperture reflecting telescopes, revealed the deepness and richness of the cosmos. The vast telescope of Meudon, which was the largest refracting telescope in Europe, became a legendary instrument and was symbolic of a new way to practice astronomy. Audouin Dollfus, a renowned astronomer, describes the great years of the Meudon telescope. He gives us the entire story of this instrument, from the birth of the concept that drove Jules Janssen at the end of the nineteenth century, to the idea that French astronomy could provide an outstanding telescope which would approach the limits of technical and industrial resources. The telescope remained unchanged until 2006, when the first steps toward restoration and public reopening were taken.

The Ptolemaic system of the universe, with the earth at the center, had held sway since antiquity as authoritative in philosophy, science, and church teaching. Following his observations of the heavenly bodies, Nicolaus Copernicus (1473-1543) abandoned the geocentric system for a heliocentric model, with the sun at the center. His remarkable work, On the Revolutions of Heavenly Spheres, stands as one of the greatest intellectual revolutions of all time, and profoundly influenced, among others, Galileo and Sir Isaac Newton.

This book is a collection of essays written by the very scientists and engineers who have led, and continue to lead, the scientific quest known as SETI, the search for extraterrestrial intelligence. Divided into three parts, the first section, 'The Spirit of SETI Past', written by the surviving pioneers of this then emerging discipline, reviews the major projects undertaken during the first 50 years of SETI science and the results of that research.

In the second section, 'The Spirit of SETI Present', the present-day science and technology is discussed in detail, providing the technical background to contemporary SETI instruments, experiments, and analytical techniques, including the processing of the received signals to extract potential alien communications.

In the third and final section, 'The Spirit of SETI Future', the book looks ahead to the possible directions that SETI will take in the next 50 years, addressing such important topics as interstellar message construction, the risks and assumptions of interstellar communications, when we might make contact, what aliens might look like and what is likely to happen in the aftermath of such a contact.

This book is the result of a working group sponsored by ISSI in Bern, which was initially created to study possible ways to calibrate a Far Ultraviolet (FUV) instrument after launch. In most cases, ultraviolet instruments are well calibrated on the ground, but unfortunately, optics and detectors in the FUV are very sensitive to contaminants and it is very challenging to prevent contamination before and during the test and launch sequences of a space mission. Therefore, ground calibrations need to be confirmed after launch and it is necessary to keep track of the temporal evolution of the sensitivity of the instrument during the mission.
The studies presented here cover various fields of FUV spectroscopy, including a catalog of stellar spectra, datasets of Moon Irradiance, observations of comets and measurements of the interplanetary background. Detailed modelling of the interplanetary background is presented as well. This work also includes comparisons of older datasets with current ones. This raises the question of the consistency of the existing datasets. Previous experiments have been calibrated independently and comparison of the datasets may lead to inconsistencies. The authors have tried to check that possibility in the datasets and when relevant suggest a correction factor for the corresponding data."

In a series of illuminating lectures, Joseph A. Seiss presents a clear picture of astronomical occurrences and inspirations to be found in the Biblical New Testament and Gospels. A superbly insightful Bible commentary, this book contains seventeen lectures, each of which focuses upon a specific astronomical occurrence in the New Testament. Events which draw specific influence from the constellations of the stars are charted, with each star sign identified as important to separate events depicted in the scriptures of the gospels. The nativity of Jesus Christ, wherein the Star of Bethlehem appears to the three wise men, is perhaps the most obvious incident of the astronomical. However, Seiss demonstrates that the stars above are richly significant and play a role in many of the most famous tales of the Bible. For example, when Seiss recounts the story of St. Peter's fishing, he compares the sign of Pisces, which was already widely known in the Biblical era.