00057 - Astronomy

Learning outcomes

The aim of the course is to provide the fundamental knowledge of the Earth, the Solar System, the Stars and the Galaxy, as well as the indispensable notions to describe the orbital motions (the two-body problem) and the astronomical observations, such as the determination of the position of cosmic objects, their distance and the measurement of the emitted radiation.

Course contents

COURSE SYLLABUS

The course is divided into two modules, the first taught by Professor A. Cimatti and the second by Professor M. Moresco. The content of the modules is consistently linked to the knowledge and skills that students develop to acquire general competencies in modern Astronomy/Astrophysics.

MODULE 1

- Introduction to spherical trigonometry. Astronomical coordinate systems. Apparent motions of celestial bodies. Coordinate perturbations. Time and its measurement. Constellations.

- The motion of celestial bodies. The two-body problem. Kepler's laws.

- The Earth. Climate zones, seasons. The Moon. Eclipses. Tidal forces.

- Introduction to atomic processes. Atomic structure. Electronic transitions. Spectral lines.

- Radiation from astronomical objects. Definitions. Luminosity. Flux. Surface brightness. Spectra. Apparent and absolute magnitudes. Color indices. Extinction.

- Introduction to blackbody radiation. Planck's law. Wien's law. Stefan-Boltzmann law.

MODULE 2

- The Solar System. Inner planets. Outer planets. Minor bodies. Origin of the Solar System.

- Spectral classification of stars. Hertzsprung-Russell diagram. - The Sun. Structure. Energy production and transfer. The Sun's influence on Earth.

- Binary stars. Classification. Mass estimation. The mass-luminosity relationship.

- Notes on the evolutionary significance of the H-R diagram.

- Variable stars.

- Stellar clusters and populations.

- Exoplanets: discovery methods and observed properties.

- Our Galaxy. Structure and components. Rotation curve. Dark matter.

- The cosmic distance ladder.

- Exercises in which students apply the methods learned in lectures to problems determining astronomical distances and the properties of astrophysical objects, with the aim of gaining familiarity with investigation and calculation techniques.

Readings/Bibliography

The primary reference for exam preparation is the following text in English, or its Italian translation depending on student needs or preferences:

• Karttunen H. et al., "Fundamental Astronomy," Springer Verlag.

• Karttunen H. et al., "Fondamenti di Astronomia," UTET Università.

With reference to the index of the text "Fundamental Astronomy" (which can be easily translated from the Italian version), the following list indicates whether a topic does not need to be studied (indicated by "NO"), or whether it is sufficient to acquire only the essential elements (indicated by "CENNI"). For topics indicated by "handouts," students are required to use the material made available on the Virtual Platform. In all other cases, the topics must be studied following the text. Finally, the slides shown during the course are made available weekly via the Virtuale online platform and can be used as a guide to the topics covered in class and as supplements in cases where the textbook is insufficient (e.g., exoplanets). It is emphasized that the slides are not a substitute for the textbook, but rather complement it.

TOPICS TO STUDY IN THE TEXT “FUNDAMENTAL ASTRONOMY”

1. Introduction 1.1 The Role of Astronomy. 1.2 Astronomical Objects of Research. 1.3 The Scale of the Universe . 2. Spherical Astronomy. 2.1 Spherical Trigonometry (CENNI). 2.2 The Earth. 2.3 The Celestial Sphere. 2.4 The Horizontal System. 2.5 The Equatorial System. 2.7 The Ecliptic System. 2.8 The Galactic Coordinates. 2.9 Perturbations of Coordinates. 2.10 Positional Astronomy. 2.11 Constellations. 2.12 Star Catalogues and Maps. 2.13 Sidereal and Solar Time. 2.14 Astronomical Time Systems. 2.15 Calendars (NO “Reduction of coordinates”). 4. Photometric Concepts and Magnitudes. 4.1 Intensity, Flux Density and Luminosity. 4.2 Apparent Magnitudes. 4.3 Magnitude Systems. 4.4 Absolute Magnitudes. 4.5 Extinction and Optical Thickness. 5. Radiation Mechanisms 5.1 Radiation of Atoms and Molecules. 5.2 The Hydrogen Atom. 5.4 Quantum Numbers, Selection Rules, Population Numbers. 5.6 Continuous Spectra. 5.7 Blackbody Radiation. 5.8 Temperatures. 6. Celestial Mechanics. 6.1 Equations of Motion (dispensa). 6.2 Solution of the Equation of Motion (dispensa). 6.3 Equation of the Orbit and Kepler’s First Law (dispensa). 6.4 Orbital Elements CENNI. 6.5 Kepler’s Second and Third Law (vedere dispensa). 6.6 Systems of Several Bodies CENNI. 6.9 Escape Velocity (dispensa). 6.11 The Jeans Limit (dimostrazione in slide). 7. The Solar System. 7.1 Planetary Configurations. 7.2 Orbit of the Earth and Visibility of the Sun. 7.3 The Orbit of the Moon (Tides: dispensa). 7.4 Eclipses and Occultations. 7.5 The Structure and Surfaces of Planets. 7.6 Atmospheres and Magnetospheres. 7.7 Albedos (CENNI). 7.9 Thermal Radiation of the Planets. 7.10 Mercury. 7.11 Venus. 7.12 The Earth and the Moon. 7.13 Mars. 7.14 Jupiter. 7.15 Saturn. 7.16 Uranus and Neptune. 7.17 Minor Bodies of the Solar System. 7.18 Origin of the Solar System. 8. Stellar Spectra. 8.1 Measuring Spectra. 8.2 The Harvard Spectral Classification. 8.3 The Yerkes Spectral Classification. 8.4 Peculiar Spectra. 8.5 The Hertzsprung--Russell Diagram. 8.6 Model Atmospheres (CENNI). 8.7 What Do the Observations Tell Us? 9. Binary Stars and Stellar Masses. 9.1 Visual Binaries. 9.2 Astrometric Binary Stars. 9.3 Spectroscopic Binaries. 9.4 Photometric Binary Stars. 12. The Sun. 12.1 Internal Structure. 12.2 The Atmosphere. 12.3 Solar Activity. 13. Variable Stars. 13.1 Classification. 13.2 Pulsating Variables. 13.3 Eruptive Variables. 16. Star Clusters and Associations. 16.1 Associations. 16.2 Open Star Clusters. 16.3 Globular Star Clusters. 17. The Milky Way. 17.1 Methods of Distance Measurement. 17.3 The Rotation of the Milky Way. 17.4 Structural Components of the Milky Way. 17.5 The Formation and Evolution of the Milky Way.

Teaching methods

Lectures are delivered face-to-face using both slides (as visual aids) and a traditional blackboard for proofs, examples, and exercises. The exercises at the end of Module 2 are introduced by lectures, followed by teacher-supervised workgroups where students complete the assigned tasks in class and submit their results.

Assessment methods

To best prepare for exams, students are encouraged to attend the course regularly until its end. In the event of absences or working students, missed lectures can be made up for thanks to the slides made available weekly online. The exams are oral, held at the blackboard (except for special needs) and last approximately 30-40 minutes, during which the student is typically examined by both instructors of the two modules. During the exams, 3-4 questions are asked to assess learning and, above all, the student's ability to coherently connect the various topics of the course and the exercises, ensuring that the basic elements of astronomy knowledge have been acquired. The exam assesses both general knowledge and the student's ability to perform (and replicate) the physical and mathematical proofs illustrated by the instructors during the course. This is all aimed at encouraging and activating a process of informed self-assessment among the student. The exam is graded out of 30, with the following final grade gradation: 18-20: very limited preparation and limited independent analysis skills; 21-25: intermediate preparation and moderate independent analysis skills; 26-29: extensive but not complete preparation, good/very good independent analysis skills; 30-30L: complete preparation and excellent/excellent independent analysis skills. Please note that a grade can be declined a maximum of two times. Students can register for exams through the Almaesami platform. Students with learning disabilities or temporary or permanent disabilities: please contact the relevant University office promptly (https://site.unibo.it/studenti-con-disabilita-e-dsa/it ). The office will advise students of possible adjustments, that will be submitted to the professor for approval 15 days in advance. He/she will evaluate their suitability also in relation to the academic objectives of the course.

 

Teaching tools

Traditional blackboard. Projector for computer presentations. Projection of the computer screen in the classroom to show websites, animations, and images on specific topics.

Office hours

See the website of Andrea Cimatti

See the website of Michele Ennio Maria Moresco