LINKS TO COURSE WEBPAGES

Special Relativity   Dr. Norman Gray

Introduction to General Relativity       Dr. Martin Hendry

Observational Astrophysics       Dr. Graham Woan

Theoretical Astrophysics       Dr. Graham Woan

Stars and Their Spectra             Dr. Lyndsay Fletcher

1.1 A brief Overview

This is a 30 credit module, designed to be a link between the elementary astronomy of level 1 and a combined honours degree in Astronomy and Physics, or Astronomy and Mathematics.
The class consists of lectures on Mondays and Wednesdays, together with a class tutorial or a small group supervision session, or occasionally a third lecture, on Fridays. Thus Astronomy 2 students attend on 3 days per week, throughout the three terms (but only for 6 weeks in the third term).  Laboratory sessions are held at the Garscube Observatory: 12 sessions spread over the first two terms, during which 4 experiments are completed by students working in teams.  There is also a weekend observing trip early in the second term, in which we use our stock of modern telescopes for night sky observation.

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Fast Facts
Class & Lab Head	Dr M A Hendry,   Room 607,   tel  ext 5685,      email martin@astro.gla.ac.uk
Lectures/tutorials	Mon, Wed & Fri at 11.00, in Bower Lecture Theatre, Bower Building
Labs	Friday 14.30-17.30, Garscube Observatory. Six sessions in each of terms 1 & 2.
Entry Reqmts	at least 20 grade points per credit accumulated from A1X and A1Y
Prize	The top student in the year will be awarded a cash prize.
Exams	Formative: Class tests (50 mins) in terms 1&2  Summative: written paper in June (75%) + lab and class exercises (25%).
Status	A2Z is a 30 credit level 2 module in the Faculty of Science.

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1.2 Course Aim & Learning Objectives

Course Aim

Astronomy 2 forms a bridge between Levels 1 and 3, consolidating the elementary material and introducing more advanced concepts in preparation for Honours.

Astronomy 2 focuses on 4 main themes: Observational and Theoretical Astrophysics, Stars and their Spectra, and Relativity and Gravitation.

On completing this course, students will have a clear understanding of:

• Modern astronomical observations and instrumentation
• Stellar phenomenology and classification
• Quantum and statistical concepts in an astrophysical context
• The principles of special and general relativity.

On successful completion of this course, a student should be able to:

• Describe modern astronomical methods and instrumentation design
• Demonstrate a practical experience of making astronomical observations, data collection and manipulation, and the ability to use appropriate laboratory apparatus
• Explain clearly stellar phenomenology, including classification schemes and spectral features
• Show a clear grasp of basic quantum and statistical concepts, and proficiency in applying such concepts in an astrophysical context
• Apply the fundamental concepts of relativity and gravitation, with an appreciation of the underlying principles of General Relativity.

1.3 Lecture Courses

The course has 4 main themes:

Observational Astrophysics

Expanding on Astronomy 1, these 10 lectures will investigate quantitatively the observational tools and methods of data collection and reduction which underpin modern astrophysical observations. Quantitative material will also be presented to enable 'rule of thumb' estimates to be made of signal-to-noise ratios associated with various relevant experiments and measurements.

Stars and their Spectra

These 10 lectures extend the basic knowledge gained in Astronomy 1 related to stellar phenomena, and will consolidate understanding of the laws of radiation. Methods of stellar classification will be presented in greater depth, and will include observational criteria for luminosity determination. A range of stellar phenomenology and behaviour will be presented together with basic astrophysical interpretations.

Theoretical Astrophysics

A key area of astrophysics is the interpretation of spectra from many forms of cosmic source, such as planets, stars and nebulae. This requires awareness of the relevant atomic and radiation coefficients, and of the statistical distribution of photons, electrons and ions in such sources. These 15 lectures will outline the basics of the required physics, and apply them to astrophysical situations. (Note: the first 10 lectures will be given by Dr. Woan, and the final 5 lectures will be given by Dr. Diver).

Relativity and Gravitation

A 15 lecture course designed to give a quantitative account of special relativity, with particular applications in astronomy. The lectures introduce the relativistic kinematics required in high energy astrophysics and present the concepts of metrics and curvature, as an introduction to general relativity and theoretical cosmology. (Note: the first 10 lectures will be given by Dr. Gray, and the final 5 lectures will be given by Dr. Hendry).

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USE OF AIMS AND OBJECTIVES.

The brief lecture course descriptions above will be augmented by Aims and Objectives, and course summaries, issued by the lecturer during the lecture course. Students are encouraged to use this guide and the Aims and Objectives for study and as a checklist for revision,but PLEASE NOTE: in response to feedback from students during the year, lecturers may omit or modify some material listed in the Course Component Aims and Objectives. Any such changes will be announced in the course of the year Students are advised not to restrict their study to the topics mentioned, and are expected to think about, read around, and solve problems in these topics, in order to learn how to apply the concepts in unfamiliar contexts.

1.4 Tutorials and Supervision

Tutorial questions are set every fortnight, to be handed in for marking and assessment. Marks scored in your tutorials will count as a continuous assessment element in your overall performance, and a minimum level of continuous assessment work MUST be completed in order to receive ANY credit from A2, so it is vital that you complete each assignment. The maximum score on each tutorial varies from assignment to assignment: check the noticeboards and website for details. Don't restrict yourself to only the set work: read around and try examples from other sources.

Students are allocated to a supervision group consisting of 3 or 4 other students and a staff member acting as supervisor. Each group meets with its supervisor on specified Fridays (see timetable below), continuing into the third term. During these sessions students will have the opportunity to discuss any problems arising in any aspect of the course. To get the best out of these sessions, notify your supervisor in advance of the sorts of problems you want to discuss - you can do this by email, telephone or even on a scrap of paper pushed under the office door. Supervision sessions also provide a forum for more general discussions and even small presentations by the students. They are an essential part of the course: prepare for them, get involved, and you will reap the benefits.

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1.5 Plagiarism

The University's degrees and other academic awards are given in recognition of the candidate's personal achievement. Plagiarism is therefore considered as an act of academic fraudulence and as an offence against University discipline.

Plagiarism is defined as the submission or presentation of work, in any form, which is not one's own, without acknowledgement of the sources. (With regard to essays, reports and dissertations, a simple rule dictates when it is necessary to acknowledge sources. If a student obtains information or ideas from an outside source, that source must be acknowledged. Another rule to follow is that any direct quotation just be placed in quotation marks, and the source immediately cited.)

Where a candidate for a degree or other award uses the work of another person or persons without due acknowledgement:

1. the relevant Board of Examiners may impose a penalty in relation to the seriousness of the offence;

2. the relevant Board of Examiners may report the candidate to the Clerk of Senate, for action under the Code of Discipline, where there is prima facie evidence of an intention to deceive and where sanctions beyond those in (1) might be invoked.

Note that the above warning is not intended to stop you discussing your tutorial problems or laboratory results with your class mates- in fact we encourage this. You should not, however, use someone else's laboratory measurements without acknowledging this, and naming the person, in your record book. Each laboratory report must be your own unaided work. Neither should you submit someone else's tutorial exercise solution as your own.

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1.6 Study Hints

• Clip the Aims & Objectives for each course into the relevant folder of notes, and use them as a template for organising your studies.
• Try and review the lecture notes regularly, and read ahead before the lectures.
• Don't retype or rewrite your lecture notes: this effort is very often worthless, but it does give the illusion of hard work! Instead, try and summarise the material presented: this will force you to concentrate on the key points, and will help you pinpoint exactly where your understanding fails.
• Use your summary notes as a reference guide to reading around, and make sure you consult the course textbook. This activity will also help you prepare for supervision sessions.
• It might be a good idea to form a study group, where a small number get together to sort out difficulties with the course, though this doesn't suit everyone!
• Don't leave exam studying until the last minute. As the date of the A2Z class tests and final examination approach, there will be other pressures on you from other examinations, laboratory deadlines, tutorial questions to catch up on, etc; the time will disappear.
• Try and set aside a fixed period every day to read through your notes and get on with some private study.
• Make use of the library (GUL and the Astrosoc/Physoc library) to get some uninterrupted reading done, and don't stick only to the recommended text.
• Don't forget that Hillhead Public Library is very quiet, and often has spaces where you can work in a different environment, which can sometimes stimulate the jaded student!

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1.7 Laboratories

There are 12 three hour laboratory sessions covering astronomical instrumentation, data gathering and interpretation, and computing, giving a total of 36 hours laboratory work. Students work in pairs and complete at least four experiments: more if time permits, and the best 4 will be used in the practical assessment. There will also be a catch-up lab in each of the first two terms at which attendance is voluntary if your laboratory work is completed and submitted for marking by then.  During these extra labs we may arrange for a video camera with instant playback for those volunteers who wish to give a 10 minute talk on some aspect of laboratory work and get direct feedback in the form of a video replay. In addition to the normal laboratory record of performance, students will be asked to submit two full reports on experiments performed during the session.  A report is due to be submitted at the beginning of terms two and three. Laboratory work contributes to the second year result, and a minimum performance threshold must be satisfied to gain ANY credit from Astronomy 2 (see Minimum Requirements). Note that the Practical score is based on 4 experiments, each worth 10 marks, and two laboratory reports, each worth 20 marks. The laboratory handbook containing details of the experiments and good experimental procedure forms the second half of this document.

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1.8 Class Tests

There will be a 50 minute class test at the end of the first term, and also at the end of the second term. These tests will be held during class time, and will be based on tutorial-type questions. Note that in previous sessions Class Exams were held at the end of each term; this practice is now discontinued, but the past Class Exam Papers are a rich source of questions of degree standard.

The Class Tests are used for feedback; they don't contribute to your overall course grade. However, the continuous assessment element (labwork, lab reports and tutorials) does account for 25% of your grade, with the remaining 75% coming from the end of course examination.

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1.9 Performance Assessment

The following is a paraphrased extract from the current University Calendar. If you need any of the points clarified, it's best to consult your Adviser of Studies.

Grades

Each candidate who has satisfied the minimum requirement for the award of credits shall be awarded a grade, and shall earn the 30 credits for this course, and a number of grade points that depends on the grade awarded (and also on the number of credits for which that grade is awarded). This is summarised in the table below:

Candidates who fail to satisfy the minimum requirements for the course shall earn nothing.

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1.10 Minimum Requirement for the Award of Credits

The following conditions are normally required for the award of grade G and above:

• Attendance at least 50% of the practical laboratory periods and submission of the associated work for marking.
• Attendance at least 50% of the class tutorials and supervisions, and submission of at least 50% of the written work.
• Attendance at the end of course exam and the attainment of an overall mark of at least 15%.

1.11 Resits

A candidate who is awarded a grade A, B, C or D after the first examination diet will not normally be allowed to resit the examination. Any other candidate entitled to sit the end-of-course examination shall be entitled to resit the examination, but normally only once, and at the next available diet. The grade awarded as the result of a resit will be no higher than a grade D.

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1.12 End of Course Examination

This examination is held in term 3, in late May or early June, with the resit examination usually in late August or early September. Both have the same structure and consist of a single two and one half hour paper, single marked by the course lecturers. Past papers are available to the students: make sure you get the relevant copies. Overall performance is determined as follows:
 

Grade D normally requires an overall score of 40%. Grade B, essential for MSci candidates, is normally set at 60%.

Please note that the scores for tutorial and practical elements are assessed on the maximum available points; students must therefore complete all the required work in order to maximise their score.

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1.13 Portfolio of Written Work

As mentioned above, the final assessment is based upon the written paper, the tutorial work and the practical. Since the latter two are elements of continuous assessment, the onus is on the student to maintain a complete record of performance in these areas. This portfolio of completed work must be submitted at the end of term 3 so that it can be examined by the external examiner. This applies to all students. You are therefore strongly recommended to keep a folder of all your tutorial work, and add to it as the year progresses: this will then constitute part of your portfolio. It will be returned to you after your end of course exam, but will be required to be submitted once again if a resit is required. Laboratory record books and Laboratory Reports will be treated similarly.

1.14 Calculators

Students should note that calculators with the facility to display information graphically, or having the capacity to manipulate formulae symbolically, are banned from use during examinations. Candidates must not bring such equipment into the examination hall. Any calculators of this type found during an examination will be removed, and the examination script endorsed accordingly.

Student must comply with the following extract from the Faculty of Science General Information for Students:

Calculators or other hand-held electronic aids with a facility for either textual storage or display, or for graphic display, are excluded from use in examinations.

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1.15 Attendance

Students are required to attend all lectures, tutorials and laboratory sessions. Attendance will be taken at tutorials and labs, and taken randomly during lectures.

If you are absent for medical reasons from one lab session, or from five consecutive lectures, you should complete a Self Certificate of Absence available from the Principal Adviser's Office in the Boyd Orr building, or from the Departmental Secretary, room 508. Please speak to the class / lab head on your return.

In the case of prolonged or frequent absence, a medical certificate must be submitted to the Principal Adviser's office. This must also be done if a student is unable to sit an examination through illness, or if an examination performance has been adversely affected by ill health. More details can be found in the Registry Handbook, or at the Registry web site:

http://www.gla.ac.uk/services/registry/student/studbook/annexb.htm

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1.16 Problems ...

Please don't suffer in silence. If you have any difficulties with the course, whether in understanding the lectures or related to personal circumstances, please don't hesitate to broach the subject with us. You can approach the class head, the lecturers concerned, your adviser of studies or your supervisor. Don?t forget that there are professionals on the campus who can offer confidential and sympathetic advice on personal matters: the Student Counselling Service at 65 Oakfield Avenue is there to help (contact Mrs Florrie Rankine on ext 4528).

1.17 Reading List

The recommended course text book:

An Introduction to Modern Astrophysics, by B W Carrol & D A Ostlie, published by Addison-Wesley ISBN 0-201-54730-9.

This book is considered an essential purchase, and all students are expected to have access to a copy.

For wider background reading, students may find the following list useful:

Principles of Cosmology and Gravitation, by M V Berry, Hilger

Introduction to Stellar Astrophysics, Vol 1: Basic Stellar Observations and Data, by Böhm-Vitense, CUP.

Astrophysical Techniques, Kitchin, Hilger

Astronomical Observations, Walker, CUP

Astronomy - Principles and Practice, 3rd Ed, A E Roy & D Clarke, Hilger

Special Relativity, French, Chapman & Hall

Stars and their Spectra, Kaler, CUP

Fundamental Astronomy, Second Enlarged Edition, H Karttunen, P Kröger, H Oja, M Poutanen and K J Donner, Editors, Springer Verlag

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1.18 Notice Boards and Website

Information on all aspects of the class is available on the notice boards: (i) in the foyer of lecture theatre 257, Kelvin Building; and occasionally (ii) in the glass fronted cupboard in the corridor on level 6, Kelvin Building. Since there is no ?dedicated? notice board outside the Bower Lecture Theatre, you should regard the course website as the main source of information - and your first point of contact for news updates - about A2Z. Get into the habit of checking the course website regularly; you will find links to fresh items of news on the homepage. (Important news items will also be sent by email to all class members, so check your emails regularly too!).  The set work for tutorials will be displayed on the noticeboard and website, as will the lecture timetables and information concerning the laboratory sessions.

1. 19 Observing opportunities

Weather permitting, voluntary night observing sessions may be organised periodically at the Garscube Observatory: keep an eye on the notice boards for further information. There will be an observing trip to a remote, dark site at which students will be able to use state-of-the-art telescopes: please watch the notice boards and website for further information.

1.20 Student - Staff Committee

Astronomy 2 elects one representative to the departmental Student - Staff Committee. Nominations will be called for in October, and the representatives elected before week 5. Agenda and minutes of the committee meetings will be posted on the notice boards.

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1.21 Student facilities

The department provides common room on level 4, open to staff and all students enrolled in departmental courses. The common room has vending machines and can be used for study, though it isn't quiet. The student library is located in room 332 and has a small study area, in which a copy of every course textbook can be found. Access information is displayed on the main notice boards throughout the building, and in the common room itself.

Astrosoc is the student astronomical society, which undertakes to arrange social events and invited talks on burning issues of relevance to modern astronomers. Why not liven up your academic life, and participate socially? Don't forget the other student organisation within the department: Physoc. Membership of these two sociable societies should brighten up many aspects of your departmental career!

1.22 Future Moves

We hope you will continue with your astronomy studies. Astronomy is offered as a Combined Honours degree with either Physics or Mathematics, each at BSc or MSci level; for details about entrance requirements, see the relevant part of the general section in the Departmental Handbook.

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1.23 Provisional Timetable

NG        Dr Norman Gray     Relativity and Gravitation I       10 lectures        Room 615    ext 4268

GW        Dr Graham Woan   Observational Astrophysics I      10 lectures        Room 617    ext 5897
                                            Theoretical Astrophysics I       10 lectures

MAH      Dr Martin Hendry   Relativity and Gravitation II       5 lectures        Room 607    ext 5685

DAD       Dr Declan Diver    Theoretical Astrophysics II       5 lectures        Room 606     ext 5686

LF           Dr Lyndsay Fletcher     Stars and Their Spectra        10 lectures        Room 618    ext 0093

2.1 Timing & Location

The class meets on six Friday afternoons in each of  terms 1 and 2 at the Observatory at Acre Road, off Maryhill Road. Attendance is from 2.30 to 5.30 p.m. The dates for each term will be notified separately. There will be a catch-up lab at the end of each term's lab allocation, so that students can finish off experiments, if necessary.

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2.2 Objectives of the course

The aim of the class is to introduce various techniques of astronomical measurement and of data analysis. It is intended that the class will develop further your skills for making measurements, for analysis of data, for working co-operatively with others and for the presentation of written reports.

Specifically, the practical sessions are designed to

• illustrate and expand upon material presented in the lecture courses, and where required, introduce new material germane to the education of a professional astronomer.
• demonstrate the physical principles underlying observational astronomy, from data collection to data processing and interpretation
• impart skills in the deployment and use of instrumentation and techniques appropriate to detection and measurement of various physical and astronomical quantities
• assist the clear, concise and accurate reporting of a performed experiment

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2.3 Laboratory Assessment

Working in pairs

You will work in pairs and are required to complete a minimum of four experiments from the list given below with three afternoons allowed for each. It is expected that each member of a pair will co-operate with the other to ensure that the work is shared equitably and carried out efficiently This will help develop the personal skills and attitudes which are required to operate within a group.

There have been occasional cases in the past in which a student has only attended on one of the three afternoons allocated to an experiment but has handed in a report for the experiment and claimed credit for having carried out the work. This is clearly not satisfactory and it will be necessary for each student to demonstrate that he or she was present during the carrying out of an experiment and participated fully in it before being able to claim credit for it. However, due allowances will be made for illness or other unavoidable circumstances which might cause absence from the practical class.

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Laboratory Records

You each must have a suitable lab book, namely a bound A4 book including graph paper. The experiments performed have to be written up fully as lab records, using your lab book. This book will be used to record ALL data, to graph results and to record conclusions. Although it does not have to be pristine, it must however describe clearly all measurements undertaken, including a full disclosure of all data and equipment used, and must state equally clearly the results and conclusions of the experiment you performed. Sufficient theory should be included to make the account clear and understandable; you may wish to make additional notes relevant for the laboratory report.

There is sufficient time allocated within the laboratory sessions to enable you to complete a lab record; you will not normally be allowed to proceed to another experiment without presenting a definitive record of an experiment. Remember the key points:

• read the lab sheets, and make sure you know what you are required to do; ask a demonstrator if it's not clear.
• write a brief description of the experimental objectives in your lab book before you start to record the data!
• record your data thoroughly, and plot all graphs as you take the data; this will help you identify poor data, and allow you to repeat measurements if necessary.
• Make sure your graph fits the paper: scan through the likely range of measurements, and scale the graph accordingly. Circle each data point as you plot it, so that real data is easily distinguished from random marks on the paper!
• quantify the uncertainties (errors) of your measurements and your final results
• make sure you complete all aspects of the experiment
• present your results clearly, and summarise the performance of the experiment.

Marking Scheme

The marking scheme for a lab record is usually as follows:

Note that the neatness or otherwise of the lab record will not feature significantly in the assessment; as long as the lab is legible, the criteria above will be applied to the content, rather than the presentation. If you have any queries about the mark you received for a particular experiment, don't hesitate to raise it with the lab head.

Laboratory Reports

Two of your completed experiments must be written up fully as reports as part of the "continuous assessment" element of the course; guidelines about what is expected from the reports are included in this document. Normally one report will be required per term. Each lab report is marked out of 20.

Demonstrators

There will be two demonstrators and the lab head at each session. Please don?t hesitate to ask if there is anything unclear about the experiment. The staff will come round each experiment periodically and ask to see your lab record, so please keep it up to date. Demonstrators will judge whether or not an experiment has been completed on the basis of your lab notes; the record books will be marked by the class head, though you may be allowed to proceed to another experiment before this happens, depending on the prevailing circumstances.

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Laboratory Sheets

Detailed descriptions of each experiment are maintained as Laboratory Sheets, available from the demonstrators. Since apparatus is continually being updated and improved, the lab sheets are held centrally to avoid inappropriate notes being distributed. Please retain your lab sheets for future reference, but don?t use them to record data!

2.4 List of Experiments

Below is a brief summary of the experiments offered at the Acre Road Observatory:

1. Filter photometry
The aim of this experiment is to introduce and produce familiarity with some of the concepts associated with a magnitude system and the measurements of stellar magnitudes.   Specifically, it introduces bolometric correction, colour index and colour excess.   It is a laboratory simulation.

2. Period fitting of data
This is a computer based experiment and involves the measurement of the periods of a set of Cepheid variable stars, with the aim of verifying the Period-Luminosity relation for these objects.   It demonstrates simple methods for obtaining the period from time series data, and illustrates the concept of the standard candle.

3. Spectrophotometry
Spectral line profiles of a star and a nova are compared, using spectra recorded on a photographic plate and analysed by a microdensitometer.  The equipment allows the density of any image on a plate to be measured directly, and also permits calibration of the density in terms of intensity.

4. Stellar Classification
An experiment in which film copies of  UK Schmidt Telescope objective prism photographs are used to provide low resolution spectra of large numbers of objects.  Classification of the stars in the field is possible, using the characteristics of these spectra.  The results of the survey can be interpreted in terms of Galaxy composition.

5. Atomic Lines
Detailed analysis of spectral lines from discharge lamps using a grating spectrometer. Students will examine several lamps, calibrating the spectrometer, before attempting to identify the composition of an unidentified mixture

6. Centimetre Optics
Here microwave apparatus is used to explore transmission, reflection, refraction, diffraction and interference of electromagnetic waves at wavelengths much greater than optical.  The results are relevant to radio interferometry, as well as conventional visible optics.

7. Double star measurements
The aim of this experiment is to use a simulated long period visual double star whose orbit can be measured by direct observation of the relative positions of the two stars using a telescope and to use a supplied computer program to fit an ellipse to the resulting data, to determine the ellipse parameters and, hence, to determine the elements of the orbit.

8. Hartmann Test
The aim of this experiment is to measure the properties of a telescope objective using the Hartmann method and hence to determine the best focus position and practical resolving power of the telescope.   It also introduces the use of photographic methods, including darkroom techniques.

9. Starfield photography
The aim of this experiment is to photograph a small region of the sky, which is simulated in the laboratory, and to compare the positions of the stars photographed with those tabulated in a catalogue.   It introduces the use of photographic methods in astronomy and darkroom techniques. The experiment also includes the  measurement of the resulting star plate, the determination of the plate constants and the evaluation of the celestial coordinates of a non-catalogued star.

10. Radial velocity of a star
The aim of this experiment is to determine the radial velocity of a star by comparing the positions of the iron absorption line in its spectrum with a laboratory iron spectrum.   The accuracy of the final result is examined.   It introduces the use of the Doppler shift of spectral lines to measure radial velocities.

11. Study of globular clusters
This experiment uses a photographic negative of part of the Small Magellanic Cloud and is in two parts.   The first part compares the sizes of globular clusters in the of the SMC and a cluster in our galaxy (NGC 104) in order to assess the suitability of using the apparent diameters of globular clusters to measure distances.   The second part involves measuring the spatial distribution of the stars in NGC 104 to determine the tidal radius of the cluster and, from this, to determine the mass of the cluster.

Note that the laboratories are continually being improved, and equipment is regularly being serviced and upgraded. Consequently some of the above experiments may be temporarily unavailable, some others may be slightly changed, and some new ones may be added.
 

2.5 Safety

Students must be aware at all times of the need to work safely in the Observatory. All students are required to read:

1. the Code of Safe Practice for Undergraduate Students;
2. the guidelines on Safety in the Observatory, reproduced below;
3. the guidelines for safe working in the darkroom, reproduced below.

2.6 Safety in the Observatory

The attention of students is drawn to the following points. Many of these are pure common sense; that does not diminish their significance but makes non-observance of them more reprehensible.

The First Aid Officer is Colin Hunter, in the Workshop tel ext. 30.

The First Aid Box is also located in the Workshop.

1. Care must be taken when using any electrical or electronic equipment. This is particularly necessary when using high voltage apparatus, e.g. photomultipliers.

2. Under no circumstances may the sun be viewed directly through any optical aid, however small - telescope, coelostat, etc. Even momentary direct exposure of the eye to focused solar radiation will lead to permanent damage to eyesight, even blindness. So never look directly at the sun through a telescope.

3. The use of photographic chemicals in the darkroom requires caution. Some are poisonous, some corrosive and some may produce skin irritations. Before using any chemical, make sure you are familiar with the accompanying instructions. Use the safety gloves and glasses provided.

4. Equipment in the workshop is not to be used by students. In fact students should regard the workshop as out of bounds unless they have the express permission of the laboratory supervisor or whoever is on duty at the time, or in an emergency request for first aid.
 

5. Telescope / Coelostat Domes

(i a) Telescope Dome: go up and down the stairs carefully, avoiding the upper floor beam with you head.

(i b) Coelostat Dome: in gaining access to the roof, make sure the ladder is secure. Take care with respect to the restricted headroom. Hard hats are available and should be worn.(ii) Make sure that the hooks holding the hatches are secure, and do not use the hatches as a handrail. The hatches must not be left open when the telescope/coelostat is being used or adjusted.

(iii) Keep your hands clear of the rail when the dome-turning motor is in operation. In case of difficulty press the red button to stop the dome-turning motor.

6. Please note the location of the fire exits in the Garscube Observatory:

(i) in the library

(ii) at the end of the corridor between laboratories E and F.

7. Please note: the first aid box is in the workshop; the first aid officer is Colin Hunter, workshop technician.

8. Every experiment has an accompanying instruction sheet. Comments on safety relevant to that experiment are included in the sheet. Study the sheet carefully before beginning the experiment.

9. No student may undertake night observation alone. If the supervisor is not present, students must work in pairs (or in larger groups). There can be no exceptions to this rule.

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2.7 Safe Working in the Darkroom
 
 

Notes on Photographic Procedure

Photographic chemicals are generally caustic and care must be taken with their use. Although the procedures you will be following in the development of roll film keep the chemicals contained, care must still be taken with respect to splashes. Protect your clothing with an apron or lab coat. If your experiment requires the production of prints, this procedure involves the use of development trays. Movement of paper from one tray to another should be done using plastic tweezers and protective gloves should be worn.

• If chemicals do come in contact with your skin or eyes wash immediately with plenty of water.

• Keep the Darkroom well ventilated by using the fan.

Procedures

Although in the professional situation astrophotography of starfields, spectra, etc. would make use of glass plates, it is uneconomical to use this in a teaching laboratory. The Darkroom facilities are essentially for the development of roll film and for the occasional production of prints. Unfortunately all common user black and white film is PANCHROMATIC and can only be handled in complete darkness (until it is secure in the development tank). Development of prints, enlargements, etc. can be undertaken with a "safelight".

It is suggested that the art of loading a film into the development tank should be first practised with normal room illumination - using an old piece of film.

Loading the Development Tank

After taking all the required exposures, rewind the film into its cassette before removing it from the camera.

Set up the development tank parts into an order on the bench. Prepare the film for inserting into the tank spool by cutting off the tapered leader; cut between the slots and not through them. If the leader has been rewound so that its end has disappeared into the cassette, the trimming should be done after opening the cassette - AND this should only be done with the lights switched off and the room in complete darkness!

In total darkness, remove the film from the cassette and thread it into the drum of the tank. This should be done without fingers touching the emulsion as this would mark the exposures.

Within the first spiral of the drum, there is a gripping and advancing device comprising two springed metal balls; once the film has been threaded beyond these, the loading process can be completed by alternately twisting the top and bottom sections of the drum relative to each other. The action should be very smooth and you should be able to sense that the film is being wound into the spiral guides. Cut off the cassette from the last piece of film as it enters the drum.

Place the loaded drum with the black disk at its centre innermost into the development tank. Fit the lid making sure that it is level and locked in position. At this stage the tank is now light-tight and the room lights can be switched on.

Developing a Film

Development chemicals and Fixer should be prepared and set aside. Before pouring chemicals into the tank, check that they are at the right temperature. After measuring out the correct quantities into beakers, adjust the temperature by playing either cold or hot water onto the outside of the beaker. It is important to keep all processing solutions, including wash water, to similar temperatures (± 5° C) in order to avoid mild reticulation.

The Developer should be diluted with water 1 + 1 and the Fixer should be used at full strength. The volumes required for the tank are 290cc or 10 fl. oz. A temperature of 20° C is recommended.

Pour the Developer into the opening at the top of the tank. DO NOT tilt the tank. Insert the black agitator rod and twist the loaded spool within the tank backwards and forwards for a few seconds to dislodge any air-bubbles on the surface of the film. Agitate the film for a few seconds every minute until the full development time has elapsed. At this time pour out the developer. If there is a chance that a second film might be developed during the same session, save the developer in a beaker - otherwise dispense it down the sink, rinsing with plenty of water.

Wash the film by adding water to the tank, agitating the film and then pouring the water away.

Pour in the measured quantity of Fixer and agitate at one-minute intervals until the fixing period is complete. Pour out the Fixer and give the film a good wash for several minutes. This can be done by placing the tank within the sink with its centre directly below the tap and allowing water to pour in continuously.

Remove the tank from the sink and pour out the water. Unscrew the lid and remove the spool. To remove the film from the reel, arch the free end and pull gently, allowing the reel to rotate on the other hand. The whole length of the film should run out easily. Attach it to a clip and hang it up to dry.

PLEASE KEEP THE DARKROOM TIDY

At the end of each development session, pour away the used solutions and wash the tank thoroughly. Run water through the lid from both sides to flush out residual chemicals.

List of equipment in Student Cupboard:

Film Cassettes: Ilford Pan F or FP4

Development Tank

Measuring Cylinders

Electronic Timer : see lab demonstrators or the Lab Technician

Thermometer

Stock Bottles of Developer : Ilford PERCEPTOL or ID 11

Stock Bottle of Fixer: ILFOFIX
 
 

Development Times:

Recommended time (minutes) for "Normal Contrast" development at 20° C with the stock solution mixed 1 + 1 with water:

PanF FP4

PERCEPTOL 12½ 11

ID 11 8½ 9

Extra development time increases the contrast.

Recommended time for Fixing: 5-10 mins at 20°C

If you want to process your film at some other temperature, refer to the chart below. To use this, first find the point corresponding to the recommended time on the 20°C line - see the row of figures in the middle of the chart. Now follow the diagonal line corresponding to this time to the point where it cuts the horizontal line representing the temperature to be used. The approximate new development time will be found vertically below this intersection. For example, if 6 minutes at 20°C is recommended, the time at 22°C will be 5 minutes and at 17°C it will be 8 minutes.

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2.8 GUIDELINES FOR THE WRITING OF REPORTS

The writing of laboratory reports should be treated as an important part of the work of the practical class. Not only does it describe the work which you have carried out and allows the assessment of its quality, but it also provides an essential training in the writing of papers and reports for any subsequent professional career. It is just as an important communications skill as having the ability to present a clear and well reasoned talk and should be treated as such.

Laboratory reports should normally be word-processed using facilities either at the observatory or in the departmental open access cluster. A combination of Word for Windows and Excel should provide the author with an appropriate range of tools (such as text & mathematics typesetting, data tables, graphs etc) for a professional presentation of experimental work undertaken in the laboratory.

It is difficult to provide precise rules for the writing of the laboratory reports for this class because of the wide diversity of experiments but there are some well defined guidelines which can be used and which may serve you well elsewhere at university and after you leave. In the paragraphs below is a suggested layout which satisfies the crucial requirements for a good report:

The first and most important of these is that the report must be written in a way that allows an understanding of the experiment by a person who has no detailed knowledge of the experiment but who has appropriate basic knowledge of the subject. The question to ask yourself is "Could another student in my class carry out this experiment from my report? Am I providing all the necessary information?." This is the essential feature of any satisfactory report but it does not mean that you can simply reproduce the instruction sheets provided for the experiment. Along with the results obtained, this feature of your report demonstrates the extent to which the experiment was understood.

Abstract or Overview

The report should usually begin with a brief but sufficiently complete description of any underlying theory so that the reader can understand the basic principles of what was done. This can assume a reasonable basic knowledge of Astronomy and will be very brief in some cases but it is normally an essential preliminary to the description of the experiment itself. It also serves the important purpose of getting the readers mind into tune with the theory and methods involved in the experiment.

Experimental Apparatus and Method

The next part will usually contain a description of the apparatus and the way in which the experiment was performed. There is no need to give a list the pieces of apparatus involved but this part should be sufficiently complete that, even without any prior knowledge of the apparatus or experiment, the reader will understand clearly what was done. There is no point in saying, for example, "The fringe positions were measured using the microscope" when neither the fringes or microscope have already been introduced. Diagrams are often essential and certainly should be used whenever possible to make the explanation clearer. Although it might seem that these requirements will demand a large section, there is also the need to have the report as brief as possible so that all unnecessary detail has to be minimised. The essential guideline should be "Would I understand what was done in the experiment from reading the report?" and this is what you must apply.

Results

The results obtained and the analysis which gives the final results and conclusions should be in the next section. There should be enough numerical information to allow the reader to reproduce the analysis but there is no need to give the arithmetical details. It is reasonable to assume that the reader will have a calculator. Error analysis should be carried out whenever possible and, if appropriate, comments should be made about the most important sources of the uncertainties in the final results. At all times, the report should demonstrate that the experimental uncertainty in each measurement was considered and that all reasonable efforts were made to assess it and to minimise it.

Conclusions and Discussion

The final part gives the conclusions and any relevant comments on the experiment, including its weaknesses and limitations. Putting your results into a broader context should be done here (eg do your results agree with published data, and if not, why not?).

Obviously, there can be many variations on what has been described. If the experiment has more than one part, the pattern above might be repeated separately for each. Some experiments are computer based. In this case, there might be a large section on the theory behind the analysis carried out, a very small or even no section on the apparatus followed by a large section on the analysis. Use your common sense and, again, always think about how easily you would be able to read the report and understand it.

Do not simply reproduce word for word the contents of the lab sheets!

The normal style of reports is in the third person and this should be used. However, it should not be written as a set of instructions. It is to be a description of what you did and not a recipe.

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2.9 Coffee Break

There will be a 20 minute coffee/tea break in every lab, usually around 4pm. You will be asked to refund the cost of tea-bags, coffee, sugar by contributing nominally each time you use the facilities. Milk and biscuits have to be organised by the students! Please don't forget to wash your cups.

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last updated 25/09/01

M.A. Hendry, Class & Lab Head