Acknowledgements Some of the material written below may not apply to the specific software or services that are mentioned here. We hope that you will all understand that this article was originally presented to an astronomy club in the Metropolitan Toronto area. If you wish to post any area specific information that would pertain to your region it is invited and most welcome. Any revisions or new information about the software is also encouraged. This pamphlet was a supplement to the Toronto RASC Member's Night meeting of January 11, 1991. I wish to thank the following persons who made presentations, and contributed written material: Dr. James Bacon, Bill Crutwell, Mike Daly, Bob Kirouac, Paul Markov, Ted Molczan, Stephen Phillips and Terry Smith. A special note of thanks to Ted Molczan who served as editor for this handout. We also wish to thank the Toronto Centre of the Royal Astronomical Society of Canada, which funded the cost of printing, and the McLaughlin Planetarium, which provided the auditorium and AV facilities for this special meeting. A very special note of thanks should also go out to the hearty people who braved the worst storm of last winter to attend this presentation. David Aylsworth. Computers In Astronomy From the beginnings of astronomy as a science until the mid-twentieth century, it was possible for amateurs with the right background in mathematics and physics, and access to a telescope, to maintain their level of knowledge and research at a par with their professional counterparts. The advent of the computer created an ever widening chasm the amateur could not easily breach. The computers of the early 1950's were huge, very expensive and difficult to program. As a result, they were only to be found at universities and other professional research facilities -- totally out of the reach of amateurs. In the early 1970's technological advances brought about the first home computers. They were slow, could hold only very small programs and remained rather difficult to program, so they were mainly of interest to electronics hobbyists. By the early 1980's the cost and performance of personal computers had improved sufficiently for them to be recognized as serious computing tools, and many thousands were purchased for home use. The door was now open for amateurs to pursue their hobby in new and exciting ways. The breach between professional and amateur began to close! Now it was possible for amateurs to reduce data and model physical systems with a speed and precision that was heretofore unknown. Initially, it was necessary for amateurs to do their own programming, which required a background in computer and physical sciences. Before long, however, some of the more skilled programmers began to market their programs, which made amateur astronomical computing accessible to anyone with a computer. Today, the popular astronomy magazines carry numerous ads for a wide variety of astronomical software, ranging from planetarium programs to image enhancement software for CCD's (charge coupled devices). Most of the software that is available commercially produces a graphical output that enables the user to view a map or image of a celestial event. These software packages are available for most of the major computer operating environments. Some of these programs are geared to producing "pretty images" with little concern to the specific accuracy of a represented image. Others are more oriented to the generation of detailed ephemerides which are of more use to the observational amateur astronomer than the armchair astronomer. There are those who are applying computers to more advanced applications such as prediction and modelling, or data acquisition and reduction who might not be well served by the commercial software that is available and therefore must write their own programs. These people are best able to tailor their software to their special needs. For those who wish to attempt writing their own programs or modifying existing software there are a variety of books available that give the aspiring programmer some direction into this area. Also, Sky and Telescope magazine runs a monthly column called "Astronomical Computing" where the reader is treated to a program that investigates some field of astronomy. Another periodical, Celestial Computing by David Eagle, devotes itself to investigations in celestial mechanics. It is geared to those who are more mathematically adventurous, but does include complete software on diskettes, for those who are not. Computer bulletin boards are another valuable source of software for those with computers that are equipped with a modem. Bulletin boards also offer the ability to participate in conferences on all aspects of astronomy. Hopefully, the overview that we have presented will give all of you some appreciation for the role that computers are playing in astronomy as it pertains to amateurs. Software Reviews Regardless of the amateur's application, there is a large selection of software available. Whether its from a commercial source or downloaded from a Shareware bulletin board the value of these programs is something that only the end user can assess fairly. We will try not to be too critical in our assessment of the software presented here, except where warranted by the poor quality of the product itself. We leave it to the end users to determine the individual merits of the products. Sky Globe As an example of some of the low end astronomy programs that are available from the Shareware library, I selected Sky Globe. It is a package that can be both useful and fun as well as educational. Its simplicity is one of the most attractive things about it. With only a few keystrokes it is possible to see the night sky, complete with stars, planets and Messier objects. For $15.00 US you can't go too wrong. This little gem will allow you to see the sky from many northern or southern hemisphere locations. All of this is possible on the most elementary of IBM compatibles, and it can be run right off one low density floppy disk. Altogether it is a tidy little program. Deep Space 3D This software is very easy to use and would be a welcome addition to the repertoire of any observer. It is fast and gives clear, well proportioned maps in five projections. Among the best features of DS3D is the comet listings. This will generate a comet apparition quickly and give you a hard copy or computer file of the ephemeris, as well as plotting the path on a map. You can save specific maps as files and call them up whenever you like. Having the ability to scale the maps in any of the five projections is an advantage. Selecting an area of the sky for viewing can be done by designating a specific constellation or a centre point for the area you wish to be displayed. The printed maps are great tools that can easily be used at the eyepiece. As the "3D" part of the name suggests there is also a facility to show star images in 3D with a viewer that you get when you register and pay the $59.00 US fee. You can also update the comet files and add objects by entering the orbital elements that are printed in Sky and Telescope. The projections of the comets on the screen and in printouts will also show the direction of the tails and the relative angular separation from the sun. All in all, this is one of the easiest programs to install and operate. There is an extensive help file that is easy to access and it gives clear and direct instructions on how to get the most out of the software. For the uninitiated this can also be a useful tool for learning the sky. Though it does not show any deep sky objects is does show the planets (all nine of them). If the novice also wants to have some fun he or she may want to follow some of the suggestions offered in the help files to get a sense of the movement of objects in our solar system. My rating of DS3D is "best of show"! Useful, easy to use and fun. Superstar Version 3.15 When I first saw the ad in Sky & Telescope, I thought that it would be great to have a planetarium program that showed all of the SAO catalog and the entire collection of NGC and IC objects. It seemed at the time that having everything under one roof, so to speak, would be ideal. Little did I know that things are not always what they seem. As shipped, the version of Superstar that I received was not complete. The installation utility that was supposed to put everything in operational order on my hard drive did not do it. After several days of pondering the problem of the one missing file that was stopping up the works, I found it, errantly stored in another archive file. After putting this file in place the program ran flawlessly until the first time I entered spurious data. It locked up the entire system and refused let me exit the system. This is a problem which still occurs to this day. The features that were touted by the ad, were for the most part in place and were everything that had been promised and more. On a monochrome monitor, Superstar looks like just another astronomy program and has its problems with some of the planetary images. Problems which exist up to the most recent update. With an EGA or VGA monitor the software does begin to shine. The stellar images are crisp and with the bright star catalogues screen generation is fast. When going to the SAO catalog the speed of generation lengthens in direct proportion to the magnitude setting that is chosen. As another note on speed, this program was developed on a 386 class of computer and though it will run on an XT, only those with patience and a math coprocessor would want to do so for long. A minimum hardware requirement of a 286 with a coprocessor would be prudent to attempt the more advanced features of this program. The manual provided with my copy of Superstar was from an older edition and doesn't reflect the features of the program correctly. The wording of the manual is ambiguous and unclear. All in all, an object lesson in why the author of the software should never write the manual too. After a few phone calls to California, to clarify some of my questions about the software, I found that the program was indeed a treasure to work with. The supplementary SAO catalog with the proper motions was worth the money. Regular updates of the software have appeared, and author David Wright responds to calls or letters, showing that he is interested in giving support to those who have purchased the product. With numerical integration, a healthy database of variable stars, comets, and asteroids this software is well equipped to give the user months and months of projects that will fill to overflowing those cloudy days and nights that prevent other kinds of astronomy to take place. In addition to this you can add scanned images to the database, generate light curves, simulate occultations, transits and trace the motions of planets, asteroids, or comets on time scales ranging from minutes to years. Superstar v 3.15 has been well worth the $350 cost, and in spite of the difficulties I would recommend it to anyone interested in the serious pursuit of more advanced aspects of astronomy. Voyager The first time I visited the McLaughlin Planetarium, I brought home a star finder to help identify stars in the night sky. At first glance, Voyager might seem to be a computerized descendant of that simple finder, but its really more closely related to the planetarium than it is to that cardboard disk. Members with access to a Macintosh computer (with one meg of RAM) are in for a treat with this program. Voyager allows you to display the sky as it would appear at any time or date, from any location on the Earth. The display includes 14,000 objects including 9100 stars magnitude 8 or better (from the Yale Bright Star Catalog), the planets, the larger asteroids, about 3000 deep sky objects magnitude 16 or better (all visible in an 8" scope), 88 constellations and many asterisms, the Messier objects, 160 variable and 1600 binary stars. All with a resolution of one minute of time and angle. Refraction near the horizon is compensated for. Precession is calculated automatically or manually for dates 1000 BC to 4000 AD. Further, the observers location doesn't have to be on the Earth at all. You can view from the moon, the Sun, or any planet or any point in space within 100 astronomical units. You can go to a point above Jupiter and watch its moons rotate from above, or ride one of the Trojan asteroids around in its orbit. You can view the solar neighbourhood from 50 light years away and rotate the display in the X or Y axis. This feature allows the viewer to experience the three dimensional relationship between the Sun and its neighbours. Pointing at any object will open a dialog box detailing relevant information like rise and set times, RA & Dec, size, radial velocity, magnitude, stellar type, and so on. Objects can be found and displayed by typing the name. "M51" or "Whirlpool" will find the Supergiant spiral NGC 5194 and centre it on the screen. New objects, Comet Levy for instance, can be added to the database by entering the orbital elements. Comets grow tails as they enter the inner solar system! The constellations can be shown or not, with or without names. You can zoom in on objects to get a closer view; as close as one minute across the screen. You can print the display on an ImageWriter or LaserWriter at any time. Or you can save the display as a MacPaint document that you can edit. The display can be rotated in real time or in steps from one minute to four years. An ephemeris of the positions of selected planets can be generated. Eclipses, conjunctions, and occultations can be predicted for any pair of objects. Planetary magnitudes and angular sizes for a given year can be displayed on a graph and printed. The planetary positions for a particular date can be tabulated showing RA, Dec, rise, transit & set times. At a recent computer trade show, Voyager was interfaced to a large Schmidt reflector. When an object on the screen was clicked on, the telescope moved to the coordinates of the target. With the proper hardware interface the Voyager database could serve as the foundation of an automated observatory. If you're interested in astronomy, or if you want to interest someone else in astronomy, this is the program. For approximately $160 Cdn it will never replace the experience of shivering in the dark under a sky full of stars, nor will it match the sheer wonder of a real planetarium, but, it delivers an incredible amount of astronomical information. The only thing missing is the clouds. If there's anything else you could possibly want, it probably does that too. Computers, Astronomy and James Bacon I use my computer to plan my Messier object observing sessions. The major software used here is the INTERACTIVE COMPUTER EPHEMERIS (ICE) produced by the United States Naval Observatory (USNO). I use this program to find all the evenings in a given month when the two hour period beginning at the end of astronomical twilight is moon free. I also use it to find all the mornings when the two hour period ending at the beginning of astronomical twilight is moon free. ICE is also used to find the sidereal time at the beginning of the two hour period, telling me which Messier objects are on the meridian. During the recent apparition of Mars, ICE was used to find the central meridian of Mars. I also use my computer to plan my planetary observing throughout the year. ICE and VISIBLE UNIVERSE are used to find the times when each planet is 10 or more degrees above the horizon during the period between the end of nautical twilight in the evening and the beginning of nautical twilight in the morning. These times, which I call "window" times, are given for 30 day intervals in Target, the newsletter which I publish and Perceptor distributes. Knowing when the window for Jupiter is "open" is useful in planning observations of the Great Red Spot or eclipses of the Galilean satellites. The Oct-Nov/90 issue of Target explains how this is done. Target is produced using FIRST PUBLISHER, and an example of it can be found on the last page of this handout. I hope it will be useful to you! CCD's for Amateur Astronomers Amateur astronomers who have a personal computer can benefit from the use of CCD's. CCD's are extremely sensitive to light, enabling images of very faint objects. CCD images can be enhanced through the use of computer software, something that can not be done with film negatives. The relative ease of use that is possible some of this technology brings digital image processing within the capabilities of the amateur. Good quality CCD's for the amateur market remain rather expensive. Beware of low priced equipment, which may produce poor results. I use the following equipment. A Meade 10 inch Schmidt Cassegrain, Lynxx PC Plus CCD, Sanyo Computer (IBM PC compatible), Aamazing VGA Monitor (1024 lines x 768 pixels), Roland Raven Dot Matrix Printer and Catenary Systems' Zip image processor. Computer Bulletin Board Systems Computer bulletin board systems (BBS's) are yet another way to get involved in astronomy. To access BBS's you require a computer (any type) and a modem. The modem is a small piece of electronic hardware that allows your computer to talk to other computers through a common telephone line. Modems are now relatively inexpensive and are readily available at acceptable baud rates (the baud rate is the speed at which information is transmitted across the phone line). There are many BBS's available in Toronto covering a wide variety of topics. Here are three of the BBS's that will be of interest to amateur astronomers: The Health Professional's BBS The name of this BBS covers only one aspect of its content. Besides a health conference there are six others: Astronomy, amateur radio, education and science, desktop publishing, computers, and environment. There are over 60 bulletins in the astronomy conference alone, including a list of Toronto Centre meetings, the Exchange, astrophotography and telescope making workshops, observing tips, space shuttle, and Hubble Space Telescope bulletins. There are well over 50 public domain astronomy programs and files (mostly MS-DOS, some MAC) that will plot star charts, do various astronomical calculations, catalogue all the NGC objects, and more. All of these files are available for downloading to users (see below for certain restrictions). But most important is the message area of the Astronomy conference; there are hundreds of messages covering every aspect of astronomy mostly left by Toronto Centre members. Note that there are several Toronto Centre Executives and Councillors using this BBS who are willing to answer any questions you might have about the Toronto Centre or astronomy in general. The BBS phone number is (416) 745-8236, and it operates 24 h/d. The maximum speed is 2400 baud, and the modem settings are 8N1. There are two user levels. Level 15 is free of charge and provides 20 minutes per day of time, but does not permit downloading files. Level 35 is available for a one-time donation of $15, and provides 70 min/day of time, and unlimited downloading. The Canadian Space Society BBS The Canadian Space Society BBS is a public forum for space and astronomy enthusiasts, with over one hundred active users from across North America. The message section is the main area of activity on the BBS. There, you will often find discussions of the important space related issues of the day, and reports on current events, such as space shuttle missions. CSS BBS users are often much faster than the mass media in reporting news! The file section contains regular reports on the status of the various deep space probes, such as Magellan, Galileo and Ulysses. Also, there are Hubble Space Telescope reports, weekly NASA news reports, and periodic reports on activities at Cape Canaveral. One of the most popular activities supported by the BBS, is satellite observation, due to the efforts of Toronto Centre member Ted Molczan and fellow hobbyists. There are weekly uploads of orbital elements for hundreds of satellites, including the Soviet space station Mir. Also, several programs are available which enable users to make their own predictions of satellite passes. The CSS BBS is a free service, operating 24 h/d, at (416) 458-5907. The maximum speed is 2400 baud, and the modem settings are 8N1. Networked Bulletin Board Systems The networking of bulletin board systems provides the BBS users with the ability to communicate with other BBS users over a wide geographic area. Many networks, accessible through Rose Media, Canada Remote Systems and other BBS's cover most of the world. Both Rose and CRS connect to multiple networks. Some, such as NorthAmerinet or Hyperlink, are made up of commercial and hobbyist BBS's that want to provide their members with access to larger numbers of users. They share the cost of sending messages around the world, resulting in low-cost messaging and the ability of one user to tap an extensive resource. If you have a question about an obscure aspect of astronomy, the odds are good that someone on one of the networks can answer it. Other special purpose networks are beginning to be made available to the general public. Among them in Usenet, now available through both Rose and CRS. This is a network of computer systems used in government, industry and the academic world. This network allows you to get up-to-date messages about, say, the activities being performed by NASA in the space program. You can directly contact many persons who make their living from astronomy. In browsing their Sci.Astro newsgroup, it is not uncommon to see messages from the top of Kitt Peak, the Canada France Hawaii Telescope on Mauna Kea or RASC members like Rolf Meier (Ottawa Centre) or Ted Molczan (Toronto Centre). This makes for fascinating reading for the amateur astronomer; the messages are fact (and rumour) filled and more timely and complete than the reports in the press. If you do get access to this network, do not abuse the privilege. Its object is business and research, not recreation. Rose Media BBS Rose Media has the distinction of being the largest capacity BBS in North America, with 15 gigabytes of software and data on line. This is a general interest BBS, so expect to find many utilities that will help you get the most from your computer. There is also a large selection of astronomical and space oriented software and data. Most of the software on the BBS is Shareware, which means that it can be downloaded and used without charge, however users are strongly encouraged to send a small contribution to the author. Rose Media is a commercial BBS. The $70 annual fee (plus GST) provides 70 minutes per day of time, and 1.5 megabytes per day of file downloading. The phone number is (416) 733-2285, and there are 50 lines. The maximum speed is 14400 baud, and the modem settings are 8N1. Canada Remote Systems (CRS) CRS is one of the largest computer bulletin board systems in the world. Its several thousand members can access gigabytes of computer programs and data files and communicate with other members through almost 1800 different conferences and newsgroups. These conferences are connected to several international networks, putting the membership in touch with all of North America and much of the rest of the world. Of particular note to astronomy and space enthusiasts are the numerous conferences related specifically to their interests. Among them are: Conference Number Name Network 188 Astronomy Intelec 384 Space Hyperlink 547 Astronomy Relaynet 857 Sci.Astro Usenet 886 Sci.Space Usenet 887 Sci.Space.Shuttle Usenet 1643 Space Interlink 1651 Astronomy Interlink In addition, there are many astronomy related programs and data files available. There is a demonstration phone line that can be called for a free trial. Set your modem for 8 bits, no parity, one stop bit and call (416) 629-9263. They can be reached by voice at (416) 620-1439. They have a number of membership categories. The basic one that most would be interested in costs $100.00 per year and includes a registered copy of Qmail, a very useful off-line reader. BBS Information Health Professional's BBS (416) 745-8236 8N1 $15 one time Canadian Space Society BBS (416) 458-5907 8N1 Free Rose Media BBS (416) 733-2285 8N1 $70 per yr Canada Remote Systems (416) 629-9263 8N1 $100 per yr Books for Computer Programmers Here are some of the books that appear in our library that will be useful to those of you who wish to write their own computer programs. Simple Burgess, Eric, Celestial Basic--Astronomy on your Computer; Sybex Inc. (1982) Knox, Richard, Experiments in Astronomy for Amateurs; St. Martin's Press (1976) Lawrence, J.L., Introduction to Basic Astronomy with a PC; Willmann-Bell, Inc. (1989) Rogowski, Stephen J., Computers for Sea and Sky; Creative Computing Press (1982) Schroeder, W., Practical Astronomy; Werner Laurie (London) (1956) Medium Ball, John A., Algorithms for RPN Calculators; John Wiley & Sons (1978) Bouiges, Serge, Calcul Astronomique pour Amateurs; Masson (1981) Duffett-Smith, Peter, Astronomy with your Personal Computer; Cambridge University Press (1985) Duffett-Smith, Peter, Practical Astronomy with your Calculator--3rd ed.; Cambridge University Press (1988) Jones, Aubrey, Mathematical Astronomy with a Pocket Calculator; David & Charles (Publishers) Limited (1978) Mills, H.R., Positional Astronomy and Astro-Navigation Made Easy-a new approach using the Pocket Calculator; Stanley Thornes (Publishers) Ltd. (1978) Montenbruck, Oliver, Practical Ephemeris Calculations; Springer-Verlag Berlin Heidelberg (1989) Sky & Telescope, Astronomical Computing Tattersfield, D., Orbits for Amateurs with a Microcomputer--(Volume I); John Wiley & Sons (1984) Tattersfield, D., Orbits for Amateurs with a Microcomputer--(Volume II); John Wiley & Sons (1987) Advanced Bretagnon, Pierre, Planetary Programs and Tables from -4000 to +2800; Willmann-Bell, Inc. (1986) Danby, John M.A., Fundamentals of Celestial Mechanics--2nd ed.; (Willmann-Bell, Inc. (1988) Eagle, David, Celestial Computing: A Journal for Personal Computers and Celestial Mechanics (published 4 times a year) Maxey, E. Stanton, Tracking the Planets; P.130; Kilobaud Microcomputing (March 1981) Meeus, Jean, Astronomical Tables of the Sun, Moon, and Planets; Willmann-Bell, Inc. (1983) Meeus, Jean, Elements of Solar Eclipses, 1951-2200; Willmann-Bell, Inc. (1989) Van Flandern, T.C., Low-Precision Formulae for Planetary Positions; The Astrophysical Journal Supplement Series, November 1979 References Espenak, Fred, Fifty Year Canon of Solar Eclipses: 1986-2035; Sky Publishing Corporation (1987) Green, Robin M., Spherical Astronomy; Cambridge University Press (1985) Meeus, Jean, Astronomical Formulae for Calculators--2nd ed; Willmann-Bell, Inc. (1982) Meeus, Jean, Tables of Moon and Sun; Kesselberg Sterrenwacht (private observatory) Kessel-Lo, Belgium (1962) Muche, Hermann and Meeus, Jean, Canon of Solar Eclipses -2003 to +2526--2nd ed; Nautical Almanac Offices, Explanatory Supplement to the Astronomical Ephemeris and Nautical Almanac (1961) Nautical Almanac Offices, Improved Lunar Ephemeris 1952-1959; (1954) Sidgwick, J.B., Observational Astronomy for Amateurs--4th ed.; Pelham Books (1982) Smart, W.M., Textbook on Spherical Astronomy--6th ed.; Cambridge University Press (1977)