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Including ECU, Megastar and SkyMap Pro 5
Left to right: Photo of the tail of Scorpio, Norton's, Sky Atlas 2000.0, Skyglobe and Megastar Click on any of the above pictures for an enlarged view - return by right clicking the mouse The scanned charts from Norton's Star Atlas and Sky Atlas 2000.0 are produced here at reduced resolution in order to limit file sizes and down-load time.
Norton's Star Atlas
Sky Atlas 2000.0
Skyglobe version 2.0 for Windows By right clicking the mouse, you can display any of the Messier objects and some of the New General Catalogue (NGC) objects that you have previously saved as gif files. The main limitation is the small number of NGC objects displayed on screen. Considering this is a fairly simple planetarium style program (rather than a serious star atlas) then this limited display is quite OK. An additional feature is the speed of the program, the small file size that can be used (minimum installation about 2MB) and the fact it doesn't clutter up your Windows directory with dll files! Anyone looking for a copy of Skyglobe for Windows should try writing to KlassM Software, P O Box 1067, Ann Arbor MI 48106 USA or by telephoning 1-800 968-4994 (orders only), fax (313) 426-5533. I have tried to e-mail Klassm (without success) and haven't seen any new products. I apologize in advance if you get no results from the above address!
Megastar ver 3 for Windows Megastar is at its best when used in conjunction with a telescope, or to print out charts for use with a telescope. Not having used 'The Sky' for Windows (only an early DOS version), I wouldn't like to comment on how it compares with Megastar. The program is supplied with 220MB of data on CD-ROM and a single floppy disk containing the program itself. Regular updates, including comet and asteroid data, are available for down-loading at the Megastar web site. Additionally, you can add orbital details yourself if you know them. This latter procedure doesn't require file editing, you enter details directly into the program, which is as easy as it gets! One problem that seems to have crept in since the introduction of version 4 (for those of us still using version 3), is that while you can convert the comet files to ver 3 format, you seem to loose the 'detail' of the names; for example there are several comets called 'Linear' without any suffix! Another use for Megastar is plotting the track of asteroids and comets, the comet tracks sometimes shown on my 'Notes' page are produced with Megastar. Telrad 'bulls' are also a feature of this program and proved very accurate when imaging M1. It is possible to produce a rather nice set of Telrad charts for the popular deep sky objects, the colour printed charts look good.
Megastar has recently been upgraded to include a limited local horizon and also support for a Dobsonian fitted with NGC-MAX digital circles, it already had support for an LX200 interface and 'Sky Commander'. One point to consider is that Megastar is a quite large and resource hungry program, the computer in my observatory hasn't enough memory or hard disk space to run it, let alone take CCD images at the same time. Still there are plenty of users of powerful pc's out there and hardware costs are dropping monthly. Unlike ECU there is no provision to use this program as a personal database, however, on a plus side, as a sophisticated star atlas it's hard to beat and runs much quicker than ECU. A demo version of Megastar can be down-loaded from their web site. Megastar can be purchased (in the UK) from the Web Society, the cost was 97 Pounds. This is higher than ECU or SkyMap and isn't good value as not only doesn't it support NGC-MAX and similar Tangent manufactured DSC's, the author doesn't seem to reply to e-mails anymore...
Earth Centered Universe (ECU) for Windows ver 3 ECU doesn't produce such nice looking screen views as Megastar, nor is it as good at 'planetarium' views as Skyglobe for Windows. The area where it works best is when coupled to digital setting circles, you then can have a truly amazing moving star map display which I find more intuitive to use than the calculator style display of normal digital circles.. At less cost than most other similar programs and with a wider choice of DSCs than Megastar, it has to be worth considering for use with a telescope. For more information on using ECU with digital circles see my page on using digital circles Like Megastar, you can add comet and asteroid data by downloading data from a link at the ECU web site, there is also a drop down menu for editing existing data, however unlike Megastar, you have to manually edit the data file with Windows Notepad (or similar) in order to add your own new objects. I find it difficult to select a comet to view, in this respect Megastar is easier to use. Another irritation with the older version (ver 3) of ECU is the comet data file only works with a maximum of 50 objects, as the file contains many more comets than 50, you have to manually edit some of them out. Later versions cope with 400 orbits. One other area that needs care is being able to 'restore defaults' in one key stroke and loose all your customised features. The manual explains how to configure the program to use your settings as default, but we all tend to read the manual after we've fouled the programs up! One really useful feature is the built in database of deep sky objects that you can add to yourself, when you click on a deep sky object a menu appears giving brief details of the object, there are buttons displayed marked 'image' and 'notes' these allow you to view an image of the object (there are a few dozen supplied on the CD, you can add your own JPG images) and to store notes about the object. This database is really handy when using the program in an observatory. The shareware version available to down-load from their site works with DSC's, the limiting factor is the amount of data it comes with in the shareware form (700 KB). ECU costs $69.95US, shipped world wide ($59.95US, plus postage and handling, for USA orders). On the CD-ROM there are files that can be copied to a few floppy disks, this allows you to install a minimum configuration on a second computer, the space required is around 7 to 9 MB, this is handy for use with a notebook pc or a limited capacity pc such as the one in my observatory. Click here to visit the ECU web site.
SkyMap Pro 5 Chris Marriotts's SkyMap program is very comprehensive, one of it's nicest features is the ability to produce all kinds of data for solar system objects, ie sunset/sunrise tables, comet position tables and moon data tables. Clicking on any of the stars produces reams of data on the star, very useful when estimating the brightness of comets and asteroids. Chris claims the program to be one of the most accurate around, although it is painfully slow compared to Megastar. The position of Comet Linear (U5) at 19:57 UTC on 15th November 1998 computed as ra 2h 50m 42.1s, dec +60 11' 27" in Megastar, ra 2h 50m 37.0s, dec +60 11' 27" with SkyMap and ra 2h 50m 40.5s, dec +60 11' 29" with ECU. The differences aren't significant compared to the potential errors in the comet's orbital data.
Like Megastar, SkyMap doesn't support Tangent DSC's, so in my case (as the owner of an SGT-MAX) it won't be replacing ECU in the observatory. SkyMap is even worse than Megastar for taking up hard disk space, a typical installation can take 100MB. If you wanted to install the full program on a lap top without a CD-ROM drive, the Guide Star Catalogue would add a further 250MB of data (350MB in all). Most of the features of SkyMap work in the demo version, you can find a copy at the SkyMap web site. The display isn't as 'pretty' as Megastar, but the cost is a good deal less and the author responds by e-mail (very important if you are investing upwards of 50 pounds in a product). I suppose the screen views are a matter of personal taste, if a product is to be used in an observatory then a wide choice of interfaces and speed of operation may be important. For general home use a really neat and colourful screen may be more use. Or would you rather have pages of data about each object on the screen, together with the ability to produce high accuracy comet position tables? Each of the above star charting programs has it's good and bad points. Just how important these are to you depends on the use to which you put the program to. Owning copies of all three programs is probably excessive! In defence of SkyMap's computer requirements, the cost of hard drives and powerful processors are reducing all the time. The suggested minimum processor is a Pentium 133 with 16MB of ram. The program is the only one of the four that need Windows 95.
Are computer programs better than paper star charts?
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