Updated software for Guide 8.0

(2 Jun 2008) Vista bug fixed: First, I should mention that if you have problems installing Guide 8.0 (or 7.0) in Vista, you should look here for a fix.

Lawrence Harris pointed out, on the Guide user list, that in Vista, Guide will start up, but fail to draw the initial chart. You only get that chart when you force a redraw, by hitting Enter or switching to a new level or panning or some similar action. I think this problem is now fixed, but await comment. (The other known Vista issue -- toolbar buttons are shown with odd spaces between them -- remains unresolved. Here, I think Vista may reserve some extra space between menu items to allow for a checkbox. But I'm still investigating this.)

(2 Jun 2008) Better eclipse display: It's long been possible to have eclipse charts show index and time marks at user-specified time intervals. Now, eclipse charts will show such marks by default. The spacing will depend on the duration of the maximum eclipse, ranging from one second (for very short events such as occultations by small asteroids) to fifteen minutes (for occultations of an hour or less). In general, Guide will select a "good" marking scheme. One can (as has been the case for a long time now) override Guide's judgment of a good marking interval by using Settings... Mark Interval, and entering (for example) "15m" or "30s". And if one enters, for example, "i4", then every fourth mark will have a time next to it.

(2 Jun 2008) More flexible time entry: The Extras... Enter Time (now Settings... Enter Time) function has previously been picky about what formats could be entered. It is now very flexible about input, as the following examples show. The idea is that if a human can puzzle out what was meant, Guide ought to be able to do so also.

   YOUR INPUT             PROGRAM INTERPRETATION
------------------------  ----------------------
1997-May-6 12:30:23.3348   ( 6 MAY 1997 12:30:23.3348)
19970506 12:30:23.3348   * (same as above)
970506 12:30:23.3348     * (same as above)
6/18/2004                  (18 Jun 2004 00:00:00)
6.18.2004                  (same as above)
3:14.159                   (reset time to 3:14.159,  leave date alone)
13:                        (reset time to 13:00:00, leave date alone)
11/2 (or 11/f or 11 FE)    (11 Feb 00:00:00,  no change of year)
11 2 (or 11/2 or 11-2)     (same as above)
11.25 2                    (Same as above,  but 6:00:00)
11 2 -10m                  (10 Feb 23:50:00,  ten minutes prior to above)
+6d                        (advance six days from current time)
-13.4h                     (subtract 13.4 hours from current time)
-14h +36m                  (subtract 14 hours, then add 36 minutes)
Ap                         (April of current year)
Fri                        (Friday closest to current time)
Fri+2w (or fr+14d)         (Two weeks from the nearest Friday)
7.125                      (7th of current month at 3:00)
7 :                        (7th of current month, leave time unchanged)
:43:18 (or :43.3)          (43 minutes 18 seconds, hour unchanged)
JD 2451545.                ( 1 JAN 2000 12:00 )
j2451545                   (same as above)
2451545                    (same as above)
mjd 51000                  (MJD 51000 = JD 2451000.5 = 6 Jul 2008 0:00:00)
2008-03-14T15:26:53.5    * (FITS-style time: 2008 Mar 14, 15:26:53.5)
2008/50 (or 50-2008)       (50th day of 2008: 2008 Feb 19)
50 2008 3:14:15.9          (same as above, but sets time to 3:14:15.9)
50.75 2008                 (50th day of 2008,  18:00)
050.75                     (50th day of current year,  18:00)
2008 o (or Octob 2008)     ( 1 OCT 2008 00:00:00)
y1952.34                   (decimal year: about a third of the way through 1952)
1952.34                    (same as above)
nm+3                       (three days after the nearest New Moon)
-4.5w 1q                   (First Quarter nearest the time 4.5 weeks ago)
1997o6 nm +3d              (three days after the New Moon nearest 1997 Oct 6)
1997o6 +3d nm              (New Moon nearest three days after 1997 Oct 6)
now 3:00 PM                (3:00 PM today)
now 3:00 p.m.              (same)
now-1h                     (one hour ago)

Essentially, one can enter calendar-style dates; some special date formats; a day-of-year; and one can add/subtract offsets from the time.

Calendar-style input: (This is all most people will need or want to know!) You can enter a day, month, and year (or just a day and month), optionally followed by a time of day, in the order selected in the Time Format dialog (found under Settings... Formats... Time Formats). Guide will usually figure out more unusual inputs, because it can see that (for example) 1997 must be a year, not a month or a day; or that "mar" must be a month, not a day or year. With '5-1997-15', for example, the input numbers can be in any order, and Guide will still recognize that this must mean 1997 May 15. A year after 31 AD, a month name, and a day can be entered in any order, and Guide will be able to sort things out. But when given inputs such as '3 4' or '3/4/5', it checks the settings in the Time Format dialog to see if the year comes first or last, if the month comes before the day, and so on. (Except for the three cases asterisked above: these are assumed to be in year/month/day order, no matter what the Time Format dialog says.)

Months, days, years can be separated by -, /, .,or space. Hours, min, seconds can be separated by : only.

Month names are interpreted "logically". For example, at least in English, 'f' is unambiguously February (no other month starts with F) and will be recognized as such, but 'ju' could be either June or July. In such cases, the program will choose the first possible month, so 'j'=January, 'JU'=June, 'Jul'=July. 'Febru' or 'f' or 'FEB' or 'february' would all be understood to mean February.

If a time (hours:minutes or hours:minutes:seconds) follows a date, it's used; otherwise, 0:00 is assumed. If just a ':' follows a date, the time is left unchanged. The day can include a decimal portion (as some of the above examples do).

Some special ways to input a calendar-style date: You can enter just a month name (as shown above) or just a number. The interpretation of that number will be:

One or two digits:   Reset day and decimal part of day of month
Three digits:        Reset day of year
Four or five digits: Reset year
Six-digit number:    YYMMDD.  If the year is less than 40,  it's assumed to
                     be a 21th-century year (2000 is added).  Otherwise,
                     it's assumed to be a 20th-century year (1900 is added).
Seven digts:         Julian Day
Eight-digit number:  YYYYMMDD 

So one can just enter '3', for example, to reset to the third of the current month; or '2005' to get 1 January 2005; or '2451545' to get JD 2451545 = 1.5 January 2000. If a year entered in this manner has a decimal part, you'll get that fractional part of a year added. But if you want to set the year -23300 or 130000, you'll need to use 'y-23300' or 'y130000'; for a JD before 1000000 or after 9999999, you'd need to use 'j' or 'jd' followed by the JD. Decimal parts of a day can be added, so that '030913.75' is equivalent to '030913 18:' is equivalent to '2003 Sep 13 18:00:00'.

To get the output you want, you may need to add leading zeroes. If you wanted the fiftieth day of the current year, for example, you'd use '050', because '50' would get you the fiftieth day of the current month (i.e., most of the way into the next month). '0050' would get you the year 50, '00501007' Oct 7 of that year, and so on.

"Now" and lunar phases: You can enter 'now', optionally followed by a time of day and/or time offsets of the type described below. 'nm', '1q', 'fm', or '3q' will be interpreted as meaning New Moon, First Quarter, Full Moon, or Third Quarter. (Be warned that the phase times are accurate to only about an hour.) As shown above, these can all be combined in fairly logical ways.

Day-of-year input: As shown above, three digits (optionally followed by a decimal portion) will be interpreted as setting that day of the year. Also, if you enter two numbers, both greater than 31, the program assumes they are the year and day of the year (thus the "2008/50" and "50 2008" examples above). The program assumes that the larger number is the year.

Adding/subtracting an offset from the time: A '+' or '-' followed by a number will add/subtract that number of days to the current time. One can add a letter specifying time units: 'd' (day), 'h' (hour), 'm' (minute), 's' (seconds), 'w' (weeks), 'l' (lunations), 'y' (years), 'c' (centuries). Some examples are shown above.

This can be useful in dealing with time zones. For example, if your default time zone is UT, but you want to enter an Eastern US (UT-5) time, you can just add '-5h' to it.

You can add more than one offset; for example, Fri+2w -5h would mean "two weeks from the nearest Friday, midnight Eastern US time."

If you've checked the "two-digit years" box in the Time Format dialog, then you can optionally enter a year between 1940 and 2039 with just the last two digits. Be warned that in this case, it becomes much more important that you have the year, month, and day in the order specified in the Time Format dialog, because Guide won't be able to automatically determine if (for example) "01 02 03" means 2001 Feb 3, 2001 Mar 2, 2002 Jan 3, 2002 Mar 1, 2003 Jan 2, or 2003 Feb 1. It is for this reason that I'd suggest continuing to input years with four digits and month names as text.

Some other forms will be interpreted, but if there's ambiguity, you may not get what you wanted.

The current calendar will be used (almost always the Gregorian or Julian, but read on). If you select, say, the French Republican calendar in the Time Format dialog, an entry such as 11-2-216 will be interpreted as 11 Brumaire 216. Perhaps more importantly, if you've selected the Gregorian/Julian mixed-mode calendar, dates entered will be assumed to be Gregorian after 14 Oct 1582 and Julian before that, fixing a minor bug.

To be added: it would be nice if one could add 'UT' or 'EST' or 'LST' or 'UT-8' or similar time zone abbreviations to any of the above entries. Much less significantly, being able to add 'AH' (Islamic calendar), 'greg', 'julian', 'AM' (Hebrew), or similar calendar indicator would be nice.

(2 Jun 2008) New "asteroid options" dialog/some menu rearrangement: Guide's menu structure has become a mess. Many things have been added over the years, and it's well past time for it to be arranged more logically. As a start, I've moved "Enter Time" from the Extras menu to the Settings menu, right under "Time Box". And all of the asteroid/comet related options have been put into a single "asteroid options" dialog, accessed from the Extras menu. This includes the controls for adding MPC comets/asteroids, editing orbital elements, and setting the line of variation.

Eventually, this dialog should also contain controls over asteroid filtering and a way to set the path to the MPCORB file.

Further thoughts on what the menu layout should be are welcome. I'm quite good at adding features to Guide. Arranging them so people can actually find them... well, I'm not always so good at that!

(2 Jun 2008) Fixes/improvements to MPCORB handling: The MPCORB database of asteroid orbital elements underwent two small format changes in quick succession. These caused Guide to be unable to label asteroids by name (you could still get them to show numbers or provisional designations), and Guide couldn't find asteroids by their names. This is fixed.

Also, the way Guide displays asteroids from MPCORB has been considerably improved, as follows: Previously, Guide would have a long pause once when drawing asteroids from MPCORB, to compute some data covering that particular day. It could then draw asteroids briskly within that day, but if you changed the time to go outside that range, you got another long pause.

Now, that has been increased to a fifty-day range. Many people are only interested in what's happening in the range "a few days ago to a few days from now"; those people won't see those long pauses as often as was once the case. Further improvements are in the works.

(2 Jun 2008) Fixes to artificial satellites: Jari Suomela and Masaki Kouda pointed out that the lists of artificial satellite passes, shown when you click for "More Info" on a satellite or use the "Tables... List Satellite Passes" function, had some problems: at times, no passes would be listed when many should have been found. Also, you should be able to click on the dates/times shown for rising, setting, and entering/leaving the earth's shadow; that function was misbehaving, too, if there were other objects in the TLE with the same name. (Jari Suomela ran into this first: since the Chinese antisatellite missile test, there are now hundreds of objects with the name FENGYUN 1C DEB.). These problems are fixed.

Also, Jari noticed that frequently, the "maximum altitude" above the horizon listed in a table of satellite passes was not, in fact, the maximum altitude. This is fixed.

(2 Jun 2008) Improvements to artificial satellites: In the course of investigating the artificial satellite problems mentioned above, Jari mentioned that it would be nice if artificial satellites could be labelled, not just by name, but by NORAD number or COSPAR ("international") designation. (NORAD numbers assign to each satellite a five-digit number ranging from 00005 to, at present, about 31300. COSPAR designations are five digits plus one to three letters, such as "67035B": part "B" of the 35th launch of 1967.)

You can now click on an artificial satellite, then on Display, then on Options, and see three radio buttons to label satellites by name, NORAD number, or COSPAR/international designation. There is also a button to bring up the TLE selection dialog.

Also, you can now find satellites (in Go To... Object Name, or Go To... Satellite) by entering a five-digit NORAD number followed by a 'U' (or 'u'). Or you can enter the international (COSPAR) identifier, in forms such as '1969-046F', '69046F', or '69-46F'.

(2 Jun 2008) Use of Guide in Linux, using Wine: Some users have reported success in the past in using Guide in Linux, with the Wine package. (Wine stands for Windows Is Not Emulated; it allows one to run many Windows programs from within Linux, by replacing the Windows API. Since it is not an emulator, the speed is supposed to be about as good as "real" Windows. I don't know if this is true in general, but it appears to be the case for Guide.)

I had difficulties doing this in the past, but recently puzzled out how it can be done. There are at least four issues:

First, you have to run the Setup program using Wine. It's probably best to use the new Setup program. The old one is based on 16-bit code, and could give Wine some trouble.

Second, after installation, you must rename the file STARTUP.MAR to startup.mar. In Windows, the uppercase name wasn't a problem; in Linux, it is a problem. I expect there may be other problems resembling this that I've not discovered yet.

Third, if you start Guide from a console, some Wine debugging data will be shown there: mostly complaints about calls to a Windows heap compacting function that isn't implemented in Wine. This is essentially a cosmetic problem, but you can suppress it by hitting Alt-J and entering Wine=y. Once Guide "realizes" it is running under Wine, it won't attempt to use that function and the messages will go away.

Fourth, I'd suggest going into Display... Star Display (you can also get there by clicking on the magnitude part of the legend area) and turning Bayer (Greek) letters off. They appear as garbage, at least on my screen. (Note: Stephen Tonkin has posted a fix to enable Greek-letter display when running Guide under Wine. You can get the required symbol.ttf file from your Windows partition, or download it freely from any of several sites; here is one site offering symbol.ttf, and Googling 'symbol.ttf' will find dozens more. Steve has since commented that in Ubuntu 9.04 (Jaunty), he had to copy symbol.ttf to /usr/share/wine/fonts/symbol.ttf.)

Also, the default font is a bit odd; you should probably go into Display... Screen Font and change it.

You will probably find that you can't download star data or DSS images, and that the automatic downloading of satellite and comet elements fails. All this is due to a missing DLL, 'mfc42.dll'. This can be fixed by using Winetricks and using it to install that DLL in Wine. (I gather that it actually wouldn't be all that difficult to install anyway, but Winetricks makes it absurdly simple.)

Please note that I have not done a great deal of testing of Guide in Linux yet! There are probably many remaining issues. Basic display of charts appears to work without difficulty. I've had one lockup, of unidentified origin. I will investigate any issues, though I must admit that this isn't a high priority.

Please also note that I started this testing in early 2008. In mid-June, Wine 1.0 was finally released (after about a decade!). It appears that this version resolves all sorts of issues people were seeing in assorted Windows applications, and may fix any problems with Guide in Wine. (I'm not sure if the lack of problems means that Guide in Wine is very stable, or if it means not many people are trying it out!)

(2 Jun 2008) More VizieR catalog(ue) downloads, and ability to add your own: Guide has been able to access certain star catalogs via the Internet for some time now (under Extras... Get Star Catalog Data). These have been limited to GSC-2.2, USNO-B1.0, CMC-14, USNO-A2.0, 2MASS, and UCAC-2, with no provision for adding your own catalogs.

The VizieR service offers access to hundreds of catalogs. A few are obsolete and some have a limited audience, but many are of at least some interest to some Guide users. It's now possible to add access to any of these.

As examples, the current update includes support for four new downloadable catalogues: the Veron/Veron-Cetty 12th Catalog of quasars (an improvement to the 10th Catalog provided with the Guide CDs), the NOMAD combined star catalog (a merger of B1.0, UCAC-2, and Tycho), GSC-2.3 (a slight improvement over GSC-2.2), and SDSS-5 (the fifth release of the Sloan Digital Sky Survey).

If you go into the Settings... Toolbar dialog, you'll see toolbar buttons for all four options near the bottom of the list. You can then toggle on the buttons, and/or assign hotkeys for them. Downloading data from these catalogues then takes place just as would be the case for the other catalogs listed in Extras... Get Star Catalog Data. You can click on the objects in question, get 'more info' about them, and so forth.

(2 Jun 2008) Display and entry of apparent coordinates: If you go into Settings... Formats (or right-click on the epoch shown in the Legend area), you will see that in addition to being able to show and enter RA/dec coordinates in J2000, B1950, mean coordinates of date, and user-specified epochs, you can ask for apparent coordinates of date. These essentially resemble mean coordinates, except that the effects of nutation and aberration of light are taken into account.

Select apparent coordinates, and the RA/decs shown in the legend and help system and elsewhere in Guide will (unless otherwise specified) all be in apparent coordinates of date. Also, you will be able to enter apparent coordinates in the Enter RA/Dec dialog.

(2 Jun 2008) Use of apparent coordinates in scope control: I had an inquiry from a Guide user who noted that Guide sends, and expects to receive, mean coordinates of date when controlling a scope. He asked if this could be overridden to allow use of apparent coordinates instead. (Apparent coordinates are mean coordinates with the effects of nutation and aberration added in. This can result in a difference of about a half arcminute.)

I replied that I'd used mean coordinates because at one time, a scope accurate to a half arcminute was almost inconceivable. Also, I think (but am not completely certain) that the Meade scopes base their alignment on mean coordinates of date, so Guide ought to follow suit. However, it wasn't a big deal to add this piece of functionality, so I have done so.

If you run Guide and hit Alt-J, you can enter the text

SCOPE_EPOCH=A 

Guide will then switch to sending (and expecting to receive) apparent coordinates of date when controlling a telescope. (This applies to all telescopes.) To switch back to mean coordinates, hit Alt-J again and enter

SCOPE_EPOCH= 

With the use of "traditional" apparent coordinates, this will allow Guide to point the scope (in theory!) to within about half an arcsecond. (At that point, the effects of polar motion and topocentric aberration will have to be handled.)

All this is an extension to a not-very-well-documented feature: some years back, I was asked to set up Guide so J2000 coordinates could be used in telescope control. (The gentleman asking about this had a "home-brew" system that ran on a J2000 basis.) One can do this in Guide by hitting Alt-J and entering

SCOPE_EPOCH=2000 

Any other epoch can also be chosen. I don't know if any manufacturer has, for example, built a scope in 2006 and "hard-coded" positions for 2006 in ROM. But if this has happened, Guide can handle it with SCOPE_EPOCH=2006.

(2 Jun 2008) Better handling of interplanetary spacecraft:

Most interplanetary probes are, of course, ridiculously faint, down around mag 30 or 40 or 50. So you will probably have to turn satellites "On" if you want to see these objects at all.

(2 Jun 2008) Some minor improvements:

Shift-Right now rotates the CCD frame toward the cursor location. My thought is that I'll add two small boxes to the frame, on which one can click to drag the frame around (one small box in the center to move the frame, another at the edge to rotate it). But that'll wait until this version becomes "official".

In testing this, I found an interesting and unexpected use for this capability: my first test case was 61 Cygni. When I toggled proper motions off, the stars snapped back to their 1991.25 position in a satisfying way; but when I started animating, they moved, albeit much more slowly than they had when proper motions were enabled. I was briefly annoyed, thinking I'd added a bug; then I realized that while proper motion was no longer in effect, orbital motion was still enabled. So with proper motions shut off, one can animate binary stars and see their orbital motion without having them drift off the screen.

Now, the GRS longitude is determined using data in the file grs_lon.txt. Documentation is provided at the end of that file. Basically, it's just a list of observations of the GRS longitude at various dates; Guide interpolates within those observations. The GRS longitude is then listed in 'more info' when you click on Jupiter.

(24 Mar 2007) Ability to use ASCOM scope drivers: Quite a few telescopes can be controlled via ASCOM drivers (click here for the full list of scopes supported by ASCOM). If you run the current version of Guide and click on Settings... Scope Control, you'll see an "ASCOM" radio button. Click on the "ASCOM" radio button and on OK, and you'll be prompted to choose your telescope.

Guide will show the 'scope pad' menu item, and you can use the 'slew Guide' and 'slew scope' functions within the Scope Pad. (Thus far, the other functions, such as setting slew rates and arrow keys, don't work.) Also, the scope indicator function will work with ASCOM scopes.

To get this to work, you must download this DLL that allows Guide to communicate with ASCOM (about 62 KBytes). If you don't already have the ASCOM 'platform' of drivers set up, you should visit the ASCOM downloads page and get the current ASCOM platform and install it.

(24 Mar 2007) Ability to get CMC-14 data via Internet: In the Extras... Get Star Catalog Data menu, there's a new "Get CMC-14 from Internet" option. This works much like the existing star catalog download options, except that it gets data from the CMC-14 star catalog. This catalog provides data for over 95 million stars, covering almost all of the area between declinations -30 and +50. That makes it quite a bit denser than UCAC-2, but not nearly as dense as Ax.0 or B1.0.

The positions are about as good as those from UCAC-2 (and therefore much more accurate than those from Ax.0 or B1.0). The really interesting thing about this catalog is that the photometry (in r') is quite good. No effort was made to get good photometry in UCAC-2, so this is a very welcome change indeed.

(24 Mar 2007) Ability to find A2.0 and UCAC-2 stars by catalog number: This followed an inquiry from Josch Hambsch on the Guide user list. If you have set up Guide to read A2.0 data from the hard drive, you can now use Go To... Object Name, and enter an A2.0 designation such as

A2 1050 3141592

Guide will then center on that A2.0 star.

A2.0 designations always consist of "A2", followed by a zone designation (always a multiple of 75), followed by an object number within that zone.

If you've set up Guide to read UCAC-2 data from the hard drive, you can now use Go To... Object Name, and enter a UCAC-2.0 designation such as

U2 3141592

Guide will then center on that UCAC-2.0 star.

(24 Mar 2007) Some artificial satellite improvements: You can now use 'Go To... Object Name' and find satellites via NORAD and international designations. For the former, one would enter (for example) 'NORAD 13456' or 'norad 13456'. (The 'norad' prefix is necessary, to distinguish between satellite 13456 and minor planet 13456.) For international designations, you would enter (for example) '69046f' or '69046F', to find the object 1969-046F.

Also, the underlying ephemeris code has been revised, resulting in some small improvements in accuracy; click here for details. Be advised that nobody seems to know exactly what model is used by NORAD, so the "improvement" may be somewhat illusory.

(24 Mar 2007) More 'More Info' about artificial satellites: Paul Gabriel suggested that Guide ought to show the TLE (Two-Line Element) data for artificial satellites in 'More Info'. This data is now shown, but a "plain" TLE is hard to puzzle out (all the orbital data is run together without comments or spaces), so the data is also shown broken down so you can see the individual bits and pieces.

In addition, 'More Info' for satellites now includes links to data from Heavens-Above, n2yo.com, and the NSSDC (National Space Science Data Centre). Each link gets you additional data about the satellite in question. Heavens-Above, for example, will show you the current ground track of the object, and its orbit as "seen from above". NSSDC will give background information about the mission the satellite was intended to accomplish.

(24 Mar 2007) Proper motion arrows shown for UCAC-2 stars: Ed Wiley pointed out that in the Star Display dialogue, you can tell Guide to show arrows indicating a given amount of proper motion for stars, and those arrows will appear on Guide's "built-in" star data. But they don't appear on UCAC-2 stars (neither those shown by downloading UCAC-2 from Internet, nor those shown by displaying UCAC-2 data from CD-ROM or hard drive.) This has been fixed; proper-motion arrows will be shown for UCAC-2 stars.

(24 Mar 2007) Fix for RealSky bug: Several people noticed a problem with extracting RealSky images. The extracted images were frequently for areas far from the intended location. This has been fixed.

(24 Mar 2007) Use of new GCVS (General Catalogue of Variable Stars): This catalogue has had some improvements in recent years. Coordinates have been fixed, and new objects added. You can download the current version of the GCVS here (about 6.6 MBytes). If you put this in your Guide folder, still with the name 'iii.dat', then the Go To... Star... Variable Star function will make use of the new file. Also, when you click on a star and get "more info", the "comments from the GCVS" will be drawn from the new file.

(24 Mar 2007) Mixed "Gregorian/Julian" calendar: In the past, if you selected a date before 15 October 1582 (Gregorian) and wanted dates to be shown in the Julian calendar, you had to reset the calendar (in the Time Format dialog) to Julian. If you didn't do this, Guide would (usually) warn you that you were using the Gregorian calendar for a date before 15 October 1582. Similarly, if you attempted to use the Julian calendar for dates after the switchover, Guide would again warn you of possible trouble.

But I often get comments from people who have gotten things switched around, and are wondering why Guide's date is off by 13 days. (As soon as I hear that figure, or "a couple of weeks", I know what's going on.) To guard against this, the Time Format dialog now includes the Gregorian/Julian "calendar" as an option. Select this, and calendar dates will be shown using the Gregorian reckoning for dates on or after 15 October 1582 (Greg.), and with the Julian system for dates prior to that.

This will be the default calendar in Guide 9.0, and will (I hope) reduce the number of tech support questions I get on this subject.

One odd side effect of this: if you select the Gregorian/Julian calendar, and go into the Time dialog, and select October 1582, you'll see a calendar resembling this:

Su Mo Tu We Th Fr Sa
30  1  2  3  4 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31  1  2  3  4  5  6 

Which is correct: in that month, Thursday, 4 October was followed by Friday, 15 October, causing havoc in the computation of rents and other monthly payments (the "Y1582 problem").

(29 May 2006) Fix to deal with six-digit asteroid numbers: Some months ago, the Minor Planet Center designated the 99942nd minor planet. MPC held off on numbering more than this, because many of their files only allowed for five-digit numbers. Sort of like the two-digit numbers once used for years, causing the "Y2K Crisis". Those of us involved in astronomy software now have an "A100K Crisis".

It wasn't clear how MPC was going to resolve this issue. Turns out that the astrometry report format and the MPCORB format now fit six-digit numbers into a five-character field, using a pseudo-expanded hexadecimal system: asteroid 100000 is stored as "A0000", and asteroid 359999 will be stored as "Z9999". Then asteroid 360000 will be stored as "a0000", and asteroid 619999 will be stored as "z9999". Guide is now fixed to handle these oddities. (I think. As with the Y2K foolishness, a lot of code is affected, and I may have overlooked something; please let me know if you spot any problems!)

(In theory, we may someday face an "A620K Crisis". However, well before then, MPC hopes to switch to a new observation format which allows reporting of all sorts of additional details such as uncertainties, reference catalogues, photometry... and allows for far more numbered asteroids and other designations.)

(29 May 2006) Ability to add/modify user-specified locations: There is now a file, user_loc.txt, to which you can add your own locations. A few examples are provided. For each location, you must supply a latitude/longitude and altitude, the name of the location as entered into Guide's "Enter Location Name" dialog, and the name of the location as it will appear on Guide's title bar. Details are given in the first few lines of user_loc.txt.

At some point, I'll probably wrap some user interface around this. You should be able to set up a location with latitude/longitude, then tell Guide: "Store this location under the name 'Observatory loc'", and similarly for other locations.

(29 May 2006) New functions for controlling Meade telescopes: Almost at the end of the list of functions given in Settings... Toolbar, you'll see three new ones: "Set LX-200 time", "Set LX-200 lat/lon", and "Get LX-200 info". (Despite the "LX-200", these will actually work with all Meade telescopes.)

The first two will cause Guide to reset your telescopes' date/time and/or latitude/longitude. The latter is stored in the scope's permanent memory, so it's not terribly important. But the AutoStar (and, I assume, many other Meade scopes) lack a clock, and therefore start up ignorant of the current time. So the "Set LX-200 time" button may be of use every time you start the scope.

"Get LX-200 info" will cause Guide to inquire of the scope as to its type (AutoStar, LX-200 16-inch, etc.), date, firmware version, and so on. It will then show a dialog of this information on-screen.

Certain aspects of how to control Meade scopes are undocumented. For example, I know that my Autostar ETX gives the "Scope type" as "Autostar" (the first line given when I click on "Get LX-200 Info"). But I don't know what other "scope types" there are. Please let me know what "scope type" Guide gets for your scope!

I have a particular reason for wanting to know this. There are at least four broad categories of Meade scope: "classic" LX-200, AutoStar, 16-inch LX-200, and GPS scopes. Each has a slightly different command set. (For example, some scopes have variable focuser rates, or can "park" or turn field derotators on or off. And the GPS commands obviously will work only with the GPS scopes.) If I knew what "scope types" were out there, I could rig Guide up to detect them and show only those functions specific to your scope.

If you look near the bottom of toolbar.dat, you'll see that a whole slew of Meade functions are quite possible. If you wish, you can even move them to among the other Meade functions (focus, slew, etc.) and modify the number of toolbar buttons at the top of the file to include the new buttons.

(29 May 2006) Use of B1.0 data from the hard drive: Markus Funke suggested, in a message on the Guide user list, that Guide might support use of B1.0 data in its raw form. Not many people actually have access to that data, but it's being distributed on hard drives within Europe. Markus sent me a few megabytes of example data near the celestial poles for testing purposes.

If you run Guide, hit Alt-J, and enter a line such as

B1_PATH=d:\b1

then Guide will look for B1.0 files in that folder, in the usual B1.0 directory organization. For example, Guide would expect from the above that it would find data for the north celestial pole in the folder d:\b1\179\b1799.cat. If you look in Extras... User-Added Datasets, you'll see a new "USNO B1.0 from hard drive" dataset; you can turn this on, adjust the limiting magnitude, and change the color and labelling of the data.

(29 May 2006) Better default contrast when loading images: Guide had an annoying tendency, when loading images via the Extras... RealSky/DSS Images... Add DSS Image option, to show them as all black or all white. Getting the right contrast could be very annoying.

On loading an image, Guide now does a rough histogram and comes up with a pretty good estimate of the contrast level that ought to be used. I admit that adjusting contrast/brightness is still painful. But at least you'll now be starting from decent initial values.

(29 May 2006) Comments on NGC and IC objects from Steve Gottlieb's observations: On a post in the AmAstro group, Steve Gottlieb mentioned that he has posted an updated set of observations of deep-sky objects on the NGC-IC site. You can click here to get the list of observation files.

The observations are split over 17 files. One contains all the IC observations; the others span ranges of 500 NGC objects each. If you download these files to your Guide directory, information from them will appear when you ask for "more info" on an NGC or IC object. Many thanks to Steve Gottlieb for making these data available!

(29 May 2006) Hotkeys/toolbar buttons to increment, decrement, or round off the time: If you look in the Settings... Toolbar dialog, you will see, about a third of the way down the list, options to increase (and decrease) the time set in Guide in steps of .1 second up to a millennium, and to round off the time value. This last means you can do things such as, for example, set the time/date to 1 January of the current year, or to the first of the current month, or to the nearest hour, minute, or second. (Click here for some suggested hotkey combinations.)

(29 May 2006) Ability to adjust the time by clicking on the time shown in the legend: In the past, if you clicked on the time shown in the legend with the left mouse button, Guide would bring up the time setting dialog. Click with the right mouse button, and Guide would set the time to the present instant.

Now, you can left-click on the millennium, century, decade, year, month, day, hour, minute, or second shown in the time in the legend to increment these values. For example, if the time in the legend is 2005 Apr 3 14:15:26, you could left-click on the '5' in 2005 to go ahead to 2006, or on 'Apr' to get to May.

Right-clicking has the opposite effect, causing you to go backward in time by the same step.

If you have a three-button mouse, using the center mouse button will cause Guide to round off the time. That is, use the middle mouse button on the hours digit, and Guide will round off the time to the nearest hour. Use it on the date, and Guide will round off to 0:00:00 of that date.

Those with two-button mice can use Shift-left button to get the effect the center button would cause.

These digits don't cover the entire time shown in the legend; you can still left-click on the spaces and ':'s to get the time setting dialog, or right-click to set Guide to the current time.

(29 May 2006) Check-boxes to round off ephemerides and trails to nearest step: The 'Make an Ephemeris' and 'Add a Trail' dialogs both have a new 'Round to Nearest Step' check-box. Suppose you want to make an ephemeris or trail with a one-hour step, starting on the next hour. In the past, you would have to set Guide's date/time to that hour, then make your ephemeris or trail. If you didn't do that, you would get an ephemeris or trail starting at exactly whatever time was set in Guide.

Now, you can check the 'nearest step' box, and Guide will round off to the nearest hour (or whatever step size you happen to be using for the ephemeris or trail.) Something I really ought to have added many years ago!

(29 May 2006) Better handling of atmospheric refraction: The Settings... Location dialog now has a check-box to "include refraction". Previously, Guide didn't include refraction in its display of altitude in the legend and when you clicked on an object. Now, if you check this box, both displays will be adjusted. The temperature, altitude, barometric pressure, and relative humidity specified in the Location dialog will be used when computing refraction.

A few things to be warned about:

Alt %.3lf  Az %.3lf   []
alt {%4.1lf}  az {%6.1lf}\n

Change the '.3lf' and '.1lf's to, say, '.6lf', and the alt/az values will be shown to six decimal places. Be warned that they are in no way truly accurate to six places. Four places (meaning a precision of .36") is probably about the best for which one can hope, with poorer accuracy near the horizon.

(If you're running Guide in a language other than English, you should change the variant of strings.dat for your language.)

This confused a lot of people, and it's an item mentioned on the FAQ for current Guide users. People assumed that they should enter a level number, not the size of the level in angular measure. It was simply a bad design choice on my part. Now, when you click on that menu item, you get a dialog that shows the current sizes of all 20 levels, and you can reset them.

(29 May 2006) CCD guider chip range rings: Kevin Cooper suggested that I might borrow an idea from the program Starry Night. In this program, one can have a pair of dashed circles indicating the range of locations that could be covered by the CCD guiding chip. If you use Display... CCD Frame, and click on the "Guider range" check-box, you will see what is meant by this. (The check-box is grayed out if you aren't using a camera with a guider chip.)

Also: one could already right-click on the outline of the main CCD frame or the outline of the guider chip, and then on "Display" to get the CCD Frame dialog. One can now also click on the guider rings, in which case you get one more button: "Rotate CCD". Clicking on this will cause the CCD frame to rotate to put that point on the center of the guider chip.

For example: suppose you have turned on the guider rings, and see a particularly good guide star between them. You would right-click on one of the guider rings (either inner or outer) near that star, then on "Rotate CCD". The CCD would rotate to put the guide star within the guider chip.

(29 May 2006) Some very minor changes: Nothing of tremendous import, but I should mention them:

If you don't explicitly set a lowercase hotkey, the action for the uppercase one will be used instead.