Note: This page is a help file for Lunaria Lunar Almanac Sky Maps. It is not the main page.

     The main page is here.      site home

Introductory textbook from Univ. of MN astronomy class (Cosmic Connections) .pdf files   section two

HOW TO USE THE MAPS:

  The maps represent the sky as if you were looking up at it, which is why the compass rose seems reversed. If you would hold the sky map over your head and line up North on the map with true North, then it would match the sky for that time and date. Suppose you'd like to find a star that's shown on the map. The easiest way is to find something bright and obvious and then navigate using it as a reference. Be aware that the Moon moves much more quickly than the stars and planets, meaning that it probably won't be in the same place as the map shows unless it's the same time and date as the map is made for. Venus, Orion, and Polaris are usually good starting points. The dotted circle in the centre of the map is at 60 degrees above the horizon, and that can help you estimate how high the object you're looking for is in the sky. A fist held at arm's length is about ten degrees. The good news is that once you've found what you are looking for, it will be fairly easy to recognise the pattern of surrounding objects and find it again later. Remember that some constellations have only one or two stars visible to the naked eye unless you're in a very dark location.
  Also understand that stars rotate around the North Star (Polaris). If you are looking at the sky at a time earlier than the maps are made for, then the stars will be offset counter-clockwise. Planets, however, move differently. They move in a curved line across the sky (the ecliptic) from East to West, and this line crosses the Southern part of the sky (for the Northern hemisphere).  There are times when planets may rise and set in the North-East or North-west, but you will never see a planet in the Northern part of the sky. If you are looking at the sky earlier than the time the map is made for, a planet will be to the East of the position shown on the map.
  You can always ask me for help in finding something, but bear in mind that there is only so much I can explain without being there to point you to the object you want to view.
  I can also provide you with a black-and-white map to make printing easier. Request these (along with location, date, and time) from webmaster@theskytonight.com and I'll e-mail it to you or set up an ftp link if you need several maps.

FTP SITE:

ftp (file transfer protocol) is a system to make files available directly, rather than from a Web page. Most browsers handle ftp well. By clicking on the link to the ftp site, you will be taken to a "page" that lists the files available in the Lunaria directory. The file named "astronomy_skymap_readme.txt" contains information on how to interpret the filenames and get the specific information you want. Just click on that file, and it will be sent to you. It can be opened with a program such as WordPad or Microsoft Word, or Notepad.

Knowing this, you will be able to get the information about the sky in your area. For example, suppose that you live on the West Coast near San Francisco. You could then click on "franciscomoon.txt" to get the rising and setting times for the Moon. This would provide you with a table for a week's worth of times. If you lived in the South, you could choose between a sky map of Atlanta or New Orleans, or the data for rise/set of the moon and planets in those cities. If you wanted the morning sky map of Atlanta, clicking on "atlamorn.gif" would open up a window in your browser (most likely) showing you that map.

If you have visited the ftp site before, you might see old files listed. This is because your browser has stored (cached) the page on your last visit. Clearing your cache (Temporary Internet Files) will allow you to see the current directory. Many of these problems can be eliminated by using an ftp client. One is available at the site at ftp://ftp.visi.com/users/sirius/software

Look for ws_ftp32.zip and download it.

Remember, ftp is your friend. Rather than download the whole page to get the rise/set time for the Moon, you can get only that table through ftp, for example. Those with slower connections can also get only the maps they need, which is also better for printing purposes.

ECLIPTIC:

  The ecliptic is the path that the Moon, Sun and Planets take across the sky. While the stars rotate around Polaris (the North Star), the Moon, Sun and planets move in a curved line across the sky. This curved line (the ecliptic) also moves continuously.

  For an example of the ecliptic's rotation through the course of one night into the day go here.

You can also see the rotation of the stars through the night into the day.

EPHEMERIS:

An ephemeris is a table of astronomical data. These pages have two different tables. One is a table of rise and set times for a planet or the Moon, and the other includes the time for End of Civil Twilight (ECT). Sunset is not automatically dark; there is a transition period to darkness. This is what End of Civil Twilight is -- when darkness actually falls and stars, etc. are visible to the naked eye. Of course, the Moon can be seen even in full daylight, and Venus is sometimes bright enough to be seen in what is technically called daylight. You can use ECT along with the rise/set times to tell when or if a planet is truly visible. For example, if ECT is 16:32 and Jupiter sets 17:04, then Jupiter will be briefly visible low in the west just after dark. If Saturn rises 01:35 and Civil Twilight Begin (CTB) is 06:00, then you have about four hours in the early morning to view Saturn. Using ECT and CTB gives a degree of flexibility, since the maps are only produced for one time during the morning and evening.

An ephemeris is generated weekly for Venus (including ECT). Other planets are included if they are visible. So, one week you may see an ephemeris for Mercury, and the next week it may be replaced by one for Mars. Phase is included for Venus in terms of a percentage. For example, a phase of .892 means Venus would be 89.2% full. Phase percentages are also included for the Moon.

  One feature that may be included is "transit time", which is the time the planet is the highest in the sky and exactly South. Transit time is only included when the planet is visible at transit, and may not be shown for all planets. If the transit time is listed for a planet, you have a very good chance of seeing that planet. You would be looking directly South when viewing a planet at transit time, or in other words, directly opposite Polaris. In fact, using the transit time and Polaris you can judge the location of the planet whenever it might be visible. If you are viewing before transit, then the planet will be to the East of due South. Since Vega, Capella and Deneb never set, they can be used as convenient reference points for a planet shown on the map. For morning viewers, the "Civil Twilight Begins"(CTB) time is included, which is the end of stargazing for the previous day. Magnitude ("Mag") is the brightness of the planet. The lower the number, the brighter the object. In most suburban or urban areas, the dimmest stars you will be able to see are around 3.2 in magnitude.  These figures are included to help you find a planet in the sky, and to find the best time to view it.

  Ephemeris data is provided in Local Mean Time (LMT), meaning it is adjusted for your location. The sky does not correspond to the artificial time zones we have created. Within the same time zone, the Sun will be highest in the sky (Noon) at different times depending on location. 

All tables now can be found on the ftp site. There are links to each ephemeris on the city's page and also on the ftp site. Some additional data may be found on the ftp site that's not found on the web site.

STAR NAMES:

  The names of some stars may be different than those you are familiar with. This is because the SkyMap software is published in Britain, and Europeans have a different naming convention. Only a few of the brightest stars are labelled on the maps found on my site. This is because the names would block out what you actually want to see, and because the names of the brightest stars are identical to the European names. The labelled stars will serve as reference points, however, for a standard seasonal or hemispheric star map. Links are provided to more detailed sky maps in other sites, if this is where your interest lies. See the home site towards the bottom of the page for these links.

MINOR PLANETS:

  Uranus and Neptune are not visible with the naked eye, but a decent pair of binoculars will allow you to view them, however dimly. This site is primarily geared to naked-eye viewing, but these two planets are shown on the maps for those who might wish to follow them. No weekly data is generated for them, however. Pluto is visible only with a quality telescope. You may request an ephemeris for a minor planet from webmaster@theskytonight.com, and please let me know the dates you are interested in. I'll be happy to work one up for you.

CONSTELLATIONS:

  Because constellations are so large and would involve showing many, many more stars on the relatively small maps here, they are not presented weekly on this site. Links are provided to sites that do this kind of thing very well. On this site, once a month a basic map of constellations will be published for each city, and these can be used along with the current sky map to locate a particular constellation in the sky.  See the ftp site, the access site, or the page for the particular city for these maps.
  Constellations can be discouraging to locate. Try the easy ones first, like Orion, the Big Dipper, and Cassiopeia. Once you become familiar with these, it gives you reference points to the others. Some constellations have dim stars that might not be visible in city or suburban situations.

This is a handy reference for locating some major stars and constellations:

EQUIPMENT

  What equipment do you need to enjoy the night sky? None at all, really. A pair of binoculars is useful for dimmer stars, comets or close views of the Moon, but avoid the smaller types. These have a narrow field of vision that makes it difficult to see the "big picture" necessary to find an object. Something like a 7X50 is ideal.

  A planisphere is a sky map that can be adjusted to the date and time, showing the current stars and constellations. Usually it takes the form of a moveable disc with an oval window. Make sure the planisphere is designed for your part of the country. Some are designed for 50 degrees latitude and would work great in Canada, but not so well in Texas. Also remember that a planisphere will only show stars, not planets, comets, or the Moon. Advice for using a planisphere is here.

  A similar product is the Stellarscope, which is kind of like a kaleidescope with a sky map on the opposite end when you look into it. The Stellarscope has different restrictors that you can insert to adjust it for different latitudes. The outside of the tube is rotated to the date and time you want to see. Again, the Stellarscope only shows stars and constellations.

  With either a Stellarscope, planisphere or flat map, you will need some kind of light to read it in the dark. You should use a red light or put red film over a regular flashlight. You don't need much light at all, but red light will help to preserve your night vision. The Stellarscope comes with a small red LED light.

  I cannot help you in choosing a telescope, but I would advise that the tripod you use with one is sturdy and stable. Many people are disappointed with their new telescope due to the inadequacies of the tripod and mount.
In my opinion, telescopes are very expensive and fragile tools that detract from the "big picture" and understanding of the motions of the heavens. One should be prepared to spend $1500 minimum for a decent telescope, mount, tripod, filters, and objectives, and even at that price there will always be more expensive additions that a telescope demands.

  Consider consulting your local university astronomy department, astronomical club or observatory. They often have free public viewings where you can use someone else's telescope and take advantage of their expertise.

Please visit the feedback page.              site home

information or comments to webmaster@theskytonight.com   

Remember, your local observatory, planetarium or university astronomy department are good local resources. They can give you very specific information about your part of the country or suggestions of good locations to view the night sky. There are links for each city's resources at the bottom of the city's page.

Todd Dugdale,

    Astronomical consultant for the Lunaria Lunar Almanac