Larry McNish's
Night Sky Planner Version 1.2

Title:  For: 
Longitude: Deg: Min: WestEast      UTC Offset (Hrs): 
Latitude:   Deg: Min: NorthSouth   

Or Choose a city
and **set your Standard Time UTC Offset, then click Submit**
Remember title and location values.
Enter your Standard Time offset in "UTC Offset (Hrs)" above.
All times are displayed in Standard Time. If Daylight Saving time is
in effect at the designated location, add one hour to all event times.

Note changes to default parameters below:
Horizon Limits: Deg:      Mag Limit:
Order table by: Object # RA Dec mv Cons
Include Images. Show Max Altitude (+time +Azimuth). Include Remarks
Include: Messier Finest NGCs Caldwell Deep Sky Stars Other
Exclude: Objects determined to be not visible.
Observe from: to:

Set your parameters and click Submit to generate the table.

About the Night Sky Planner:

What is viewable in the sky tonight (or at some other date or place)?
  • Which of the 110 Messier objects?
  • Which of the 111 Finest NGC objects?
  • Which of the 109 Caldwell objects?
  • Which of the 113 Deep-Sky Wonders for Light-Polluted Skies?
  • Which of the 100 Brightest Stars?
  • Which of more than 60 Other fine objects for binoculars or small telescopes?
This web page will take your proposed date, your longitude, latitude, time zone offset from Universal (Greenwich) time, and display a list of the 600+ objects listed above. You can also supply a title for the table, as well as set "extinguishing" values for horizon limitations due to air purity, elevation and different types of twilight. You can also set a limiting visual magnitude value (mv) - the larger the number the more objects will be listed. You then select whether you want a table in order by object numbers, Right Ascension, Declination, Visual magnitude (mv), or Constellation. You can also turn on or off options to show a small image of the objects, include information when the object will be at maximum altitude and whether or not to include remarks about each object. You include object lists by checking them off - the more lists included the longer the list. Finally you can exclude objects either by selecting the option to exclude those that are not visible, or by setting your observing start time today and/or your observing end time today or tomorrow. Just enter your parameters and click Submit. (Then wait until the table generates.)

Note - with more than 600 objects in the database, a full list can be 50 printed pages long or more!

Reading the resulting table:
ImageIf you select the "Include Images" option before clicking Submit, a small picture of the object will be shown here. Note - This may mean downloading a lot of thumbnails even though not all objects have images.
ObservedUse this column to check off the objects as you observe them.
If the object cannot be observed on the chosen night, the Planner will fill this in with:
  • "not poss D" - the object's Declination is too low for your horizon limit
  • "not poss S" - the object is just too near the sun to be seen after sunset or before sunrise due to the Astronomical Twilight effect
  • "not poss A" - the highest altitude attained between sunset and sunrise is still below your horizon limit
In some cases more than one will apply and each reason will be shown. If an object can not be viewed for any of these reasons, the column Verified will be crossed out. If you select "Exclude: Objects determined to be not visible", then the list will not contain any object not visible for any of these reasons. If you limit the observing time to later than "sunset today" or earlier than "sunrise tomorrow", more objects will be unobservable (or excluded) since they will not reach a viewing altitude during the (shortened) observing session.
VerifiedIf your viewing requires independent verification of sightings, the "verifiers" can use this column to initial the sightings of each object.
O#The number of the object. There is some controversy around the identity of some Messier objects. The identities used here are those in the RASC Observer's Handbook. M=Messier objects, N=Finest NGC objects, C=Caldwell objects, D=Deep-Sky Wonders for Light-Polluted Skies, S=Brightest Stars, O=Other fine objects for binoculars or small telescopes. You can control which object lists are included or excluded via the checkboxes.
NGC#The NGC (New General Catalogue) number for the object. Since a number of objects do not have NGC numbers, other common designations may appear here. For the 100 Brightest Stars, the SAO (Smithsonian Astrophysical Observatory compendium) catalogue number is given.
PolarThis designates which objects are circumpolar from the latitude selected and can theoretically be observed any time that night although the "best" time would be when they are highest in the sky to avoid horizon effects. It reports 'Yes' if it's circumpolar, and 'Yes**' if it's circumpolar and very close to the Sun's RA. In the latter case it would be best observed just after sunset or before sunrise, otherwise it may be too low.
TypeThe type of object as given in the RASC Handbook or other source.
ConsThe constellation associated with the object.
RA hr and RA minThe Right Ascension of the object (2000.0).
Dec° and Dec minThe Declination of the object (2000.0).
Max Alt°
@ time
@ Azm°
If you select the "Show Max Altitude" option before clicking Submit, the following 3 columns will also be shown:
  • Max Alt° - the maximum altitude above the horizon the object will achieve between sunset and sunrise
  • @ time - the local time when the maximum altitude is reached
  • @ Azm° - the azimuth angle when the maximum altitude is reached
mvThe visual magnitude of the object. You can limit the number of objects by choosing an mv value - the larger the number, the more objects will be listed. Choosing a small number will list only the brightest objects (e.g. for binocular viewing). (When I was not able to find a reliable magnitude value in the original source data I put in 5.678)
SizeThe dimensions of the object in arc minutes. (Planetary sizes are given in arc seconds.)
Dist KlyThe estimated distance of the object in Kilo light years. For the 100 Brightest Stars this is light years not Kilo light years. One Kilo light year = 9.460536x1018 m = 306.595 parsecs = 5.878504x1015 mi.
RemarksComments from the RASC Observer's Handbook and/or other sources. Entries marked "!!" are considered "showpiece" objects.

  • There are discrepancies in the original source data. There are variations in RA, Dec, Visual magnitude etc. for objects that appear on more than one list. At this time I have not attempted to resolve these differences (except for blatant errors).
  • A small graphic is shown beside the times of Moonrise and Moonset to show the approximate phase of the moon for the chosen day and the next day.
  • This program does not calculate the effect of the Moon's phase or brightness on the observations - Deep sky observing should always be scheduled near New Moon.
  • If the Moon does not rise or set on a particular day that time is shown as xx:xx.
  • To save your title, longitude, latitude, and UTC offset settings for the next time you use the Night Sky Planner, check the "Remember New Values" checkbox before clicking Submit. This will store the settings in a small "cookie" on your PC. Revisiting this site or clicking the Reset button will then reset any values to the "saved" values. To eliminate the set of saved values click the small button to the right of the Reset button to delete the cookie.
  • To fit the results on the pages properly, set your Internet Explorer Page Setup margins to 0.25 or 0.3 inch and print in landscape mode.
  • For Caldwell planetaries a size of 0.3/2.2 means that the bright nucleus is 0.3' across while the faint outer shell spans 2.2'.
  • Order by RA lists the objects from lowest to highest RA, and from most southerly to northerly Decl for duplicate RA values.
  • Order by Dec lists the objects from most southerly to northerly Decl, and from lowest to highest RA for duplicate Dec values.
  • Order by Cons lists the objects sorted by Constellation, and within each constellation from lowest to highest RA, and from most southerly to northerly Decl for duplicate RA values, allowing you to "sweep" from right to left and from bottom to top of the constellation (N hemisphere).
  • Order by mv lists in visual magnitude order with no other sorting at this time.
  • All times are displayed in Standard Time.
  • If Daylight Savings time is in effect at the designated location, add one hour to all event times.
Other Notes:
  • Copyright © 2005-2016 Larry McNish All Rights Reserved
  • Disclaimer: I assume no liability for the use of this web page.
  • Please link to this page rather than copying it.
  • This page should work on Internet Explorer 5 and later and Netscape 6 and later. (Netscape 6 is very slow - I recommend Netscape 7 or later.)
  • All the calculations are done on your PC using JavaScript - the slower your computer, the longer the table takes to appear.
  • Except for high latitudes, Sun rise/set times are accurate to within a minute or two.
  • Some of the JavaScript used to calculate these values was written by and is Copyright © Peter Hayes 2001-2016. His website can be found at
  • Current weather information for Canadian centres can be obtained from the Environment Canada web site at
  • Current Canadian Clear Sky information can be obtained from the Clear Sky Clock page at
  • Messier images from:
  • NGC Finest images from:
  • Star Data from (The SIMBAD Astronomical Database)
  • See for a lot of nice images
  • For Caldwell objects - see
  • Not all Caldwell objects have thumbnails (and a lot are duplicates of NGC Finest objects)
  • Not all "Deep-Sky Wonders for Light-Polluted Skies" have thumbnails (a lot are stars, and a lot are duplicates of Messier or NGC Finest objects)
  • Currently only a couple of "100 Brightest Stars" thumbnails are available.