Astronomical Airmass Planner

Author: Michael Newberry, Ph.D., Mirametrics, Inc.

This form creates a table of airmass and hour angle over a range of time. Use it for planning observations. The UT Date and Time for both beginning and end, plus the reporting Interval, are required. See "notes" below the results box. Click [Save] to save parameters, click [Load] to fetch them.  [Submit Comments]

Observing Site
Longitude (West < 0)   Latitude  
Deg

+/-deg
Min

 
Sec

 

 
Deg

+/-deg
Min

 
Sec

 
  Choose
 
Coordinates
Right Ascension   Declination    
Hour

 
Min

 
Sec

 

 
Deg

+/-deg
Min

 
Sec

 
  Object

optional  (19 chars, max)
Date & Time
UT Start   UT End (required)  
Year

yyyy
Month

 
Day

 
to Year

yyyy
Month

 
Day

 
   
Interval (required)
Hour

 
Min

 
Sec

 
to  Hour

 
Min

 
Sec

 
at Hour

 
Min

 
Sec

 
 
    Right-click on the table for options Column Separator 

Notes

Objects having airmass 20 or greater but not below the horizon are listed "@horizon".

The Tonight button calculates the UT for 5 hours before and 5 hours after tonight's midnight. To make this calculation, the longitude is used to determine the difference between midnight UT and midnight in your time zone. However, this does not account for daylight saving time or geopolitical adjustments to time zone boundaries (for example, actually being east of your time zone). If the "Tonight" times are not symmetrical around local midnight, you can force an adjustment by entering an offset into the Time Zone Correction field. For example, if "Tonight" ranges from 2h to 12h UT and you want it to be 3h to 13h, enter 1 into the Time Zone Correction field. The Time Zone Correction affects only the Tonight calculation.

To transfer the table into other software, click on the table, then select all text and copy to the clipboard. Paste the clipboard into the other software.

You can enter only the most significant digits in the date, time, and coordinate fields. For example use Time Step = 1 to get 1 hour, or enter 1 30 to get 1 hour 30 minutes, or enter 1 20 10 to get 1 hour, 20 minutes, and 10 seconds. Similarly, to get Time Step = 30 minutes, enter 0 30.

 

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