21 Club Observer Award
of the
AstroCruisers Astronomy Club
The purpose of the 21 Club award is to give an achievable, enjoyable and educational challenge to beginning and traveling stargazers aboard cruise ships. The 21 Club is like a "Messier marathon" for beginning skywatchers, a fun and challenging activity that is a great way to introduce basic astronomical concepts while teaching novices how to find all first-magnitude stars (the brightest 21 stars, located in 18 constellations including five in the zodiac). Because Acrux, the first-magnitude star at the bottom of the Southern Cross, cannot be seen north of the southernmost part of the mainland U.S., the 21 Club is also an exotic challenge for more experienced observers living north of the Tropic of Cancer who sail in the tropics or southern hemisphere.
Requirements
- Observer locates and identifies all 21 first-magnitude stars with the naked eye during a cruise.
- Observer records time, date and geographic location of each observation in which star or planet is first observed.
- Observer's observations must be confirmed by experienced supervising starwatch leader (who does not have to be present when observations take place) during activity sponsored or approved by the AstroCruisers astronomy club's 21 Club Committee.
Special Award Endorsements
- One Night Stand (completed within 24 hours noon-to-noon local time except between noon December 31 and noon January 1)
- Auld Lang Syne (completed within 24 hours between noon December 31 and noon January 1 local time)
- Polar Bear (for observing all objects while north of the Tropic of Cancer)
- Plus One through Plus Five (for one to five visible planets observed and identified during observing period).
Starwatch supervisor has option of issuing "Honorable Mention" recognition to participants who identify fewer than all 21 first-magnitude stars.
When and Where to Observe
All 21 first-magnitude stars can be seen from about as far north as Ft. Lauderdale, where Acrux barely clears the horizon, to as far south as southern New Zealand, although it's only about as far south as Melbourne that they can all be seen in one night.
The freeware Windows program Planetary, Lunar and Stellar Visibility version 3.0.0 was used to calculate the following table of nights in 2005 that all first-maggers can be seen from specific locations under very good conditions. It is sufficient for planning purposes, although the actual dates of visibility will depend upon the skill of the observer, atmospheric conditions, local horizon and other such factors.
VISIBILIITY IN 2005 OF ALL FIRST-MAGNITUDE STARS IN ONE NIGHT
| Place | Latitude | Dates Visible |
|---|
| Palm Beach, Florida | 26° 46' N | Acrux too close to horizon to see |
|---|
| Freeport, Bahamas | 26° 31' N | Acrux too close to horizon to see |
|---|
| Ft. Lauderdale, Florida | 26° 05' N | 1/4 - 2/6 |
|---|
| Brownsville, Texas | 25° 57' N | 1/4 -2/6 |
|---|
| Miami, Florida | 25° 46' N | 1/3 - 2/6 |
|---|
| Nassau, Bahamas | 25° 05' N | 1/1 - 2/6 |
|---|
| Taipei, Taiwan | 25° 02' N | 1/1 - 2/7 |
|---|
| Key West, Florida | 24° 34' N | 1/1 - 1/14, 1/16 - 2/7, 12/30 - 12/31 |
|---|
| Tropic of Cancer | 23° 26' 22" N | 1/1 - 1/14, 1/17 - 2/7, 12/27 - 12/31 |
|---|
| Cabo San Lucas, Mexico | 22° 53' N | 1/1 - 1/13, 1/17 - 2/7, 12/25 - 12/31 |
|---|
| Honolulu, Hawaii | 21° 16' N | 1/1 - 1/12, 1/17 - 2/8, 12/20 - 12/31 |
|---|
| San Juan, Puerto Rico | 18° 28' N | 1/1 - 1/11, 1/19 - 2/9, 12/16 - 12/31 |
|---|
| Acapulco, Mexico | 16° 51' N | 1/1 - 1/11, 1/20 - 2/10, 12/15 - 12/31 |
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| Port-of-Spain, Trinidad | 10° 36' N | 1/1 - 1/8, 1/23 - 2/12, 7/31 - 8/6, 12/15 - 12/31 |
|---|
| Singapore | 1° 20' N | 2/9 - 2/16, 3/19 - 3/30, 5/3 - 5/8, 7/31 - 8/7, 9/7 - 9/11 , 12/14 - 12/20 |
|---|
| Mahe, Seychelles | 4° 37' S | 2/17 - 2/18, 3/15 - 4/10, 4/22 - 5/18, 8/1 - 8/8, 9/8 - 9/24, 11/14 - 11/18 |
|---|
| Darwin, Australia | 12° 28' S | 3/12 - 5/19, 7/1, 8/3 - 8/8, 9/9 - 10/3 |
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| Papeete, Tahiti | 17° 32' S | 3/10 - 5/16, 8/5 - 8/9, 9/11 - 10/3 |
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| Sydney, Australia | 33° 50' S | 3/29 - 4/20, 9/17 - 9/28 |
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| Cape Town, South Africa | 33° 56' S | 3/29 - 4/19, 9/17 - 9/27 |
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| Buenos Aires, Argentina | 34° 36' S | 3/30 - 4/17, 9/17 - 9/27 |
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| Montevideo, Uruguay | 34° 54' S | 3/31 - 4/16, 9/18 - 9/27 |
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| Auckland, New Zealand | 36° 51' S | 4/14 - 4/15, 9/20 - 9/26 |
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| Melbourne, Australia | 37° 52' S | 9/21 - 9/25 |
|---|
| Wellington, New Zealand | 41° 18' S | no days all first-magnitude stars can be seen |
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| Hobart, Tasmania | 42° 53' S | no days all first-magnitude stars can be seen |
|---|
| Christchurch, New Zealand | 43° 33' S | Capella too close to horizon to see |
|---|
Copyright 2002-2005 AstroCruisers. All rights reserved.
The address of this page is http://www.eyeonthesky.com/astrocruisers/21club.html.
Send e-mail to eyeonthesky@compuserve.com.
Last updated 11 March 2005.
