The twin stars in the bucket of the Little Dipper, Holopuni (Kochab) and Hokumau (Pherkad) are good clues for determining latitude in the southern hemisphere. When Holopuni and Hokumau make their nightly east to west journey across the night sky, they travel across the celestial meridian, an imaginary line that runs from the celestial north pole to the celestial south pole.
At the equator, when crossing the meridian, Holopuni and Hokumau attain altitudes of 16 and 18 degrees, respectively, above the northern point on the horizon.
As you sail south from the equator, Holopuni and Hokumau will get closer and closer to the horizon, losing a degree of altitude for every 60 nautical miles traveled south. When Holopuni and Hokumau have faded into the northern horizon and are obscured by clouds, you should be approaching the Tuamotu Archipelago, a band of 78 low-lying coral atolls. These atolls form a screen of islands that stretch about 500 miles from east to west. The best strategy to arrive in the Tuamotu Archipelago is to leave from the easternmost point of the Hawaiian islands — Hilo.
Pointing the canoe’s bow close to the direction of Manu Malanai, or southeast on the Hawaiian star compass, you would keep the canoe on a windward heading until making landfall. For sailing canoes, the regular landfall is the western edge of the Tuamotu screen, Mataiva, Tikehau, Rangiroa and Arutua.
About three days, or 72 hours, before you see the tops of coconut trees on the northern-facing shoreline, clues indicating that land is just beyond the horizon should be visible. The best indicator of outlying atolls are land birds. The manu-o-ku, or white tern, has a range of 120 miles from land. The noio, or noddy tern, has a range of about 40 miles from land. Land birds with young nestlings to feed will fly out to fishing grounds in the early morning and return to the island later in the day. One must be cautious of juveniles and young adults with no chicks to feed because they can wander far from land. It is more important to pay attention to groups of the right species rather than the solitary land bird.
Natural debris from islands such as coconuts, driftwood and palm leaves are also signs of land.
Normally, they would indicate land in the upwind direction of where the debris is drifting from. Large towering cumulus clouds above the interior lagoons of atolls will absorb the blue-green reflection of the trapped ocean below it. On the downwind side of atolls, the ocean loses some of its intensity as it wraps around the island. The seas become more quiet and the swells are more sorted and easier to read.
Once on a voyage, a navigator indicated to Hokule‘a crew member Kalepa Baybayan that the bow of the canoe had dried up, and they were no longer experiencing that chronic splash across the front deck. The navigator predicted that they were in the lee of a low-lying atoll; 15 minutes later, tops of coconut trees were sighted.
Special events
From mid to late October, the night skies will be decorated with the Orionid meteor shower, which will produce about 20 shooting stars an hour, one every three minutes when it peaks on Oct. 21. The shooting stars were left from the tail of Halley’s comet, which came through the inner solar system in 1986. On Oct. 23, Uranus will be at opposition with the Earth, where Uranus will rise at the exact same time as the sun sets. Uranus will be difficult to see because it is so far away. Even through a telescope, Uranus looks like a faint blue green dot.
Evening observations
As fall comes into full swing, higher up in the southern sky, the much fainter planets of Mars and Saturn will be visible. Although faint, Mars will be recognizable by its red color.
Setting in the west will be the “summer” starline of Manaiakalani. This starline is made up of three main pieces: the Navigator’s Triangle (also known as the Summer Triangle); Pimoe, a mischievous ulua fish; and Kamakunuiamaui, the fishhook of Maui.
Rising in the east will be Kalupeakawelo or the “Kite of Kawelo.” At the center of this starline is the “Great Square of Pegasus,” which represents the body of a kite as it is being flown. Going north of the great square is the “W” shape of ‘Iwakeli‘i and the house shape of Kamo‘i. The starline also stretches down into the southern sky and connects to some of the brightest stars in the southern sky during the fall season.
While looking toward the body of Kalupeakawelo, about 10 degrees north and west of the star Manokalanipo, you can see a small faint smudge in the sky. This is the Andromeda Galaxy, the closest full-sized galaxy to the Milky Way, and the only object outside of our galaxy that can be seen with the naked eye.
Morning observations
In October, the sun will rise around 6:30 a.m. As the days get shorter, there will be more opportunities to observe during the early morning hours. Around 5 a.m., the bright recognizable shape of Kaheiheionakeiki, or Orion, will be visible. Beneath Orion will be the incredibly bright star of A‘a, also known as Sirius.
September Skywatch by Honolulu Star-Advertiser on Scribd
Chad Kalepa Baybayan (Kalepa.Baybayan@hawaii.edu) serves as navigator-in-residence and Emily Peavy (Emily.Peavy@hawaii.edu) as planetarium technician support facilitator at the ‘Imiloa Astronomy Center of Hawai‘i, a center for informal science education at the University of Hawaii at Hilo showcasing astronomy and Hawaiian culture as parallel journeys of human exploration.
