Skywatch: Planets, stars will shine brightly in February sky

The winter starline is known as Kekaomakali‘i, the bailer of Makali‘i. It rises out of the eastern horizon and arcs overhead in the shape of a scoop bailing water out of a canoe. It extends from Hokulei (Capella) in the northeast to Keali‘ikonaikalewa (Canopus) in the southeast, holding the constellations Heiheiona­keiki (Orion), Kapuahi and Makali‘i (Pleiades) within the safety of its bowl, then tips over after passing the meridian and “pours” these celestial figures out toward the western horizon.

If one envisions the horizon as a circle divided in two, one side of the circle is east, Hikina, meaning the “arriving” horizon, and the other is west, Komohana, meaning the “entering” horizon. The circle rotates on two celestial poles, with the meridian running overhead in between. With your back toward east you are facing west, which places north on the right or akau side, and south on the left or hema side.

All sidereal bodies — the sun, moon, planets and stars — move in parallel tracks from east to west, rising and setting in the same hemisphere of the circular horizon. Winds and swells move diagonally from quadrant to quadrant within the circle, northeast to southwest or southeast to northwest.

Between the tropics of Capricorn and Cancer, all sidereal bodies, winds and swells move east to west. Thus, sailing to Tahiti from Hawaii means keeping the sidereal bodies and weather to the port hull; returning to Hawaii from Tahiti is the reverse — you keep the starfield and weather to the starboard hull.

Hawaii traditionally had two six-month seasons: kau wela (summer) and hooilo (winter). The names of the 12 months and the particular 30-day lunar periods they pertained to differed from island to island.

The months referenced here are for Hawaii island. The summer months were: Ikiiki (May), Ka‘aona (June), Hinaia‘ele‘ele (July), Mahoe­mua (August), Mahoehope (September) and ‘Ikuwa (October). Winter season, hooilo, began in November and ran through April. The months were: Welehu (November), Makali‘i, (December), Ka‘elo (January), Kaulua (February), Nana (March) and Welo (April).

The monthly Hawaiian lunar calendar had 30 nights called po. Because the year actually had 12 months of 29-1/2 lunar cycles, over the course of one year the calendar would have drifted 10-3/4 days, as compared to the Gregorian calendar. To calibrate this difference and have the 30 names match the observable night sky, every three years or so the kahuna kilo hoku (one skilled at astronomical observations) would need to insert an additional month. We have no documentation of this process in Hawaii, but we know that it was a practice in the South Pacific.

Featured Mauna Kea discovery

In 2007 an astronomical mystery began which scientists are still working on unraveling today. Recent observations made with Gemini North Observatory on Mauna Kea will either help us solve or further deepen the mystery of the enigmatic phenomenon of fast radio bursts.

While most radio light sources can be detected over much longer time spans, fast radio bursts are radio flashes that last for only a few milliseconds; they appear as a single spike of energy without any change in strength over time. It is estimated that whatever force creates such bursts puts out as much energy in 5 milliseconds as the sun does in a month.

While the specific source of bursts remains a mystery, we know that they are occurring in other galaxies, outside our Milky Way. Until just recently, however, astronomers had not been able to pinpoint or secure an optical image of a specific host galaxy.

Astronomers couldn’t imagine their luck when there were able to identify a nearby spiral galaxy as the origin of a repeating fast radio burst. Gemini Observatory on Mauna Kea played a key role in this exciting discovery, which was recently published in Nature and presented at the meeting of the American Astronomical Society in Honolulu earlier this month.

Evening observations

Venus will continue to dominate the early evening sky through February. As the first object to appear in the western sky as the sun is setting, it is often referred to as the “evening star.”

Observers who look at Venus through a pair of binoculars or a telescope will also note that the planet does not appear to be a full circle.

This is because Venus is closer to the sun, so we see it going through phases, similar to the moon. Throughout February, Venus will be waxing and we will see most of the daytime side and a small portion of the nighttime shadow.

In early to mid-February, Mercury will also make a brief visit to our sky. From the beginning of the month until Feb. 19, careful observers can catch a faint Mercury low on the western horizon just after 7 p.m. The best night to catch Mercury will be on Feb. 10, when it will not set until 7:30 p.m.

Along the handle of the bailer, Kekaomakali‘i, the bright star ‘A‘a (Sirius) will stand out as the fifth brightest object in the sky, after the sun, the moon, Venus and Jupiter (which can be observed in the early morning sky). The point that we see as ‘A‘a, which means “burns bright,” is actually a double star system that consists of a larger A-type star and a smaller white dwarf star.

Morning observations

Throughout February the sun will rise around 7:11 a.m.

As dawn begins to color the sky around 6 a.m, three planets will be rising in the southeast. The faint planet Saturn will begin to pierce through the dawn sky, rising just before 6 a.m. in early February. Just above Saturn will be another notable gas giant planet, Jupiter, which will stand out in the early morning sky with significant brightness. Mars will be the highest of the three planets standing out with its famous and distinctive reddish color.

Not far from Mars will be a distinctive red giant star which is often mistaken for the red planet, Lehuakona. The Greek name of the star, Antares, literally means “rival to Mars” (Ares is another name for Mars) as the star’s red color made it easy to mistake for the rusty planet. The navigational name of the star, Lehuakona, translates as “southern Lehua blossom” referring to the red lehua blossoms on Hawaii’s native ohia Lehuakona marks the center of the famous shape of the starline Kamakaunuiomāui, or Fishhook of Maui, which appears to pull up the Milky Way from the southeastern horizon.

Farther south, early morning observers will also be able to catch the famous shape of the Southern Cross, Hanaiakamalama, accompanied by its two pointer stars east of the cross; Kamailemua (Beta Centauri) and Kamailehope (Alpha Centauri).

PEPELUALI (FEBRUARY) SKIES … 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 Hawaii, a center for informal science education at the University of Hawaii at Hilo showcasing astronomy and Hawaiian culture as parallel journeys of human exploration.