June signals the last month in our discussion of the star family Kaiwikuamo‘o, the Backbone. Kaiwikuamo‘o is described in the book “North Star to Southern Cross,” written by the late Bishop Museum astronomer Will Kyselka, and is one of four star families that modern voyagers use to organize the night sky.
To identify the star family Kaiwikuamo‘o, look to the northeast and locate Nahiku, the Big Dipper, a constellation of seven stars that resembles a ladle. The leading two pointer stars in the scoop of the Big Dipper point toward the star Hokupa‘a, aka Polaris, the north star. Polaris is at the very end of the Little Dipper constellation.
Both celestial ladles from the Big Dipper and the Little Dipper occupy the northeast quadrant of Kaiwikuamo‘o and the scoops pour toward each other.
Following the curving southerly arc of the Big Dipper’s handle leads to the brilliant red giant Hokule‘a, Arcturus, the fourth-brightest star in the night sky. With a celestial latitude of plus 19 degrees north, Hokule‘a is the zenith star for the Hawaiian Islands.
Continuing along the southerly track and crossing the celestial equator, we will arrive at Hikianalia, Spica, the southern pair star for Arcturus. Spica crosses just south of the Marquesas Islands, believed by researchers to be the homeland for the original settlers of the Hawaiian Islands.
Following Spica southeast we come to the trapezoid constellation Me‘e, or Corvus the Crow; a line through the center of the trapezoid and toward the southern horizon terminates our journey of “North Star to Southern Cross” with the constellation Hanaiakamalama, the Southern Cross.
The Southern Cross is a significant constellation for early oceanic explorers sailing south toward Tahiti. The Southern Cross points toward the direction Hema, south on our star compass.
Compasses, sidereal or magnetic, all work on the same principle. By pinpointing one known location along the horizon (magnetic north on the magnetic compass, or Polaris on the sidereal compass), you can identify the 32 headings of the magnetic compass and the 32 houses of the oceanic sidereal compass.
At Kahikinui, along Maui’s southern coastline, winds from the ‘Alenuihaha Channel buffet the rugged shoreline. Along this windswept coast and in the shadow of Haleakala is the archeo-astronomical site known as the panana at Hanamauloa. The panana is a pre-contact navigational device or “sighting wall”; its possible function may have been to identify the celestial meridian and the point we call Hema, south on our sidereal star compass.
The wall is approximately 29 feet long, 5 feet wide and 5 feet tall with a 2-foot notch at the center of the wall. Seaward of the wall 213 feet away sits an ahu, or stone cairn. When looking through the notch and in the direction of the cairn, an observer can see a relative line of direction southward along the celestial meridian. When Hanaiakamalama, the Southern Cross, is upright, it stands directly above the notch and frames the direction south. The panana at Hanamauloa serves as a navigational monument to voyagers from generations past.
Special events
June 20 marks the northern hemisphere’s summer solstice, the day when the earth’s north pole is at its maximum tilt toward the sun. On this day the northern hemisphere experiences its longest period of daylight; the day length for Honolulu on the solstice will be 13 hours and 25 minutes.
Evening observation
In the southern sky, careful observers will be able to see some notable stars and celestial objects. Just next to Hanaiakamalama we can see the two pointer stars Kamailehope, Alpha Centauri, and Kamailemua, Beta Centauri.
These two stars will appear to be about the same brightness, but they are quite different from each other. Beta Centauri is a triple-star system of three bright stars that are about 400 light-years away from us, meaning that it takes 400 years for light to travel from that star to Earth. Alpha Centauri, also a triple-star system of smaller and fainter stars, is the closest star system to our sun at only four light-years away.
So when you look at these two stars in the evening sky, the light from Alpha Centauri that enters your eyes left the star during the last U.S. presidential term, four years ago, and the light from Beta Centauri left the star before the United States was even a country, 400 years ago.
Not far from these notable stars, very careful observers will also be able to see the fuzzy light of a unique astronomical object, Omega Centauri. To find Omega Centauri locate Hanaiakamalama, the Southern Cross. From the crux of the cross draw a 45-degree line up to the northeast of the cross; as you follow this line you will see a fuzzy smudge about 12 degrees north of Kamailemua; this will be Omega Centauri. Omega Centauri is a globular cluster containing about 10 million stars as it orbits around the plane of the Milky Way galaxy.
Morning observations
Early-bird stargazers will enjoy a very different perspective of the night sky. As summer approaches, the sun will be rising earlier and the nights will be getting shorter. Throughout June, the sun will rise just before 6 a.m. and the light of dawn will color our sky starting just before 5:30 a.m.
In the early-morning hours, the bright planet Jupiter and the fainter planet Saturn will be high in the southwestern sky. These two gas giant planets will continue to accompany each other through our early morning sky with the red planet Mars about 73 degrees to the east of them.
By the second week of June, the incredibly bright planet Venus will rise just before the sun in the east.
Featured Mauna Kea discovery
Astronomers using the Keck Observatory on Mauna Kea and the Hubble Space Telescope have captured imagery of a rare type of galaxy from the earlier days of the universe. This galaxy is circular with a giant hole in the middle like a giant cosmic doughnut; its discovery is set to shake up our understanding of how galaxies formed in the early universe.
The galaxy, R5519, is about 11 billion light-years away, so we are seeing how it looked 11 billion years ago, just as our modern galaxies were beginning to form (only about 3 billion years after the birth of the universe).
“It is a very curious object that we’ve never seen before,” said lead researcher Tiantian Yuan, from Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D). “It looks strange and familiar at the same time.”
The galaxy is suspected to be a collisional ring galaxy, a type of galaxy that has been theorized but had not been discovered in the early universe until now. These galaxies can take on a “ring of fire” or “doughnut” structure due to collisions with other nearby galaxies. These collisions can also start up star formation processes as gas is condensing in the impacted areas.
The “doughnut hole” in R5519 is estimated to be about 3 million times the diameter of Powehi, the supermassive black hole imaged last year. By studying R5519 and looking for other collisional ring galaxies, astronomers can better determine when spiral galaxies, like the Milky Way, began to develop, leading to further research on how our own galactic home came into existence.
Learn more about this discovery on the Keck Observatory website: keckobservatory.org/ring-galaxy.
IUNE (JUNE ) SKIES AT 8 P.M. 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.