Featured Mauna Kea discovery/observation
The Institute for Astronomy at the University of Hawaii at Manoa hosted its annual open house April 10 for the first time since lockdowns began in 2020, which also coincided with the celebration of Powehi Day — a state-recognized day celebrating the first image of a black hole ever captured.
The black hole was imaged by the Event Horizon Telescope, a collaboration of telescopes from around the world including two on Mauna Kea — the James Clerk Maxwell Telescope and the Submillimeter Array.
In honor of its connection to Hawaii and Mauna Kea, this black hole located at the center of the Messier 87 galaxy, known as M87, was given the name Powehi by A Hua He Inoa, a collaborative naming program led by the ‘Imiloa Astronomy Center of Hawai‘i.
Powehi means “the adorned fathomless dark creation” or “embellished dark source of unending creation” and comes from the Kumulipo, an 18th-century Hawaiian creation chant.
Special events
As the sun sets in the west on the evening of May 15, the full moon will rise in the east with a lunar eclipse already in progress. Moonrise will begin at 6:54 p.m. with the moment of maximum eclipse visible for Hawaii occurring at 7:04.
From this point the moon will slowly grow brighter and less red until it passes out of Earth’s shadow at 8:50. While the moon often has a reddish look when it rises, the eclipse will cause this hue to last much longer than the average moonrise. Sky watchers might be able to view this celestial event from the eastern shores of our islands if the skies are clear.
Lunar eclipses only happen on full-moon nights as these are the phases at which the orbits of the sun, moon and Earth may align. According to the Hawaiian moon calendar, the full moon will occur on the night of Hoku.
As we approach mid- to late May, the islands will once again be able to witness a unique astronomical phenomenon: Lahaina noon.
Lahaina noon, a term coined by the Bishop Museum, is a phenomenon in which the sun passes directly overhead through a point called the zenith. When this happens, any upright object will no longer cast a shadow as the sun is at the exact center of the sky.
Hawaii experiences this due to its proximity to the equator in conjunction with the angle by which the sun travels overhead. In the months between the spring equinox and summer solstice, the sun rises and sets more and more in a northerly direction.
Lahaina noon is observed on different dates and at slightly different times on each island and even in different cities due to slight changes in latitude between locations.
The phenomenon will take place on May 17 at 12:20 p.m. in Kailua-Kona and on May 18 at 12:17 p.m. in Hilo, even though both towns are located on Hawaii island. Lahaina noon will take place in Honolulu on May 26 at 12:28 p.m.
For the exact date and time of Lahaina noon in your area, please visit the Bishop Museum website.
Hawaii will experience another set of Lahaina noons in July after the summer solstice.
The precise moment of Lahaina noon, when the sun is at the exact center of the sky, will only last a moment. At ‘Imiloa Astronomy Center, the mosaic “Voyage of the Navigator” is positioned exactly under a skylight so that during Lahaina noon the mosaic is perfectly illuminated by the sky light above.
Evening observations
As we fully embrace the spring sky, the navigational star family of Kaiwikuamo‘o will center itself in the early evening sky. This star family stretches like a great backbone connecting Hawaii’s people to the past.
The star family begins in the north with Hokupa‘a (the North Star), which will appear to remain in the same position in the sky while the rest of the stars trace paths around it over the course of the night. This occurs because Hokupa‘a sits exactly over the Earth’s North Pole, and therefore over the planet’s axis of rotation. That means that as stars move overhead while the Earth spins, Hokupa‘a will look like it is staying still.
From Hokupa‘a, the starline traces south to the shape of Nahiku, which is also commonly recognized as the Big Dipper. From Nahiku, the star family arcs toward the bright yellow star Hokule‘a and continues to Hikianalia. These two significant stars are the namesakes of the two famous modern voyaging canoes in Hawaii.
Near Hikianalia, observers will find an empty section of sky. Here, astronomers get the perfect viewpoint to look out and away from the Milky Way galaxy. In this specific section of the sky, astronomers can observe the Virgo supercluster of galaxies, an enormous collection of galaxies whose gravity is dragging the Milky Way across the universe. At the center of the Virgo cluster is the massive elliptical galaxy M87.
From Hikianalia, the star family passes through Me‘e before dropping straight down to Hanaiakamalama, also known as the Southern Cross. Stargazers can observe Hanaiakamalama rising higher and higher in the sky each evening after sunset as we settle more fully into these months of spring. Hanaiakamalama is the end point of our spring starline — Kaiwikuamo‘o (the Backbone).
At the beginning of the month, the bottom star of Hanaiakamalama will barely be visible after sunset, but by the end of the month it will sit fully visible and upright in our southern skies as soon as the sun sets. Hawaii is the only state from which Hanaiakamalama can be observed showcasing spectacular and unique celestial views.
Morning observations
Early-bird stargazers will enjoy a very different perspective of the night sky.
As summer approaches, the sun will rise earlier and the nights will get shorter. Throughout May, the sun will rise just before 6 a.m. and the light of dawn will color the sky starting at around 5:30.
During these early-morning hours, stargazers will be able to observe the movement of planets against the backdrop of the stars.
Throughout the past few months, early observers have been watching a cosmic dance with multiple planetary conjunctions.
A conjunction is when two celestial objects, typically planets, appear to be extremely close to each other in the sky from our perspective on Earth. In ancient Babylonian times, the conjunction of planets was considered to be a very significant event, as the motion of the planets was thought to predict the future.
While conjunctions are not considered to be scientifically significant today, they do make for quite beautiful events as two planets will appear to merge into one light. For example, on Saturday morning the planets Venus and Jupiter, some of the brightest objects in the sky, will appear to merge into one light as they go through a conjunction.
Throughout May, the planets of Venus, Jupiter, Mars and Saturn will all be visible in the early morning. On the morning of May 29, Jupiter and Mars will be less than 1 degree away from each other, concluding the series of planetary conjunctions.
As we finish watching this series of conjunctions, we are studying the stars in the same way people did long before telescopes. By tracking these planets, we take note of which planets “move” the fastest in the sky and can use this information to determine which planets are closest and farthest from the sun and from us.
Skywatch May 2022 by Honolulu Star-Advertiser
The ‘Imiloa Astronomy Center of Hawaii is a center for informal science education at the University of Hawaii at Hilo showcasing astronomy and Hawaiian culture as parallel journeys of human exploration.
