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Jan 5 18

Secrets from Vesta and Ceres: Results of NASA’s Dawn Mission

by Imiloa Astronomy Center

‘Imiloa presents Dr. Schelte Bus, Deputy Director at NASA IRTF
Date: Fri. Jan. 19
Time: 7:00 p.m.
Cost: $10, $8 for members (member level discounts apply)

NASA’s Dawn Spacecraft is on a mission to study Vesta and Ceres, the two largest members of the asteroid belt. These diverse asteroids offer crucial scientific clues into the birth of our Solar System some 4.6 billion years ago. Learn more about this epic quest for knowledge in ‘Imiloa’s Maunakea Skies talk on Friday, January 19 at 7:00 p.m. with Dr. Schelte “Bobby” Bus, Deputy Director at the NASA Infrared Telescope Facility (IRTF) on Maunakea.

 

 Although the massive asteroids Vesta and Ceres both hold similarities that help us understand the formation of our Solar System, they have many differences in their geological makeup. Vesta has a rocky body, while Ceres is believed to contain large amounts of water and has an icy surface. Vesta’s south pole contains a massive crater measuring 285 miles across and 8 miles deep caused by a giant collision that gouged out one percent of its volume! This collision blasted out over a half a million cubic miles of rock into outer space. Scientist believe that this single collision is the cause for about 5 percent of all meteorites discovered on Earth.

 

After ten plus years of exploration, the Dawn Mission is nearing its end. The amazing images and measurements that have returned from this mission are leading scientists to a better understanding of what we see today in our Solar System.  Dr. Bus will share highlights from the Dawn Mission, paired with a discussion on the ground-based observations, like those made at NASA IRTF on Maunakeawhich have helped enhance the scientific return from this exciting mission of discovery.

Artists concept of NASA’s Dawn Spacecraft (nasa.gov)

 

Dr. Bus received his doctorate in planetary science in 1999 from the Massachusetts Institute of Technology.  In 2000, he moved to Hilo to accept a position with the University of Hawai‘i’s Institute for Astronomy as a staff astronomer for NASA IRTF. He became Deputy Director of NASA IRTF in 2017. His research focuses on the physical properties of asteroids and how processes such as collisions alter the asteroid belt, helping to feed material like meteoroids and Near-Earth Asteroids (NEAs) into near-Earth space.

 

Hosted by Planetarium Technician Emily Peavy, ‘Imiloa’s monthly Maunakea Skies program includes observational highlights of the current night sky over Hawai‘i, with the audience able to view prominent constellations and stars visible during this time of year. Maunakea Skies planetarium presentations are held on the third Friday of each month. General admission tickets are $10 and $8 for ‘Imiloa members (member level discounts apply). Pre-purchase tickets at ‘Imiloa’s front desk or by phone at 808-932-8901.

 

Dec 22 17

Ianuali (January) Sky Watch 2018

by Imiloa Astronomy Center

By Chad Kālepa Baybayan & Emily Peavy, ‘Imiloa Astronomy Center of Hawai‛i

Astronomical Explorations of 2017:
From the completion of the epic voyage of Hōkūle‘a to the naming of an asteroid detected from Hawai’i, and the latest findings of gravitational waves in space, 2017 has been an exciting year for astronomical explorations on Earth and in space.

In June of 2017, the Mālama Honua Worldwide Voyage of Hōkūle‘a culminated with reentry into Hawaiian waters, bringing to a close the widely publicized and closely monitored three-year international voyage. On its voyage around the world, navigating by the light of the stars and other clues from nature, Hōkūleʻa sailed an impressive 44,000 nautical miles, stopped at over 150 ports, visited 23 countries, and enlisted approximately 250 crewmembers. This canoe is currently conducting a Mahalo Sail around the islands in Hawaiʻi.

 

`Oumuamua (Photo Credit: ESO/M. Kornmesser)

ʻOumuamua, meaning scout or leader, is the first observed asteroid to visit Earth from interstellar space. Its brief visit to our solar system was only recently discovered ten weeks ago by University of Hawaiʻi researcher, Rob Weryk, using the universityʻs Pan-STARRS telescope on the summit of Haleakalā. This seven-football field length asteroid is now on a path that is taking it rapidly away from Earth and the sun to continue its journey into deep space. According to researchers the asteroid could be rocky with a surface that possesses a high metal content. ʻOmuamua’s name was conceived through collaborative efforts between University of Hawaiʻi at Hilo and ‘Imiloa Astronomy Center, which have adopted a goal of assigning Hawaiian names to all Hawaiʻi based astronomical discoveries. (Read more on the naming of ʻOumuamua here). 

 

An artist’s impression of gravitational waves generated by binary neutron stars, NASA.

Gravitational waves, which are ripples in space predicted by Einstein in his theory of relativity, were first observed by astronomers and physicists in 2015.  Researchers have since detected other gravitational waves and have assumed that the collision of black holes produce the strongest gravity waves.  However, on August 17th of 2017, a historic discovery was made of gravitational waves emitted from a Kilonova, a neutron star merger, a type of event that had been theorized but never observed. Astronomers can now use this gravitational wave detection to locate light emitted from the collision.  This revolutionary discovery marks a new era and a whole new way for astronomers to observe the universe.

 

Navigating the night sky with Hawaiian Star Compass:
The circle of the horizon gives the physical shape to the Hawaiian Star Compass which has been discussed in previous columns. To make the compass functional the navigator memorizes the rising and setting points of key stars. To organize the night sky the celestial sphere is divided into four even sections, which are identified with a specific “starline.”   A recent creation of the voyaging community, the four starlines follow traditional Hawaiian themes and are used as a heuristic technique to learn and acquire navigational skills.

Starlines are a collection of bright stars and constellations that line up north to south.

The four starlines are, Kekāomakaliʻi (The Bailer of Makaliʻi), Kaiwikuamoʻo (The Backbone), Mānaiakalani (The Heavenly Fishing Line) and Kalupeakawelo (The Kite of Kawelo). Because each is most prominent in the night sky at a particular time of year, they also serve as seasonal starlines for winter, spring, summer, and fall.  

 

The winter starline, Kekāomakaliʻi, is in the shape of a canoe bailer, scooping up the stars on the eastern horizon and emptying them out in the west during its nightly transit across the sky. The scoop part of the bailer is made up of the northernmost bright star Hōkūlei, Capella, in the constellation Auriga. Hōkūlei rises in the star house Manu Koʻolau. The bailer arcs towards the eastern horizon and the constellation Nāmāhoe (The Twins), Gemini, and the two bright stars Nānāmua (Looking Forward), Castor; and Nānāhope (Looking Back), Pollux.

 

The starline turns south towards the direction of the constellation Puana (Little Dog), Procyon, and continues southward to the brightest star in the night sky, ʻAʻā (Burning Brightly), Sirius. The handle of the bailer is made up of ʻAʻā and the second brightest star in the night sky, Kealiʻikonaikalewa (Chief of the Southern Skies), Canopus.

 

The scoop of the bailer is filled with visible and identifiable constellations. Closest to ʻAʻā is Kaheiheionākeiki (Cats Cradle), Orions Belt, a Hawaiian string game played on the fingers of island children. The northernmost star of the three that forms the belt of Orion, Mintaka, marks the eastern star house, Hikina. Moving northwest and through Orion’s Belt will lead you to Kapuahi (Sacred Fire), Aldebaran, the eye of Taurus the Bull. Continuing along the northwest direction is the fuzzy constellation, Makaliʻi, Pleiades, in the eastern evening sky which also marks the beginning of the Makahiki season, a time when the Hawaiian chiefly class collected tribute and the commoner class celebrated with athletic competitions.

 

Thus, the four starlines are used as contemporary tools for learning and organizing the night sky in the context of Hawaiian culture.

 

January’s night sky:
The night sky of 2018 starts off with another supermoon on January 1st.  As mentioned in last month’s column, the moon does not orbit around Earth in a perfect circle; it orbits in an ellipse or oval shape, which means that the moon’s distance from Earth changes as it orbits.  When the moon’s distance is closest to Earth, that special location on the moon’s orbit is known as perigee. A supermoon occurs when the moon is full and lines up with the perigee.

 

As the starline of Kekāomakali‘i rises in the east, the starline of Kalupeakawelo will be setting in the west. Just to the east of Kalupeakawelo, beneath ‘Iwakeli‘i (Chief Frigate Bird) Cassiopeia, will be the faint but beautiful Andromeda Galaxy. This is the only large galaxy visible to the human eye.

 

There will be two full moons in January; one on the first day of the month and one on the last. When this happens the second full moon is often referred to as a blue moon even though the moon’s color remains the same. On January 31st, the blue moon will also coincide with the moon’s perigee, giving January its second supermoon. To top it off, between 3pm and 5pm (HST), the moon will pass through the Earth’s shadow in a lunar eclipse, which is often referred to as a “blood moon.” On January 31st, look forward to viewing a “super blue blood moon.”

 

Early Morning Observations  

The early morning hours provide a very different view of the sky. Throughout January, sunrise occurs near 7 am, giving early risers a beautiful view of the sky and the famous Nāhiku (Big Dipper) will be in the northeast direction. On January 6th, Mars and Jupiter will come together in a conjunction and the planets will appear to be almost on top of each other. The best viewing time is 5 am.

 

The ‘Imiloa Astronomy Center of Hawai‘i is a world-class center for informal science education located at the UH Hilo campus, showcasing astronomy and Hawaiian culture as parallel journeys of human exploration, guided by the light of the stars. Chad Kālepa Baybayan (Kalepa.Baybayan@hawaii.edu) serves as Navigator-in-Residence and Emily Peavy (Emily.Peavy@hawaii.edu) as Planetarium Technician Support Facilitator.

Dec 7 17

Fantastic Creatures on Display at ‘Imiloa for the Holidays

by Imiloa Astronomy Center

It’s beginning to look a lot like Christmas at the ‘Imiloa Astronomy Center, where a special origami-bedecked holiday tree went on display on Tuesday, November 27.  The tree features a unique collection of mythic and fantastic creatures folded by origami artist volunteers from across the U.S. and abroad.  These models were originally displayed on the 2007 Holiday Tree at the American Museum of Natural History in New York City.

 

Colorful mermaids, unicorns, angels, centaurs, Pegasus’s, dragons, and even a gargoyle and Medusa can be found dancing among the branches of the lighted 7’ tree in the ‘Imiloa atrium.  The tree is topped with a dramatic red Kusudama Star folded especially for ‘Imiloa by Dr. Julien Lozi, Senior Optical Scientist at Subaru Telescope.

 

The intricately folded fantastic creatures are part of an origami collection generously donated to ‘Imiloa two years ago by Al Miyatake. Born and raised in Hawai‘i, Miyatake was a friend of the Center and longtime Japan Airlines manager who for many years created an annual origami holiday tree at the JAL check-in counter at Kona International Airport.  Assisting in his efforts were his mother-in-law, Kyoko Kondo, and many talented friends from Origami USA, the New York-based national origami society which organizes volunteer folders to decorate the tree which has become a nearly 50-year holiday tradition at the American Museum of Natural History.

 

Margaret Shiba, ‘Imiloa’s Director of Institutional Advancement, comments that “Our holiday tree this year is dedicated to the memory of Al Miyatake, who passed away in Kona in March.  As an origami enthusiast, Al worked tirelessly to share the now-universal art of paper folding with people everywhere, and we invite the community to stop by and admire the legacy he has left here at ‘Imiloa.”  Executive Director Ka‘iu Kimura adds, “This year’s tree has another special meaning for ‘Imiloa because of the professional connections we enjoy with our programming partners at the American Museum of Natural History in New York!  What a privilege to have inherited their origami models and their holiday tree tradition!”

 

‘Imiloa’s holiday tree will be on display into January in the atrium. The ‘Imiloa Astronomy Center is open to the public Tuesday-Sunday, from 9:00 am to 5:00 pm. For more information call 932-8901.

Nov 30 17

Feel, See and Color the Universe

by Imiloa Astronomy Center

‘Imiloa presents Dr. Gordon K. Squires, Thirty Meter Telescope  (TMT)
Date: Fri. Dec. 15
Time: 7:00 p.m.
Cost: $10, $8 for members (member level discounts apply)

Scientists have teamed up with artists to create astonishingly detailed visuals to help us better understand complex astronomical discoveries—presenting science as stunning works of art that allow us to view astronomy through a different perspective. Learn more about the fascinating connections between art and science at ‘Imiloa’s Maunakea Skies talk on Friday, December 15 at 7:00 p.m. with Dr. Gordon K. Squires, Lead of Communications, Education and Public Outreach at the Thirty Meter Telescope (TMT).

 

Dr. Squires will lead the audience through fascinating examples of how his team creates visualizations to illustrate revolutionary scientific discoveries. A recent discovery that he will discuss is how scientists have detected the gravitational waves from a neutron star merger, which is how gold originated in the universe. Additionally, in March of this year, astronomers confirmed the discovery of TRAPPIST-1, a unique planetary system which hosts 3 habitable planets orbiting a small cool star. For both of these discoveries Dr. Squires and his team worked to create stunning visualizations to illustrate the “art of gravitational waves” and the “art of exoplanets”. Combining art and science in this way allows us to understand these discoveries, and allows us to imagine what we would witness if we could physically travel to these systems in person.

Pictured: A Kilonova, neutron star collision: the predicted source of all gold in the universe. Kilonovae were theorized but not observed until earlier this year when scientists detected gravitational waves from such an event at 130 million light years away.

Exploring the TRAPPIST-1 planetary system and following the trail of gold in the universe involves many telescopes and facilities on Earth and in space working in collaboration. Dr. Squires will highlight the role of multi-observatory science and discuss the contributions that TMT will provide for these and other astrophysical phenomena. While first-light observations from the Thirty Meter Telescope (TMT) are still several years away, recent discoveries from other observatories provide tantalizing insights into what TMT will one day reveal.

 

Dr. Squires leads the TMT International Workforce Development, Education, Public Outreach and Communications (WEPOC) efforts. His team– the IPAC Communications and Education team– is co-located at Caltech/IPAC and provides WEPOC support for a number of astronomy and physics-related projects including TMT, NASA’s Spitzer Space Telescope, the Herschel Space Observatory, the Wide-field Infrared Survey Explorer, Galaxy Evolution Explore, Kepler, LIGO and the IPAC archives. Dr. Squires is a co-investigator in NASA’s Science Mission Directorate (SMD) Science Activation program called Universe of Learning. He received his Ph.D. in Astrophysics from the University of Toronto in 1995. He was awarded the Doctoral Prize by the Natural Sciences and Engineering Research Council for the most outstanding Ph.D. thesis in Canada and the Plaskett Medal by the Canadian Astronomical Society for the most outstanding thesis in astronomy, both in 1995. His research explores the old, distant universe, enabling us to better understand how galaxies evolved and formed billions of years ago, and probing into the nature of the dark matter via weak gravitational lensing.

 

Hosted by Planetarium Technician Emily Peavy,‘Imiloa’s monthly Maunakea Skies program includes observational highlights of the current night sky over Hawai‘i, with the audience able to view prominent constellations and stars visible during this time of year. Maunakea Skies planetarium presentations are held on the third Friday of each month. General admission tickets are $10, $8 for ‘Imiloa members (member level discounts apply). Pre-purchase tickets at ‘Imiloa’s front desk or by phone at 808-932-8901.

Nov 27 17

Kekemapa (December) Sky Watch

by Imiloa Astronomy Center

By Chad Kālepa Baybayan & Emily Peavy, ‘Imiloa Astronomy Center of Hawai‛i

Mastering any skill takes passion and a commitment of time. Once achieved, a skill can last a lifetime of practice, but it is accessible only to the master unless it is passed on to others. Such is the story of the Satawalese star compass, Pa‘afu, used by the late master navigator, Mau Piailug, and our more modern Hawaiian star compass created by master navigator, Nainoa Thompson.

 

Born to the given name of Pius Piailug in 1932, Piailug was raised in the village of Weiso on the tiny coral atoll of Satawal in the Yap State of the Caroline Islands, part of the Federated States of Micronesia. At age five, Piailug attended Weriyeng, one of the last two schools of traditional navigation, for apprentice navigator training and went on to study with Angor, a skilled and recognized master navigator. At the age of eighteen, Piailug was initiated into the rank of Palu, master navigator, through a generations-honored ceremony called Pwo. For the next fifty years Satawal would not witness another Pwo ceremony until 2007, when five Hawaiian and eleven Satawalese men were initiated.

 

Piailug’s penchant for sailing in all weather conditions earned him the name “Mau” from the Satawalese word maumau, meaning strong. Piailug trained and mentored native Hawaiian master navigator, Nainoa Thompson, who in turn developed a modern system of wayfinding, or non-instrument navigation, using the Hawaiian star compass.

The Hawaiian star compass is comprised of 32 houses spaced equally at 11.25˚ intervals around the circle of the horizon. Both compass systems, the Satawalese and the Hawaiian, feature “arriving” horizons (hikina-east) and “entering” horizons (komohana-west). The arriving horizon, east, in the Pa‘afu system is named for stars and given the prefix, Tan. The entering horizon, west, is identified with the prefix, Tupul.

 

The Hawaiian star compass uses a star’s declination to position the stars along the edge of the star compass and to identify what house it rises and sets in. In astronomy term declination in astronomy is comparable to geographic latitude projected onto the sky, called the celestial sphere, and is measured in degrees north (+) or south (-) of the celestial equator, not exceeding 90˚, the northern and southern most point of the celestial sphere. The star Hōkūle‘a, Arcturus, rises and sets at +19˚North of the celestial equator, rising near the center of the star house ‘Āina Ko‘olau and setting in ‘Āina Ho‘olua. The star Hikianalia, Spica, rises and sets at -11˚ South of the celestial equator, rising from the center of the star house Lā Malanai and setting in Lā Kona. Mintaka in Orion’s belt with a declination of 0˚ rises in the star house Hikina and sets in the star house Komohana as it lies on the celestial equator. Nainoa Thompson incorporated a working list of 110 stars to the building of his Hawaiian star compass.

 

The reason a star compass works so well for the latitudes between Hawai‘i and Tahiti is because we inhabit an area of ocean known as the Tropics, between the margins of 23.5˚ North and 23.5˚ South, between which the rising and setting paths of the stars, sun, moon, and planets appear to be fairly vertical. However, when we travel further north or south the paths of these objects become more inclined until they become parallel to the horizon at the poles.  Thus, at the latitudes of the far north or south, wayfinders need to reply on other techniques. The Inuit of the arctic north, for example, use a traditional system called sastrugi, in which they determine direction based on observation of snow-formed ridges on the surface of ice, shaped by the wind.

 

December’s night sky

On December 3, be on the lookout for a supermoon, which is when the full moon’s distance is closest to earth, at a special location on the moon’s orbit known as perigee. The moon does not orbit around earth in a perfect circle; it orbits in an ellipse or oval shape, which means that the moon’s distance from earth changes as it orbits. Every month the moon passes through perigee and when a full moon lines up with the perigee, it’s called a supermoon and will appear to be slightly larger in the sky.

 

Rising from the east, throughout December, will be the distinctive star cluster of Makaliʻi, also known as the Pleiades. This stellar open cluster stands out with its seven brightest stars being clearly visible to the naked eye. The stars in the cluster were all born from the same nebula about 100 million years ago. As these stars are around the same age, the cluster can be used as a laboratory for the study of stellar evolution.

 

Considered by many to be the best meteor shower of the year, the Geminids Meteor shower runs from early to mid-December. Multiple meteors per minute are expected to be occurring on the night of December 13, marking the peak of the shower.

 

Winter Solstice for the northern hemisphere takes place on December 21, where the sun will rise and set at its southernmost position in the sky. The sun will have a low arc across the sky, making it the shortest period of daylight for the whole year.

 

Early-morning observation

Daylight in December arrives later as the sun rises just after 6:40 am. In the early morning hours of 3:00 am as Mars rises from the east, the rusty red planet will be distinguishable among the sea of stars by its red-colored iron-oxide soil.  As sunrise approaches, the bright planet of Jupiter will rise from the east at about 5:00 am. As the 4th brightest object in the sky (after the sun, moon and Venus), Jupiter will still be visible as the sun begins to rise.  Jupiter owes its brightness to its thick atmosphere which reflects back much of the light that comes from the sun.

 

In the northeast the seven stars of Nahiku, which shares the same stars of the Big Dipper, are easily noticeable. Tracing the arc of stars representing the Big Dipper’s handle down towards the east, one can find the bright star Hokule‘a (Arcturus). This star is the namesake of the famous Hawaiian voyaging canoe which completed its worldwide voyage earlier this year.

 

December moon phases

Full Moon: 5:47 am HST, Sunday, December 3

Last Quarter Moon: 9:51 pm HST, Saturday, December 9

New Moon: 8:31 pm HST, Sunday, December 17

First Quarter Moon: 11:03 pm HST, Monday, December 25

The moon’s phase is determined by its position in relation to the sun and the earth. The designations of Full, Last Quarter, New and First Quarter refer to specific orientations of the moon, sun and earth. Listed above are the exact times the moon will be in the precise orientation; however the moon will not necessarily be visible in Hawai‘i’s sky at the specific time.  Due to the moon’s brightness, the best time for stargazing without its interference will be the week around New Moon (November 18).

 

Nov 21 17

Earth’s First Known Interstellar Visitor Unmasked, Named ʻOumuamua

by Imiloa Astronomy Center

In October, astronomers at the University of Hawaii’s Institute for Astronomy (IfA) made a stunning discovery with the Pan-STARRS1 telescope – the first interstellar object seen passing through our Solar System. Now, an international team lead by Karen Meech (ifA) has made detailed measurements of the visitor’s properties. “This thing is very strange,” said Karen Meech.

Artist’s impression of the interstellar asteroid `Oumuamua

(Photo Credit: ESO/M. Kornmesser)

Originally denoted A/2017 U1 (with the A for asteroid), the body is now the first to receive an I (for interstellar) designation from the International Astronomical Union, which created the new category after the discovery. In addition, it has been officially given the name `Oumuamua. The name, which was chosen in consultation with ‘Imiloa Astronomy Center and Hawaiian language expert Larry Kimura, reflects the way this object is like a scout or messenger sent from the distant past to reach out to us (`ou means “reach out for”, and mua, with the second mua placing emphasis, means “first, in advance of”). The object’s full official name is 1I/2017 U1 (`Oumuamua), and can also be correctly referred to as 1I, 1I/2017 U1, and 1I/`Oumuamua.

 

`Oumuamua is rapidly fading as it heads out of the Solar System and recedes from both the Sun and the Earth, so getting new observations as fast as possible was crucial. The IfA team – including those who discovered 1I – was already prepared to rapidly follow up solar system discoveries from Pan-STARRS, which is operated by the IfA and funded by NASA. “We were able to rapidly develop a follow-up strategy on a very short timescale. It is exciting to think that the brief visit by `Oumuamua gave us the opportunity to do the first characterization of a sample from another solar system,” says Meech. As a result, they are the first to publish their results, appearing in the November 20th online issue of the journal Nature.

 

The team gathered data from telescopes around the world, including the Canada-France-Hawaii Telescope (CFHT), the United Kingdom Infrared Telescope (UKIRT) and the Keck Telescope on Maunakea, the Gemini South telescope, and the European Southern Observatory (ESO) Very Large Telescope (VLT) in Chile. Marshalling all of these resources yielded a wealth of data that revealed `Oumuamua’s unusual nature.

 

“We had to act quickly,” explains team member Olivier Hainaut from ESO in Garching, Germany. “`Oumuamua had already passed its closest point to the Sun and was heading back into interstellar space. This felt very much like the beginning of the famous science fiction story, Rendezvous with Rama.”

“Needless to say, we dropped everything so we could quickly point the Gemini telescopes at this object immediately after its discovery,” said Gemini Director Laura Ferrarese, who coordinated the Gemini South observations for Meech’s group.

 

“The CFHT data was absolutely critical for understanding the light curve, for our initial understanding of the orbit, and determining that this object was more like an asteroid and not a comet,” noted IfA’s Richard Wainscoat.

 

“What we found was a rapidly rotating object, at least the size of a football field, that changed in brightness quite dramatically,” according to Meech. “This change in brightness hints that `Oumuamua could be more than 10 times longer than it is wide – something which has never been seen in our own Solar System,” according to Meech.

 

“An axis ratio like that is truly extraordinary – we have never seen anything in the solar system that is this elongated”, says Lance Benner, a specialist in radar imaging of near-Earth and main-belt asteroids at the Jet Propulsion Laboratory in California.

 

`Oumuamua does have some similarities to small objects in the outer Solar System, especially the distant worlds of the Kuiper Belt – a region of rocky, frigid worlds far beyond Neptune. “While study of `Oumuamua’s colors shows that this body shares characteristics with both Kuiper Belt objects and organic-rich comets and trojan asteroids,” said Meech, “its hyperbolic orbit says it comes from far beyond.”

 

“We are continuing to observe this unique object,” added Hainaut, “and we hope to more accurately pin down where it came from and where it is going next on its tour of the galaxy. And now that we have found the first interstellar rock, we are getting ready for the next ones!”

 

Astronomers estimate that an interstellar asteroid similar to `Oumuamua passes inside the orbit of Earth several times year, but they are faint and hard to spot, so they have been missed up until now. It is only recently that survey telescopes, such as Pan-STARRS, are powerful enough to have a chance to discover them. “Our successful follow-up observations are a model for the future – especially when the next major survey telescope, LSST, comes on line,” added Meech.

Gemini South telescope color composite image of `Oumuamua (center).

Gemini South telescope color composite image of `Oumuamua (center).

For more on this discovery, and for images read IfA’s news release.

Nov 2 17

November Sky Watch: Using the Star Compass in Oceanic Wayfinding

by Imiloa Astronomy Center

By Chad Kālepa Baybayan & Emily Peavy, ‘Imiloa Astronomy Center of Hawai‛i

Using the Star Compass in Oceanic Wayfinding

In our first Skywatch column last month, we discussed how an ability to read the night sky contributes to the three essential functions of oceanic wayfinding: (1) orienting the direction of a vessel, (2) determining the vessel’s position at sea, and (3) making a successful landfall. Today we will further explore the Star Compass, the tool used by modern navigators on traditional sailing canoes such as the Hōkūle‘a.

The Star Compass is designed as a circle whose edge represents the visual horizon, where the sky touches the land or the sea. To use it, you position yourself in the center of the circle, and begin by establishing the first two cardinal directions: Hikina, east, for the arriving horizon, and Komohana, west, for the entering horizon. With your back to Hikina, your body faces Komohana, and if you extend both arms from the sides of your body, your right arm points toward ‘Ākau, meaning north and right, and your left arm toward Hema, meaning south and left. With Hikina-Komohana and ‘Ākau-Hema intersecting at 90˚ angles, the circle is thus divided into four quadrants.

Each quadrant is named for the winds that typically blow from that quarter. Between north and east is the quadrant Ko’olau; between east and south is the quadrant Malanai; between south and west is the quadrant Kona; and between west and north is the quadrant Ho’olua. Seven houses between each of the four cardinal directions divide the circle evenly. Beginning from either side of Hikina and Komohana and moving towards ʻAkau and Hema are the houses Lā, ʻĀina, Noio, Manu, Nālani, Nāleo, and Haka.

The star compass works like a mirror with the Hikina side reflecting the Komohana side. It also reflects across the quadrant, so Koʻolau reflects with Kona and Malanai reflects with Hoʻolua, and vice versa. The compass works this way: if a star rises in the house called ʻĀina Koʻolau, it climbs out of the arriving horizon, Hikina, arcs upwards until it crosses the meridian (the imaginary line that runs between ʻĀkau and Hema) and begins its descent towards the entering horizon, Komohana, before re-entering the horizon in the same house it arose, ʻAina Hoʻolua, only on the opposite side of the compass.

As objects viewed from the perspective of earth, stars are identified with the hemisphere in which they rise and set and move in parallel tracks across the compass. Stars rising from the northern hemisphere set in the northern hemisphere. In the same manner, wind and swell patterns can be envisioned as moving from quadrant to opposite quadrant in the same hemisphere within the star compass. If a swell or wind moves into the compass from the house Manu Koʻolau, it raverse the center of the compass and exits the opposite quadrant in the house Manu Kona.

The beauty of the Star Compass is its natural symmetry and reflective quality, allowing the navigator to use nature’s clues to determine direction.

 

Evening Observing

Through November the sun will set around 5:40 pm, and it will be completely dark by 7pm, a ripe time for astronomical observations. At dusk, several planets start to become visible. As the closest planet to the Sun, Mercury will always set just after the Sun has set, so throughout the month you can catch a glimpse of Mercury during dusk as it appears to chase the Sun into the western sky. On November 23rd, Mercury will be at a position known as greatest eastern elongation, marking its furthest position from the sun in our sky. This will be the best night to view Mercury, though it will still be faint and setting at 7 pm.

In the west, just after sunset, you can see the ringed planet, Saturn, as it sets early in the evening (by mid-November it will set just before 8 pm). Saturn often appears to be a bit faint in our sky, but it will still be one of the first objects to become visible at nightfall. A small telescope will enable you to catch a glimpse of Saturn’s distinctive rings.

 

Through mid-to-late November, the spectacular Leonid meteor shower will scatter our sky with shooting stars. The Leonids are debris from the tail of the comet Tempel-Tuttle, a periodic comet which last swept through Earth’s orbit in 1998. The peak of the shower will occur on Friday, November 17th, when you should be able to see at least 10-15 meteors each hour.

Rising in the East will be the distinctive star cluster of Makaliʻi, or the Pleiades. This stellar open cluster stands out with its 7 brightest stars clearly visible to the naked eye. The stars in the cluster were all born from the same nebula about 100 million years ago. As these stars are around the same age, the cluster can be used as a laboratory for the study of stellar evolution.  Makaliʻi is also used as a marker for the Makahiki season, the fall harvest celebration in the Hawaiian calendar when the chiefly class collected tribute from local communities and athletic competitions took place.

 

Early Morning Observing

Early risers will get a different perspective of the sky.  Since the sun rises at 6:30am the sky will still be mostly dark until about 6am. Look for the rusty red planet, Mars, as it rises in the East at about 4am. The red color of Mars makes it stand out against the background of stars; Mars gets its red color from the iron-oxide present in its soil.

Just before the sun rises, the bright shape Kaheiheionākeiki (Child’s Cat’s Cradle), which shares the same stars as Orion the Hunter, will be visible in the western sky. The first star to rise in Orionʻs belt, also known as Nākao, is Melemele (Mintaka); it rises exactly east and is used as a marker for the Star Compass house of Hikina. Beneath Nākao, observers can look for the gray fuzziness of the famous Orion Nebula.

 

Moon Phases for November

Full Moon: 7:23 pm HST, Friday, November 3rd

Last Quarter Moon: 10:37 am HST, Friday, November 10th

New Moon: 1:42am HST, Saturday, November 18th

First Quarter Moon: 7:03 am HST, Sunday, November 26th

The Moon’s phase is determined by its position in relation to the Sun and the Earth. The designations of Full, Last Quarter, New and First Quarter refer to specific orientations of the Moon, Sun and Earth. Listed above are the exact times the Moon will be in the precise orientation; however the Moon will not necessarily be visible in Hawai‘i’s sky at the specific time.  As the Moon is incredibly bright in the sky, the best time to do stargazing without its interference will be the week around New Moon (November 18th).

Chad KālepaBaybayan (kbaybayan@imiloahawaii.org) serves as Navigator-in-Residence and Emily Peavy (epeavy@imiloahawaii.org) as Planetarium Technician Support Facilitator.

 

Oct 16 17

UKIRT and the Amazing TRAPPIST-1 Exoplanet System

by Brea Aamoth

‘Imiloa presents Dr. Bob McLaren, Director at UKIRT Observatory
Date: Fri. Nov. 17
Time: 7:00 p.m.
Cost: $10, $8 for members (member level discounts apply)

Hilo, Hawai‘i – UKIRT Observatory on Maunakea is currently studying a fascinating system of small planets that are orbiting a nearby cool red star called TRAPPIST-1. Three of these planets are considered to be in the habitable zone, where conditions would allow liquid water to exist on the surface and potentially allow for life to exist. Learn more about this quest for knowledge at ‘Imiloa’s Maunakea Skies talk on Friday, November 17 at 7:00 p.m. with Dr. Bob McLaren, Director at UKIRT Observatory.

 

Originally known as the United Kingdom Infrared Telescope, UKIRT is now operated by the University of Hawai‘i’s Institute for Astronomy. With its 3.8-meter primary mirror, UKIRT is the largest telescope in the Northern Hemisphere dedicated solely to infrared astronomy. TRAPPIST-1 is very nearby– only 40 light years away. It is classified as an M8 dwarf, which means that it has a mass of about 8 percent that of our Sun and a size only slightly larger than Jupiter.

 

Artists Abstract Conception of TRAPPIST01 System. Photo credit jpl.nasa.gov

A total of seven planets have been discovered around TRAPPIST-1 by using the transit technique, in which astronomers carefully measure the small dimming that occurs when one or more of the planets crosses in front of the star. With its sensitive infrared camera called the Wide Field Cam (WFCAM), UKIRT is able to measure the transit dimming with a photometric accuracy of 500 parts per million and a timing accuracy of 20 seconds. Dr. McLaren will describe how UKIRT’s observations have played a major role in establishing the amazing multi-planet nature of the TRAPPIST-1 system. He will also explain how these same observations have revealed that all seven planets have masses close to that of Earth.

 

Dr. McLaren obtained his Ph.D in Physics from the University of Toronto, Canada in 1973. He worked at the Canada-France-Hawaii Telescope (CFHT) and served three years as CFHT Executive Director just prior to joining the University of Hawai‘i. He was Associate Director at the University of Hawai‘i Institute for Astronomy from 1990 until March 2017. His main work was the implementation of the University’s plan for astronomy development on Maunakea, including the permitting and other local arrangements for the Keck-2, Subaru, Gemini and Submillimeter Array facilities. Over the past decade he has utilized much of his time on site testing, planning and permitting for the Thirty Meter Telescope. He has taught introductory astronomy courses at both the University of Hawai‘i and University of Toronto.

 

Hosted by Planetarium Technician Emily Peavy,‘Imiloa’s monthly Maunakea Skies program includes observational highlights of the current night sky over Hawai‘i, with the audience able to view prominent constellations and stars visible during this time of year. Maunakea Skies planetarium presentations are held on the third Friday of each month. General admission tickets are $10, $8 for ‘Imiloa members (member level discounts apply). Pre-purchase tickets at ‘Imiloa’s front desk or by phone at 808-932-8901.

About ‘Imiloa Astronomy Center:
The ‘Imiloa Astronomy Center of Hawai‘i is a world-class center for informal science education located on the University of Hawai‘i at Hilo campus. Its centerpiece is a 12,000 sq. ft. exhibit hall, showcasing astronomy and Hawaiian culture as parallel journeys of human exploration guided by the light of the stars. The visitor experience is amplified with programming using ‘Imiloa’s full dome planetarium and 9 acres of native landscape gardens. The center welcomes approximately 100,000 visitors each year, including 10,000+ schoolchildren on guided field trips and other educational programs. ‘Imiloa is located at 600 ‘Imiloa Place in Hilo, off of Komohana and Nowelo Streets at the UH Hilo Science and Technology Park. For more information, visit www.ImiloaHawaii.org or call 808- 932-8901.

 

Oct 2 17

The Great American Eclipse of 2017

by Brea Aamoth

‘Imiloa presents John Hamilton, from UH Hilo’s Physics and Astronomy Dept.
Date: Fri. Oct. 20
Time: 7:00 p.m.
Cost: $10, $8 for members (member level discounts apply)

Over 215 million people looked up to the sky to watch the moon’s shadow cut across the continental United States in the Great American Eclipse on August 21, 2017. But what happens during an eclipse? How often do they occur? When can we expect to experience such an eclipse here in Hawai‘i? Learn more about Hawai‘i’s past and future eclipses at ‘Imiloa’s Maunakea Skies talk with John Hamilton from UH Hilo’s Physics and Astronomy Department, on Friday, October 20 at 7:00 p.m.

 

The entirety of North America was able to view at least a partial eclipse this past August. The path of totality covered about 16 percent of the contiguous United States, stretching from Salem, Oregon to Charleston, South Carolina in an event that won’t occur again until August 2045. UH Hilo’s Eclipse Expedition team took advantage of this historical, astronomical event and traveled to the Lost River Field Station in Mackay, Idaho, to obtain one of the best views possible of the total solar eclipse.

 

Hamilton will share his team’s total solar eclipse experience in Idaho, and also discuss the previous solar eclipse that was partially visible in Hawai‘i in July 1991. Will Hawai‘i ever see a total solar eclipse, nature’s spectacular event when the moon comes between the Sun and Earth, casting the darkest part of its shadow on Earth? Come to this Maunakea Skies talk at ‘Imiloa to find out!

 

Hamilton received his BA in Physics and Astronomy from The University of Texas, and his MS in Astronomy from UH Mānoa. Following his schooling, he worked at the NASA Infrared Telescope Facility, Canada-France-Hawaii Telescope and Gemini Observatory on Maunakea. He has taught over 27 distinct courses in the UH Hilo Astronomy and Physics Department, including special topics on Space Exploration. He served as department chair in 2006, and has received three NASA Group Achievement Awards and several NASA Certificates of Appreciation for Mars analog work on Maunakea. He was recently awarded the 2017 UH System Frances David Award for Excellence.

 

Hosted by Planetarium Technician Emily Peavy,‘Imiloa’s monthly Maunakea Skies program includes observational highlights of the current night sky over Hawai‘i, with the audience viewing prominent constellations and stars visible during this time of year. Maunakea Skies planetarium presentations are held on the third Friday of each month. General admission tickets are $10, $8 for members (member level discounts apply). Pre-purchase tickets at ‘Imiloa’s front desk or by phone at 808-932-8901.

Sep 29 17

Our Home Laniakea, The Supercluster of Galaxies

by Brea Aamoth

Galaxies are often described as giant cities, each containing hundreds of billions of stars. While our Milky Way galaxy is massive, it’s still a smaller piece of a much grander structure within our universe. Superclusters are supermassive structures within which thousands of galaxies are connected together by gravity. Dr. Brent Tully, astronomer at the Institute for Astronomy (IfA) helped identify the supercluster “Laniakea,” which means “immense heavens” in Hawaiian, and is home to our Milky Way galaxy. Join us at ‘Imiloa as Dr. Tully discusses Our Home Laniakea, The Supercluster of Galaxies on Friday, October 13 at 7:00 p.m.

A digital map representing the Laniakea Supercluster

A digital map representing the Laniakea Supercluster

Dr. Tully will reveal the complexities of galaxies and how they group themselves throughout our universe. Galaxies are not just distributed randomly, instead they’re found in groups that contain dozens of galaxies that are all interconnected in a web of filaments, in which the galaxies are strung like pearls. The discovery of superclusters has clarified the boundaries of our galactic neighborhood, and establishes previously unrecognized linkages among various galaxy clusters in the local universe. Learn how researchers are finding new ways of evaluating these large-scaled structures by examining their impact on motion, the consequences of a ‘gravitational tug-of-war’.

Tully led the international team of astronomers in defining the contours of the Laniakea supercluster. The name was suggested by Nawa‘a Napolean, an associate professor of Hawaiian Language and chair of the Department of Languages, Linguistics and Literature at Kapiolani Community College, a part of the University of Hawai‘i system. The name honors Polynesian navigators who used their knowledge of the heavens to voyage across the Pacific Ocean.

Nawa‘a Napolean (left) and Dr. Tully (right)

Nawa‘a Napolean (left) and Dr. Tully (right)

Dr. Tully grew up in Vancouver, Canada. He obtained a PhD in astronomy from the University of Maryland in 1972. After taking a year off to see the world, he accepted a postdoctoral position in Marseille, France for two years. In 1975 he accepted a faculty position at the University of Hawai‘i at Mānoa, where he has remained for 42 years. Tully has received several local, national and international awards, among them the ViKtor Ambartsumian International Prize and the Gruber Cosmology Prize.

Dr. Tully’s talk will take place in ‘Imiloa’s planetarium. Tickets are $10, $8 for ‘Imiloa members. Member level discounts apply.

 

About the Institute for Astronomy (IfA):
Founded in 1967, the Institute for Astronomy at the University of Hawai‘i conducts research into galaxies, cosmology, stars, planets and the sun. Its faculty and staff are involved in astronomy education, deep space missions and in the developmental management of the observatories on Maunakea and Haleakalā. IfA operates facilities on the islands of Hawai‘i, O‘ahu, and Maui.