Myanmar Christens Star ‘Ayeyarwady’ and Planet ‘Bagan’

By Nyein Nyein 9 January 2020

A planet and a star 553 light-years away from Earth have been officially named after Bagan, the ancient Myanmar city and UNESCO World Heritage Site, and the Ayeyarwady, Myanmar’s largest river. This is the first time that Myanmar has named a star or a planet.

The International Astronomical Union (IAU), which governs all official naming of stars and planets, launched a contest last year called NameExoWorlds to commemorate its 100 year anniversary. From June to November, 112 participating countries each ran their own competitions to nominate names for one planet and its host star.

A giant gas planet, HD 18742 b, is now named Bagan. / exoplanets.nasa.gov

According to the IAU, astronomers have recently been discovering thousands of planets and solar systems around nearby stars. Scientists now say that each star in the universe may have one or multiple planets in its orbit, some of which may even have physical characteristics that resemble the Earth. 

In December, the IAU selected 112 stars, each with one exoplanet—the term for a planet outside our solar system. The IAU then allotted each participating country or region a star that can be seen from that country with a small telescope.

Myanmar’s exoplanet, Bagan, revolves around HD18742, a gas giant which is now named Ayeyarwady. The exoplanet has a mass 3.4 times that of Jupiter and takes over two years to complete an orbit of Ayeyarwady. They were discovered in 2011 in the constellation Eridanus, according to the Myanmar Astronomy and Science Enthusiasts Society (MASES).

A yellow star, HD 18742, is now named Ayeyarwady. / exoplanets.nasa.gov

MASES organized the country’s national campaign together with physicists from Yangon University’s Physics Department, according to Ko Boothee Thaik Htun, one of the founders of MASES. The society was founded by amateur astronomers in 2004 and has been in cooperation with the IAU since 2008.

“Such recognition is the first ever in Myanmar history,” said Ko Boothee Thaik Htun, who helped organize the national campaign to choose names for the star and planet that reflect local cultures, traditions, values or geography in Myanmar.

“We had public voting on nine names that represented key aspects of geographical and culture identity and the pair—Ayeyarwady and Bagan—won the most votes, he added. “But we had other names too. We sent all the names to the IAU, explaining the significance of each name. [Ayeyarwady and Bagan] were chosen because the IAU shares the view that these names are meaningful and good for future astronomical references and it will be useful to the spread of astronomical knowledge among the public [by linking them to local identity].”

A screenshot of the visualization of planet Bagan (HD 18742 b) orbiting star Ayeyarwady (HD 18742). /exoplanets.nasa.gov

Ko Boothee Thaik Htun, who started as an amateur astronomer, and other like-minded people often gather to stargaze, share knowledge with young students and participate in global and regional astronomy camps and events. He said they will be looking at the star Ayeyarwady and planet Bagan during their regular stargazing nights.

MASES will host a stargazing night later this month in Yangon, or next month in Mandalay after an event with Mandalay University.

The IAU said that over 780,000 people participated in the national campaigns in 112 countries for NameExoWorlds. The aim of the project was to “contribute to the fraternity of all the people with a significant token of global identity.”

Six other Southeast Asian nations—Brunei, Indonesia, Malaysia, the Philippines, Singapore and Thailand—also had the chance to name stars and planets through the IAU. Their nominations for names range from words for precious gems—Malaysia’s “Baiduri” and “Intan”—to traditional gods—the Philippines’ “Aman Sinaya” and “Haik.” Thailand named both a star and its planet after rivers—the Chao Phraya and the Mae Ping.