{"id":46221,"date":"2023-06-12T11:56:38","date_gmt":"2023-06-12T11:56:38","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=119336"},"modified":"2023-06-12T12:32:29","modified_gmt":"2023-06-12T12:32:29","slug":"see-star-edasich-host-of-the-first-exoplanet-found-orbiting-a-giant-star","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/see-star-edasich-host-of-the-first-exoplanet-found-orbiting-a-giant-star\/","title":{"rendered":"See star Edasich, host of the first exoplanet found orbiting a giant star"},"content":{"rendered":"

Edasich is an orange K-type giant star embedded in the tail of Draco, the Dragon. <\/p>

By Pete Lawrence\n \t\t<\/p>

Published: Monday, 12 June 2023 at 12:00 am<\/p>

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Edasich (Iota (\u03b9) Draconis) is a mag. +3.3 star in the curving tail of Draco, the Dragon.<\/p>\n

Located 31.8\u00b0 from Polaris (Alpha (\u03b1) Ursae Minoris), Edasich is circumpolar from the UK and never sets.<\/p>\n

The name is a corruption of the Arabic term for \u2018the male hyena\u2019.<\/p>\n

The Chinese name for Edasich is Z\u012d W\u0113i Zu\u014f Yu\u00e1n y\u012b, which means \u2018First Star of Left Wall of Purple Forbidden Enclosure\u2019, the enclosure asterism<\/a> being formed by Iota, Theta (\u03b8<\/span>), Eta (\u03b7<\/span>), Zeta (\u03b6), Upsilon (\u03c5<\/span>), 73, Gamma (\u03b3) and Beta (\u03b2) Draconis.<\/p>\n

Edasich is 1.8 times more massive, 12 times larger and 55 times more luminous than our own Sun.<\/p>\n

It has a spectral classification<\/a> of K2 III, indicating that it\u2019s an orange giant star.<\/p>\n

Edasich is estimated to be about 1.2 billion years old and, like our own Sun, rotates slowly with a speed of 1.5km\/s.<\/p>\n

Edasich gave rise to the first exoplanet<\/a> discovered to orbit a giant star.<\/p>\n

The discovery, made in 2002, was interesting because the habitable zone for a giant is large, giving a reasonable chance that a planet would sit within it.<\/p>\n

Edasich\u2019s habitable zone extends 6.8\u201313.5 AU and the exoplanet (Edasich-b, named Hypatia) orbits with a semi-major axis of 1.45 AU, placing it too close to the parent star.<\/p>\n

Edasich-c, discovered in 2021, lies outside the habitable range, with an orbital semi-major axis distance of 19.4 AU.<\/p>\n

Infrared<\/a> excess from the system suggests the presence of a circumstellar debris disc in orbit around the star.<\/p>\n

This guide originally appeared in the June 2023 issue of BBC Sky at Night Magazine.<\/strong><\/em><\/p> <\/body><\/html>\n