[15], Its traditional name Antares derives from the Ancient Greek Ἀντάρης,[16] meaning "rival to-Ares" ("opponent to-Mars"), due to the similarity of its reddish hue to the appearance of the planet Mars. It is the brightest star in the constellation and the 15th brightest in Earth’s night sky. Recently, astronomers released a new study on Antares, which was published in the journal Astronomy and Astrophysics. Fixed star Antares represents one of the important four Archangels stars. For two to three weeks on either side of November 30 Antares is not visible in the night sky, because it is near conjunction with the Sun. The heat on the inside is the reason the star’s outside is so cool. [17] The comparison of Antares with Mars may have originated with early Mesopotamian astronomers. [12] It was called tms n hntt "the red one of the prow". Giant and Supergiant Stars - Old, Large Stars RED GIANT The diameter of Antares can be measured most accurately using interferometry or observing lunar occultations events. The linear radius of the star can be calculated from its angular diameter and distance. Antares is a relatively cool star, and it is not its temperature, but its enormous size and relative proximity to Earth that make it appear so bright. 1", "LASCO Star Maps (identify objects in the field of view for any day of the year)", "The Radial Velocity Variations of a Orionis and a Scorpii", "On an Occultation of Antares by the Moon", "Sky watchers report occultation of Antares by moon", https://www.skyandtelescope.com/interactive-sky-chart/, "Dynamical masses of a selected sample of orbital binaries", "Orbits of Seven Edge-On Visual Double Stars", "The 2001 US Naval Observatory Double Star CD-ROM. NASA Spots Star That Survived Companion’s Supernova Blast, This Massive Star Is Creating Spirals In Its Wind, US Companies Altering, Canceling Performance Reviews In Response To Pandemic, ConocoPhillips To Acquire Concho Resources In $9.7 Billion Oil Deal, The Possibilities AND the Pitfalls of Remote Work, 10 Of America's Top CEOs Talk with IBT's Social Capital About How To Be Authentic, Antares is a red supergiant star that's 12 times more massive than the Sun, Astronomers created a map showing the actual size of Antares, Antares has a cooler atmosphere than the Sun. To put its size into perspective, the Sun’s chromosphere is only about 0.5% of its radius. Diameter: Approx 22 million miles (36 million km) - 26 times the Sun. He is Oriel, the watcher of the west. It is now so entered in the IAU Catalog of Star Names.[20]. [12] Some scholars have speculated that the star may have been named after Antar, or Antarah ibn Shaddad, the Arab warrior-hero celebrated in the pre-Islamic poems Mu'allaqat. Antares then rises at dusk and sets at dawn as seen at the equator. The astronomers were able to create the star using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile and the Karl G. Jansky Very Large Array (VLA) of the National Science Foundation in New Mexico. [8] Despite its large size compared to the Sun, Antares is dwarfed by even larger red supergiants, such as VY Canis Majoris or VV Cephei A and Mu Cephei. Higher than 64° northern latitude, the star does not rise at all. Antares is a variable star and is listed in the General Catalogue of Variable Stars but as a Bayer-designated star it does not have a separate variable star designation. There is also considerable variation between values published by different authors, for example 75,900 L☉ and 97,700 L☉ published in 2012 and 2013. It … The brighter of the pair is the red supergiant, while the fainter is a hot main sequence star of magnitude 5.5. α Scorpii (Latinised to Alpha Scorpii) is the star's Bayer designation. The Māori people of New Zealand call Antares Rēhua, and regard it as the chief of all the stars. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from apparent magnitude +0.6 to +1.6. The WGSN's first bulletin of July 2016[19] included a table of the first two batches of names approved by the WGSN, which included Antares for the star α Scorpii A. There is no obvious periodicity, but statistical analyses have suggested periods of 1,733 days or 1650±640 days. : 'fiery star') because of its reddish appearance. Red supergiant star in the constellation Scorpius, This article is about the star. The diameter of the limb-darkened disk was measured as 37.38±0.06 milliarcseconds in 2009 and 37.31±0.09 milliarcseconds in 2010. Antares can also be occulted by the planets, e.g. The astronomers stated that the temperature of Antares’ chromosphere is about 6,400 degrees Fahrenheit, which is significantly cooler than that of the Sun’s at 36,032 degrees Fahrenheit. Through the data collected by ALMA and the VLA, the astronomers were able to create a radio map of the massive star’s atmosphere. [12], In ancient Mesopotamia, Antares may have been known by various names: Urbat, Bilu-sha-ziri ("the Lord of the Seed"), Kak-shisa ("the Creator of Prosperity"), Dar Lugal ("The King"), Masu Sar ("the Hero and the King"), and Kakkab Bir ("the Vermilion Star"). [38] Venus will be extremely near Antares on October 19, 2117 and every eight years thereafter through to October 29, 2157 it will pass south of the star. On 31 July 2009, Antares was occulted by the Moon. An apparent diameter from occultations 41.3 ± 0.1 milliarcseconds has been published. As noted by the astronomers, Antares’ chromosphere is about 2.5 times the red supergiant’s radius. Its large size and relatively small mass give Antares a very low density. Mass: 110% of the Sun. This page was last edited on 22 March 2019, at 08:16. [43], Early measurements of the pair found them to be about 3.5″ apart in 1847–49,[30] or 2.5″ apart in 1848. This is dwarfed by its massive chromosphere, which is a gaseous layer that forms the outer atmosphere and the corona. “The difference can be explained because our radio measurements are a sensitive thermometer for most of the gas and plasma in the star's atmosphere, whereas past optical and ultraviolet observations were only sensitive to very hot gas and plasma,” he continued. With this detailed map, the team found that Antares' chromosphere, a gaseous layer that creates a star's outer atmosphere along with its corona, stretches to 2.5 times the star's radius. It is assumed to be a relatively normal early-B main sequence star with a mass around 7 M ☉ , a temperature around 18,500 K , and a radius of about 5 R ☉ . [2] No separate long secondary period has been detected,[33] although it has been suggested that primary periods longer than a thousand days are analogous to long secondary periods. Antares is a member of the Upper Scorpius subgroup of the association, which contains thousands of stars with a mean age of 11 million years, about 170 parsecs (550 ly) from Earth. [24], Antares was first reported to have a companion star by Johann Tobias Bürg during an occultation on April 13, 1819,[25] although this was not widely accepted and dismissed as a possible atmospheric effect. [40] It describes an almost circular orbit seen nearly edge-on, with a period of 1,218 years and a semi-major axis of about 2.9″. Its exact size remains uncertain, but if placed at the center of the Solar System, it would reach to somewhere between the orbits of Mars and Jupiter. Antares is a massive star that lies in the constellation of Scorpius. [12] In ancient Egypt, Antares represented the scorpion goddess Serket (and was the symbol of Isis in the pyramidal ceremonies). [35][36] Every year around December 2 the Sun passes 5° north of Antares. Betelgeuse, Antares: Subtypes Within each stellar type, stars are placed into subclasses (from 0 to 9) based on its position within the scale. And that jacks up the core’s temperature. The Kulin Kooris saw Antares (Balayang) as the brother of Bunjil (Altair).[59]. The ALMA and VLA map of Antares is the most detailed radio map yet of any star, other than the Sun. [28] More modern observations consistently give separations around 2.6″ – 2.8″. Antares is visible all night around May 31 of each year, when the star is at opposition to the Sun. [23] It became apparent that the small variations could not be due to orbital motion, and were actually caused by pulsation of the star's atmosphere. Even in 1928, it was calculated that the size of the star must vary by about 20%. [57] This had been directly translated from the Ancient Greek Καρδία Σκορπίου Kardia Skorpiū. According to their study, the readings taken by ALMA and the VLA indicated that the chromosphere’s temperature is cooler compared to previous observations.