The Perseus Arm is one of two major spiral arms of the Milky Way galaxy. The second major arm is called the Scutum–Centaurus Arm. The Perseus Arm begins from the distal end of the long Milky Way central bar.[1] Previously thought to be 13,000 light-years away, it is now thought to lie 6,400 light years from the Solar System.[2]
Observed structure of the Milky Way's spiral arms.
Recently, scientists in two large radio astronomy projects, the Bar and Spiral Structure Legacy (BeSSeL) Survey and the Japanese VLBI Exploration of Radio Astrometry (VERA), have made great efforts about 20 years to measure the trigonometric parallaxes toward about 200 water vapor (H 2O) and methanol (CH 3OH) masers in massive star-forming regions in the Milky Way. They have employed these parallax measurements to delineate the forms of spiral arms from the Galactic longitude 2 to 240 degrees and extended the spiral arm traces into the portion of the Milky Way seen from the Southern Hemisphere using tangencies along some arms based on carbon monoxide emission. The image clearly presents the Milky Way as a barred spiral galaxy with fairly symmetric four major arms and some extra arm segments and spurs.[3][4]
The Perseus Arm is one of the four major arms. The arm is the length of more than 60,000 lr and the width of about 1,000 lr and the spiral extension in the pitch angle near 9 degree.[3]
There is speculation that the local spur known as the Orion–Cygnus Arm, which includes the Solar System and Earth and is located inside of the Perseus Arm,[1] is a branch of it, but this is unconfirmed.
^ abcdChurchwell, Ed; Babler, Brian L.; Meade, Marlin A. (2009). "The Spitzer/GLIMPSE Surveys: A New View of the Milky Way" (pdf). Publications of the Astronomical Society of the Pacific. 121: 213–230. Bibcode:2009PASP..121..213C. doi:10.1086/597811.
^McKee, Maggie (8 December 2005). "Spiral arm of Milky Way looms closer than thought". New Scientist. Reed Business Information Ltd. Retrieved 31 October 2013.
^ abReid, M. J.; et al. (2009). "Trigonometric parallaxes of massive star-forming regions. VI. Galactic structure, fundamental parameters, and noncircular motions". The Astrophysical Journal. 700 (1): 137–148. arXiv:0902.3913. Bibcode:2009ApJ...700..137R. doi:10.1088/0004-637X/700/1/137. S2CID 11347166.
^Hirota, Tomoya; et al. (2020). "The First VERA Astrometry Catalog". Publications of the Astronomical Society of Japan. 72 (4). arXiv:2002.03089. doi:10.1093/pasj/psaa018.
perseus, major, spiral, arms, milky, galaxy, second, major, called, scutum, centaurus, begins, from, distal, long, milky, central, previously, thought, light, years, away, thought, light, years, from, solar, system, observed, structure, milky, spiral, arms, co. The Perseus Arm is one of two major spiral arms of the Milky Way galaxy The second major arm is called the Scutum Centaurus Arm The Perseus Arm begins from the distal end of the long Milky Way central bar 1 Previously thought to be 13 000 light years away it is now thought to lie 6 400 light years from the Solar System 2 Observed structure of the Milky Way s spiral arms Contents 1 Overview 2 See also 3 References 4 External linksOverview editThe Milky Way is a barred spiral galaxy with two major arms and a number of minor arms or spurs 1 The Perseus Spiral Arm with a radius of approximately 10 7 kiloparsecs is located between the minor Cygnus and Carina Sagittarius Arms 1 It is named after the Perseus constellation in the direction of which it is seen from Earth Recently scientists in two large radio astronomy projects the Bar and Spiral Structure Legacy BeSSeL Survey and the Japanese VLBI Exploration of Radio Astrometry VERA have made great efforts about 20 years to measure the trigonometric parallaxes toward about 200 water vapor H2 O and methanol CH3 OH masers in massive star forming regions in the Milky Way They have employed these parallax measurements to delineate the forms of spiral arms from the Galactic longitude 2 to 240 degrees and extended the spiral arm traces into the portion of the Milky Way seen from the Southern Hemisphere using tangencies along some arms based on carbon monoxide emission The image clearly presents the Milky Way as a barred spiral galaxy with fairly symmetric four major arms and some extra arm segments and spurs 3 4 The Perseus Arm is one of the four major arms The arm is the length of more than 60 000 lr and the width of about 1 000 lr and the spiral extension in the pitch angle near 9 degree 3 There is speculation that the local spur known as the Orion Cygnus Arm which includes the Solar System and Earth and is located inside of the Perseus Arm 1 is a branch of it but this is unconfirmed The Perseus Arm contains the Double Cluster and a number of Messier objects The Crab Nebula M1 Open Cluster M36 Open Cluster M37 Open Cluster M38 Open Cluster M52 Open Cluster M103 See also editGalactic disc List of Messier objectsReferences edit a b c d Churchwell Ed Babler Brian L Meade Marlin A 2009 The Spitzer GLIMPSE Surveys A New View of the Milky Way pdf Publications of the Astronomical Society of the Pacific 121 213 230 Bibcode 2009PASP 121 213C doi 10 1086 597811 McKee Maggie 8 December 2005 Spiral arm of Milky Way looms closer than thought New Scientist Reed Business Information Ltd Retrieved 31 October 2013 a b Reid M J et al 2009 Trigonometric parallaxes of massive star forming regions VI Galactic structure fundamental parameters and noncircular motions The Astrophysical Journal 700 1 137 148 arXiv 0902 3913 Bibcode 2009ApJ 700 137R doi 10 1088 0004 637X 700 1 137 S2CID 11347166 Hirota Tomoya et al 2020 The First VERA Astrometry Catalog Publications of the Astronomical Society of Japan 72 4 arXiv 2002 03089 doi 10 1093 pasj psaa018 External links editMessier Objects in the Milky Way Galaxy SEDS Portals nbsp Stars nbsp Spaceflight nbsp Outer space nbsp Solar System Retrieved from https en wikipedia org w index php title Perseus Arm amp oldid 1174967172, wikipedia, wiki, book, books, library,
