{"id":677,"date":"2021-08-19T03:02:54","date_gmt":"2021-08-19T03:02:54","guid":{"rendered":"http:\/\/www.lunar.org\/wp\/?p=677"},"modified":"2021-08-19T03:02:54","modified_gmt":"2021-08-19T03:02:54","slug":"catch-andromeda-rising","status":"publish","type":"post","link":"http:\/\/www.lunar.org\/wp\/?p=677","title":{"rendered":"Catch Andromeda Rising"},"content":{"rendered":"

David Prosper\"\"<\/a>
\nNASA JPL<\/p>\n

If you\u2019re thinking of a galaxy, the image in your head is probably the Andromeda Galaxy! Studies of this massive neighboring galaxy, also called M31, have played an incredibly important role in shaping modern astronomy. As a bonus for stargazers, the Andromeda Galaxy is also a beautiful sight.<\/p>\n

<\/p>\n

Have you heard that all the stars you see at night are part of our Milky Way galaxy? While that is mostly true, one star-like object located near the border between the constellations of Andromeda and Cassiopeia appears fuzzy to unaided eyes. That\u2019s because it\u2019s not a star, but the Andromeda Galaxy, its trillion stars appearing to our eyes as a 3.4 magnitude patch of haze. Why so dim? Distance! It\u2019s outside our galaxy, around 2.5 million light years distant – so far away that the light you see left M31\u2019s stars when our earliest ancestors figured out stone tools. Binoculars show more detail: M31\u2019s bright core stands out, along with a bit of its wispy, saucer-shaped disc. Telescopes bring out greater detail but often can\u2019t view the entire galaxy at once. Depending on the quality of your skies and your magnification, you may be able to make out individual globular clusters, structure, and at least two of its orbiting dwarf galaxies: M110 and M32. Light pollution and thin clouds, smoke, or haze will severely hamper observing fainter detail, as they will for any \u201cfaint fuzzy.\u201d Surprisingly, persistent stargazers can still spot M31\u2019s core from areas of moderate light pollution as long as skies are otherwise clear.<\/p>\n

Modern astronomy was greatly shaped by studies of the Andromeda Galaxy. A hundred years ago, the idea that there were other galaxies beside our own was not widely accepted, and so M31 was called the \u201cAndromeda Nebula.\u201d Increasingly detailed observations of M31 caused astronomers to question its place in our universe \u2013 was M31 its own \u201cisland universe,\u201d and not part of our Milky Way? Harlow Shapley and Heber Curtis engaged in the \u201cGreat Debate\u201d of 1920 over its nature. Curtis argued forcefully from his observations of dimmer than expected nova, dust lanes, and other oddities that the \u201cnebula\u201d was in fact an entirely different galaxy from our own. A few years later, Edwin Hubble, building on Henrietta Leavitt\u2019s work on Cepheid variable stars as a \u201cstandard candle\u201d for distance measurement, concluded that M31 was indeed another galaxy after he observed Cepheids in photos of Andromeda, and estimated M31\u2019s distance as far outside our galaxy\u2019s boundaries. And so, the Andromeda Nebula became known as the Andromeda Galaxy.<\/p>\n

These discoveries inspire astronomers to this day, who continue to observe M31 and many other galaxies for hints about the nature of our universe. One of the Hubble Space Telescope\u2019s longest-running observing campaigns was a study of M31: the Panchromatic Hubble Andromeda Treasury (PHAT): bit.ly\/m31phat<\/a> . Dig into NASA\u2019s latest discoveries about the Andromeda Galaxy, and the cosmos at large, at nasa.gov<\/a>.<\/p>\n

\"\"<\/a><\/p>\n

Spot the Andromeda Galaxy! M31\u2019s more common name comes from its parent constellation, which becomes prominent as autumn arrives in the Northern Hemisphere. Surprising amounts of detail can be observed with unaided eyes from dark sky sites. Hints of it can even be made out from light polluted areas. Image created with assistance from Stellarium<\/em><\/p>\n

\"\"<\/a><\/p>\n

While M31\u2019s disc appears larger than you might expect (about 3 Moon widths wide), its \u201cgalactic halo\u201d is much, much larger \u2013 as you can see here. In fact, it is suspected that its halo is so huge that it may already mingle with our Milky Way\u2019s own halo, which makes sense since our galaxies are expected to merge sometime in the next few billion years! The dots are quasars, objects located behind the halo, which are the very energetic cores of distant galaxies powered by black holes at their center. The Hubble team studied the composition of M31\u2019s halo by measuring how the quasars\u2019 light was absorbed by the halo\u2019s material. \u00a0Credits: NASA, ESA, and E. Wheatley (STScI)\u00a0 Source: https:\/\/bit.ly\/m31halo<\/a><\/em><\/p>\n

This article is distributed by NASA Night Sky Network <\/strong><\/p>\n

The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach. Visit nightsky.jpl.nasa.gov<\/a> to find local clubs, events, and more!<\/p>\n","protected":false},"excerpt":{"rendered":"

David Prosper NASA JPL If you\u2019re thinking of a galaxy, the image in your head is probably the Andromeda Galaxy! Studies of this massive neighboring galaxy, also called M31, have played an incredibly important role in shaping modern astronomy. As a bonus for stargazers, the Andromeda Galaxy is also a beautiful sight.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[14],"tags":[],"class_list":["post-677","post","type-post","status-publish","format-standard","hentry","category-nasa-space-place"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=\/wp\/v2\/posts\/677","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=677"}],"version-history":[{"count":1,"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=\/wp\/v2\/posts\/677\/revisions"}],"predecessor-version":[{"id":680,"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=\/wp\/v2\/posts\/677\/revisions\/680"}],"wp:attachment":[{"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=677"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=677"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.lunar.org\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=677"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}