Spot the Andromeda Galaxy Overhead This Week

[Judi Lynn]

By Joe Rao, Space.com Skywatching Columnist | November 23, 2018 08:21am ET

The most distant object in space that we can see with our unaided eyes, the Andromeda Galaxy, is located more than 2 million light-years away — but you can see it in the early evening night sky this autumn.

Step outside this week and look high overhead at around 8:30 p.m. local time, and you'll be able to sight what is without a doubt the most famous galaxy in all of our sky, M31, in the constellation Andromeda — an object that nearly a century ago helped extend our perspective of the cosmos as nothing else has ever done.

As recently as the early 1900s, astronomers quarreled about whether this and other spiral "nebulas" were part of our own system of stars, which we call the Milky Way, or if they were "island universes" — that is, independent stellar systems of their own. [Seeing the Best Night-Sky Sights of Autumn Using Mobile Apps]

Tremendous controversy
In an attempt to settle this issue once and for all, on April 26, 1920, two leading astronomers of the day, Harlow Shapley and Heber D. Curtis, squared off at the Smithsonian Museum of Natural History in Washington, D.C., in what has since become known as "The Great Debate." At the time, Shapley — who ultimately went on to become one of the 20th century's greatest extragalactic experts — incorrectly argued that these spiral "nebulas" were part of our own stellar system. He was led astray by Adriaan Van Maanen, an astronomer working at the Mount Wilson Observatory, who measured the distances of stellar objects using parallax. For example, when we measure the position of a star from two diametrically opposite locations along our orbit, the apparent difference in the star's position — however slight — can provide us with a fairly accurate value that reveals how far away the star is from us.

More:
https://www.space.com/42507-andromeda-galaxy-overhead-this-week.html

[NRaleighLiberal]

1. It is easier to see using averted vision - kind of at the side of your vision - than looking

directly at it. It is a large object but the light is very diffuse - if you look just slightly off of overhead try to sense a gauzy patch of light, that's it! Amazing to think it is a complete galaxy - countless stars and planets. Makes one feel very, very very tiny and insignificant (which is a good thing, in my opinion!)

[Judi Lynn]

2. Tell it to the pResident, NRaleighLiberal! How much time do you think he'd spend looking for it?

He might possible insist he just discovered it.

It sounds as if you have spent quality time becoming acquainted with serious searching.

Have never heard instructions, suggestions explained this way. It would encourage anyone with access to a telescope to get right out there.

Thank you for your thoughtful explanation.

[NRaleighLiberal]

3. Hey there! I've been an astronomy buff since - 10 years old, maybe - had a telescope

at one time. It is easy to demonstrate the averted vision thing when looking at a cluster like the Pleiades (in Taurus) - you can actually see more stars in it by looking slightly to the side of it than by staring straight at it.


This is a pretty good explanation https://en.wikipedia.org/wiki/Averted_vision


See - not only heirloom tomatoes for me!

Thanks for always posting the most fascinating things here at DU - I look forward to your contributions daily!

[eppur_se_muova]

4. The Triangulum Galaxy (3 Mly) and Bode's Galaxy (12 Mly) are also visible under the best conditions.

Messier 81 is located approximately 10° northwest of Alpha Ursae Majoris along with several other galaxies in the Messier 81 Group.[6][22] Messier 81 and Messier 82 can both be viewed easily using binoculars and small telescopes.[6][22] The two objects are generally not observable to the unaided eye, although highly experienced amateur astronomers may be able to see Messier 81 under exceptional observing conditions with a very dark sky.[6] Telescopes with apertures of 8 inches (20 cm) or larger are needed to distinguish structures in the galaxy.[22] Its far northern declination makes it generally visible for observers in the northern hemisphere. It is not visible to most observers in the southern hemisphere, except those in a narrow latitude range immediately south of the equator.

https://en.wikipedia.org/wiki/Messier_81#Amateur_astronomy

Under exceptionally good viewing conditions with no light pollution, the Triangulum Galaxy can be seen with the naked eye.[14] It is one of the most distant permanent objects that can be viewed without the aid of a telescope.[15][16] Being a diffuse object, its visibility is strongly affected by small amounts of light pollution. It ranges from easily visible by direct vision in dark skies to a difficult averted vision object in rural or suburban skies.[14] For this reason, Triangulum is one of the critical sky marks of the Bortle Dark-Sky Scale.[17]

https://en.wikipedia.org/wiki/Triangulum_Galaxy#Visibility

[Judi Lynn]

5. The images at these links are overwhelming.

An infrared image of Messier 81 taken by the Spitzer Space Telescope.



Triangulum Galaxy – Messier 33



NGC 604 in the Triangulum Galaxy

Words fail.

Thank you.