Posted on 11/21/2020 6:24:48 AM PST by BenLurkin
Scientists working with data from the Sloan Digital Sky Surveys’ Apache Point Observatory Galactic Evolution Experiment (APOGEE) have discovered a “fossil galaxy” hidden in the depths of our own Milky Way.
Astronomers named it Heracles...
The remnants of Heracles account for about one third of the Milky Way’s spherical halo. But if stars and gas from Heracles make up such a large percentage of the galactic halo, why didn’t we see it before? The answer lies in its location deep inside the Milky Way.
APOGEE has measured spectra for more than half a million stars all across the Milky Way, including its previously dust-obscured core.
To separate stars belonging to Heracles from those of the original Milky Way, the team made use of both chemical compositions and velocities of stars measured by the APOGEE instrument.
Because galaxies are built through mergers of smaller galaxies across time, the remnants of older galaxies are often spotted in the outer halo of the Milky Way, a huge but very sparse cloud of stars enveloping the main galaxy. But since our Galaxy built up from the inside out, finding the earliest mergers requires looking at the most central parts of the Milky Way’s halo, which are buried deep within the disc and bulge.
Stars originally belonging to Heracles account for roughly one third of the mass of the entire Milky Way halo today – meaning that this newly-discovered ancient collision must have been a major event in the history of our Galaxy.
The fifth phase of the SDSS has already begun taking data, and its “Milky Way Mapper” will build on the success of APOGEE to measure spectra for ten times as many stars in all parts of the Milky Way, using near-infrared light, visible light, and sometimes both.
(Excerpt) Read more at scitechdaily.com ...
I hope the geologists don’t resurrect it.
Any travel which can be accomplished during one adult life span is feasible. Any travel requiring multiple human generations bred inside a space capsule...FUHGETT BOUT IT. I am guessing you never helped deliver your children in a hospital.
Your non-secquator reply indicates you have no idea what I was talking about by persisting with the present limitations as if they apply to the future. Human heavier than air flight was roundly believed impossible until the Wright Bros.
You are a true curmudgeon.
For me, the main problem with Milky Way’s mass is the fact that even after it has been reduced by a factor of 3, the cost has increased by a factor of 3...
As far as the core is concerned, it has all but disappeared into a halo of crappy chemicals...
Don't quit your day job.
LOL I already quit my job after realizing there is no way I could run out of cash if I lived to age 110.
How about you?
lol
:-)
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.