Since the early 20th century, astronomers have found the universe is far larger and more complex than previously thought. The moon, planets and typical deep sky objects are fascinating.  For a view of leading edge astronomy, there are objects that illustrate extreme physics and the hidden history of the universe.  An amateur astronomer can view some of these objects, though the faintest require a powerful telescope and dark skies.

1. You can’t see a black hole, but you can view visible objects influenced by black holes. One easily visible is V Puppis,  a very close binary system stars eclipsing a black hole. You will need to do photometry and track the brightness over time to determine the subtle changes cause by the invisible but massive black hole.

2. Neutron stars were first discovered from their regular pulsing radio emissions (hence named “pulsars”).  They for through the collapse of s supergiant star.  The Crab Nebula (M1)  contains a neutron star at it core.  The Crab Nebula formed as the result of a supernova explosion in 1054.  Chinese astronomers recorded the explosion.  The actual neutron star has a magnitude of only 16.5 making it very challenging for an amateur astronomer.  An amateur radio telescope might be able to detect this pulsar as it is among the brightest radio sources in the sky. The Crab Nebula is right by souther “horn” of Taurus the bull.

2. Messier 54, the first globular cluster found to be outside our galaxy. Messier 54 belongs to a satellite of the Milky Way called the Sagittarius Dwarf Elliptical Galaxy. The Milky Way is in the process of swallowing this smaller galaxy, making it the most recent of the Milky Way’s mergers.

3. A galaxy called the Gaia Sausage merged with the Milky Way 8 to 11 billion years ago.  The end result of this was to thicken the Milky Way’s disk. Remnants of the Gaia Sausage include the following Messier globular clusters : M2 in Aquarius, M56 in Lyra, M75 in Sagittarius, and M79 in Lepus .

4. Kraken was another galaxy which merged with the Milky Way, 11 billion years ago. The most likely candidate according to one publication is NGC 6273 (M19) in Ophiuchus.

5. Finally, the Helmi stream is another remnant of a dwarf galaxy swallowed by the Milky Way. perhaps about 10 billion years ago. The most likely candidate according to one publication is NGC 6934 in Delphinus.

6. Seyfert Galaxies have a quasar-like nucleus but unlike true quasars are very bright in the visible spectrum.  Like quasars, they are powered by black holes at the center of the galaxy. The following Seyfert Galaxies are easily viewable Messier objects: M51a in Canes Venatici, M64 in Coma Berenices, M66 in Leo, M77 in Cetus, M81 in Ursa Major, M88 in Coma Berenices, and M106 in Canes Venatici.

7. Quasars are distant galaxies powered by super-massive black holes.  The black holes generate enormous amounts of radio emissions, however they are very faint in visual light. Quasar 3C 273 in Virgo at magnitude 12.9 is the brightest one visible from earth.