After working on my Newtonian Reflector Project for over half a year, I finally have my Telescope ready, it is a newtonian reflector, 16" of diameter, focal ratio f/4. The mirror is purchased used, but the quality is pretty good, 12th wave, Strehl ratio .96. So I decide to start my Messier marathon.
First goal, M1 crab nebula
The Crab Nebula is a supernova remnant. Embedded within it is a radio pulsar.
- The supernova was observed in 1054 A.D. by Chinese
- The supernova event was visible to the naked eye in the daytime; it was as bright as Venus.
- The filaments in the nebula are seen to be expanding at 1000 km/sec.
- The total mass of ejected material is about 0.1 solar masses.
- The distance to the Crab Nebula is about 6500 light years.
- The diameter of the remnant is 6 light years.
- A pulsar was discovered in the center of the nebula in 1969.
- The neutron star in the center of the Crab rotates 33 times per second.
- Since it expands at speed of 600 miles in a sec., it grows 1 arcsec every five years, so during Messier time, it was more brighter!
Sounds interesting, yesterday, I see its face!
How? First find Constellation Taurus, it is close to zenith in winter evening, the alpha (Aldebaran) is a orange star (ranging bull), the zeta star is at end of its left horn, it is above Orion's head, going north from zeta star about 2 degree is the M1 crab nebula.
The field angle with my telescope is about 1 degree, so I just need to do star hopping from zeta star.
The hopping path zeta tau -> 77308 -> 77293 -> 77269 -> M1.
Finally, this is what I saw in eyepiece
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