Crab Nebula

[Christopher K.]

Easily one of the best-researched nebula in human history, this object is known throughout the world as Messier 1. Located 67 arcminutes northwest of Zeta Tauri, the nebula remnant was discovered by John Bevis and found independently by Charles Messier in 1758--inspiring him to compile his famous "not a comet" catalog.

Lampland at Lowell Observatory was the first to confirm (in 1921) that the nebula was not static and was in fact growing. The supernova responsible for the Crab was probably that of 4 July 1054, noted by the Chinese, who recorded that the explosion was visible in daylight for over three weeks.

For several decades the Crab Nebula's radiation was thought to be steady. Recent findings by Mike Cherry and Gary Case of LSU (with graduate student James Rodi) have turned that assumption upside down. First noticing the dimming in data from Fermi's Gamma Ray Burst Monitor, the group checked against data from Rossi and Swift to make sure it wasn't an instrument problem. They discovered a two-year decline of seven percent in energies between 15,000 and 50,000 electron volts.

More background information at:
Burnham's Celestial Handbook, pp. 1843-1861
http://seds.org/messier/m/m001.html

More about the X-ray fluctuations:
http://www.nasa.gov/mission_pages/GLAST ... prise.html
http://www.phys.lsu.edu/newwebsite/news ... marayburst
http://apod.nasa.gov/apod/ap110523.html

[Christopher K.]

The Crab Pulsar's magnetic field is slowing its spin. By the year 4000, it will have slowed from 33rpm to 17rpm. Also, it will be visible in amateur telescopes.

M1 made it onto the list of Bob Berman's fifty strangest objects--in fact, it's in the top ten!

More information:
50 Weirdest Objects in the Cosmos, p. 88.

[Christopher K.]

I attempted to get this elusive nebula from HRPO a few hours ago. I'm almost positive I had the right star field--Zeta Tauri makes it easy to be in the right neighborhood. However, when I looked when I thought M1 should be I saw a couple of very faint stars...so I have a little doubt as to whether I had the right FOV.

[Christopher K.]

The Crab Nebula is first in Messier's famous catalog. On Saturday the 10th at 10am, the Science Academy session will be "Names and Catalogs". Cadets will learn the lists that are keys to the Heavens! The session is for eight- to twelve-year-olds; parents may stay with or leave their kids.

More information:
http://hrpo.lsu.edu/programs/academy.html

[Christopher K.]

It is oh-so-subtle...from a distance. In almost 1000 years this remnant of a supernova explosion has expand to ten light-years across. Now a time-lapse, literally just a few seconds long, give a visual to that expansion.

19 January 2020 APOD: https://apod.nasa.gov/apod/ap200119.html

[Christopher K.]

A large amount of work over a long amount of time--that was Detlef Hartmann's commitment to bring to the public a time-lapse of the Crab Nebula's expansion. One may want to use a computer function to slow down the two-second video.

20 March 2023 APOD:
https://apod.nasa.gov/apod/ap230320.html