Archive for the ‘M1’ Category

M1: Crab Pulsar Discovery

August 22, 2007

Steinn Sigurdson reports that the Crab Pulsar, and consequently other pulsars, have been discovered months earlier than previously known, in summer 1967, by US Air Force officer Charles Schisler on duty.

Charles was on radar duty at Clear USAFB Alaska in summer 1967, when he noticed and logged a fluctuating radio source which was not moving, i.e. at fixed RA and Dec. The next day it was there again, and when he determined its position, he identified it with the Crab Nebula. Subsequently, he found a number of further pulsars.

USAF decided that this was not their business, and didn’t publish his findings. Therefore, Joycelyn Bell independently found her first pulsar a couple of months later.

Full story:

SEDS M1 page:


M1: Chandra image of the Crab Nebula

October 25, 2006

[Chandra image of M1]

Chandra image of M1

Chandra X-ray Observatory has obtained a new image of the Crab Nebula – just in time for Halloween ..

This is a multi-spectral image was composed from X-ray (Chandra), optical (Hubble) and infrared (Spitzer) individual images.

Chandra Press Release (October 24, 2006):

Also available: Spitzer Press Release (October 25, 2006):

Related Hubble Press Release (December 1, 2005):