Archive for October, 2006

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):


M109: The identity of M109

October 24, 2006

Henk Bril has recently found possible evidence that Pierre Méchain, when discovering this “nebula near Gamma UMa,” may have actually observed NGC 3953, not NGC 3992 which is usually identified with M109. He found this when investigating Fortin’s revision of Flamsteed’s Atlas Celeste of 1795, as revised by French astronomers Lalande and Méchain.

See Henk’s story at

Henk’s notion can be augmented by the manuscript note of Charles Messier on this object, apparently a semi-literal write-down of Méchain’s discovery note to him:

“Nebula near Gamma UMa, same right ascension a bit near this star and 1 deg .. more south. Discovered by M. Méchain on March 12, 1781.”


More on M109 (NGC 3992):
More on NGC 3953:

As of this time, we are certainly aware that several scenarios are possible: Méchain may have discovered NGC 3953 on March 12, 1781, and on March 24, 1781, Messier saw either this one also, or – in that case discover – NGC 3992. Messier’s mentioning of this object within the published description of M97 indicates that at least he had really seen some object here.

M31/M32: Another Spitzer image of the Andromeda Galaxy and its companion

October 24, 2006

[Spitzer image of M31/M32]

Spitzer image of M31/M32
Investigating Spitzer images of M31, astronomers found evidence for a heavy collision of the Andromeda Galaxy M31 with its small elliptical companion M32, about 210 million years ago.

Spitzer Press Release:

M87: Chandra Reviews M87 Center

October 9, 2006

[M87 Nucleus by Chandra]

M87 Nucleus by Chandra

Chandra X-ray Observatory has imaged the nucleus of giant Virgo Cluster elliptical galaxy M87

M31: Spitzer images the Andromeda Galaxy

October 9, 2006

[M31 by Spitzer and Galex]

M31 by Spitzer

This image is a false color composite comprised of data from Galaxy Evolution Explorer’s far-ultraviolet detector (blue), near-ultraviolet detector (green), and Spitzer’s multiband imaging photometer at 24 microns (red).

[M31 by Spitzer]

M31 by Spitzer – gas and dust

Another semi-recent Spitzer image of M31 (June 5, 2006)