NGC4945, the second brightest galaxy in Group A of the Centaurus A/M83 Galaxy Group, after Centaurus A. Approximately 11.7Mly away from Earth (redshift = 583kms, z=0.0019433), the galaxy shines at a magnitude of 9.3. The apparent diameter of the galaxy upon the sky is 20arcmins, equating to a lineal diameter of 68077.8ly, around 1/3 the size of the Milky Way. X-ray observations of the galaxy show it to be an usually energetic Seyfert Type 2 galaxy that harbours a supermassive black hole of around 1.4million solar masses. It's Hubble classification is SB(s)cd.

The galaxy directly above ngc4945 is ngc4976, an E4pec elliptical galaxy which lies at a distance of approx' 41Mly (redshift = 1453kms, z = 0.00484). It's apparent diameter on the sky of 5.6armins gives a lineal diameter of 66787.9ly, slightly smaller than ngc4945. It shines with an apparent magnitude of 11.

The two "high beam" stars in the pic are Xi1 and Xi2 Centauri. Xi1 Cen (below ngc4945) is a class A0V star with a mass 2.39 times solar, a radius of 2.7 solar and a luminosity of 43.2 solar. Surface temperature is 10462K. The star is 125Ma in age and has a rotational velocity of 185kms. Shining at 4.83mag, it's parallax of 14.79mas gives a distance of 221ly.

Xi2 Cen (star upper right) is a triple star system, consisting of a spectroscopic binary, component A, orbited by a distance single star, component B. Component A consists of two B class stars, the brightest of which is either a B1.5V or B2IV star, depending on the source. The two stars orbit one another with a period of 7.4697 days. The primary, which weighs in at 8.1 solar masses, shines with a luminosity of 1702 solar, at a surface temp of 20790K. Rotational velocity is 25kms. Given the star's characteristic, stellar models put its age at 11.5Ma. Component B is an F7V star which is separated from the main pair by 25.1 arcsec, orbits them with a period of 41000 year. The star is 1.25 solar masses and shines with the luminosity of 2.4 solar from a surface temp of 6194K. The primary A shines at an apparent magnitude of 4.3, whilst B shines at 9.38. The system moves with a peculiar motion (compared to the Sun) of around 16.2kms, is a member of the Scorpius-Centaurus OB Association and lies at a distance of 470ly.

Pic was taken with t68 at Bathurst Observatory (BAT-iTelescope Network). 13x120sec subs