Gum 41

According to Avedisova, RCW 61 is ionised by three O9 giant stars: HD 100099 (O9 III), CD -62 535 (O9 II) and HD 100444 (O9 II), as well as three B-class stars, at a distance of 2950 +/- 400 parsecs. (SIMBAD reports that CD -62 535 and HD 100444 are the same star.) She places RCW 60, RCW 61, RCW 62, Gum 39, Gum 40, Gum 41, Gum 42, and IC 2944 in star formation region SFR 293.64-1.41 with 51 components, including 7 masers and 18 infrared sources. Humphreys says that the hot stars in this direction form the Cru OB1 association at an average distance of 2510 parsecs.

The creator of this striking colour image calls this nebula complex the Running Chicken nebula.

Gum 42

This is IC 2944 (Gum 42), sometimes called the Lambda Centaurus nebula. According to Avedisova, RCW 62 is ionised by the O6 III giant HD 101190, the O6 V star HD 101436 and the O9 IV subgiant HD 101223 as well as the B0.5 Iab supergiant HD 101545 at a distance of 2400 +/- 250 parsecs. (SIMBAD gives a much cooler B6Ib/II class for HD 101436.) She places RCW 60, RCW 61, RCW 62, Gum 39, Gum 40, Gum 41, Gum 42, and IC 2944 in star formation region SFR 293.64-1.41 with 51 components, including 7 masers and 18 infrared sources. Humphreys says that the hot stars in this direction form the Cru OB1 association at an average distance of 2510 parsecs.

Dutra and colleagues say that RCW 62 contains the infrared group [DBS2003] 69, although curiously they give a distance of only 1700 parsecs.

The creator of this striking colour image calls this nebula complex the Running Chicken nebula. You can also see the spectacular MSX 8μm infrared view here.

Lambda Centaurus is the bright star in the upper right of the image - it is a foreground star at a distance of only 63 pc.

Gum 43

The infrared cluster [DBS2003] 77 is embedded in RCW 65, for which Dutra and colleagues give a distance of 5100 parsecs.

Avedisova places RCW 65 in star formation region SFR 300.90+1.23 with three masers, the infrared HII region [WHR97] 12320-6122 and the star cluster Ruprecht 105.

RCW 66 and RCW 67 appear to have a similar distance and direction as RCW 65.

Gum 44

Avedisova places RCW 66, RCW 67, and Gum 44 together in the star formation region SFR 301.05+0.89 along with the infrared HII region [GSL2002] 30 and the two optical nebula Bran 391A and Bran 391B. (SIMBAD identifies RCW 66 and Bran 391B.) Dutra says that RCW 66 includes the infrared cluster [DBS2003] 78 at a distance of 5000 parsecs.

RCW 66 and RCW 67 appear to have a similar distance and direction as RCW 65.

Gum 45

Although once believed to be an HII region, RCW 69 is now established to be the bipolar planetary nebula PN G302.1+00.3 at a distance of 1300 +/- 200 parsecs.

Gum 46

RCW 71 is ionised by the O9.5V star CP -60 4312 at 2200 +/- 300 parsecs according to Avedisova and contains the infrared cluster [DBS2003] 80 at 2800 parsecs according to Dutra.

A 2005 study notes that the nebula is surrounded by an emission ring, which can be seen in this MSX infrared image.

Gum 47

This is the planetary nebula NGC 5189 = Gum 47 = IC 4274.

Gum 48a

This HII region surrounds and is ionised by the young cluster Stock 16, which is part of the Cen OB1 association and contains the reflection nebula complex VdBH 60a, VdBH 60b, VdBH 60c and VdBH 60d. The region is probably physically connected to the huge and diffuse m Cen nebula.

Kharchenko lists 9 ionising members of Stock 16, including the O stars HD 115455 (O8) and DM -61 3587 (O 9.5 V) as well as 7 B-class stars. She gives a distance of 1640 parsecs and an age of 6 million years.

Dutra places the infrared star group [DBS2003] 86 in VdBH 60b at 2400 parsecs and the infrared star group [DBS2003]85 in VdBH 60d at 2100 parsecs.

Avedisova places this nebula in star formation region SFR 306.20+0.18, along with the emission star IRAS 13168-6208 and the dark cloud Dcld 306.2+0.1.

Although the little documented m Cen HII region is named after the prominent G6 II giant m Cen near its core, it is of course ionised by several much hotter OB stars. Avedisova calls this huge diffuse nebula Ge 136 and lists HD 116796 (O9 V) as the main ionising star, along with two B2 class stars. SIMBAD gives an O9 II class for HD 116796 but curiously appears to be missing the surrounding nebula all together.

You can view a larger image of RCW 75 here and the full extent of the nebulosity (including the huge diffuse m Cen nebula) in this SuperCOSMOS hydrogen-alpha image. You can also see RCW 75 at the edge of the far larger (and twice as distant) RCW 74 nebular complex in this Spitzer infrared image.

Gum 48b

This is a ring nebula around the Wolf-Rayet star WR 55.

Gum 48c

This 1.7 million year old nebula forms a ring around a central ionising star. A 2002 paper gives a distance of 5300 +/- 400 parsecs and identifies the ionising star, which is visible in both hydrogen-alpha and infrared, as either a late O-class star or Wolf-Rayet star but does not cite a catalog identifier.

A magnificent infrared image of this nebula can be found here and a different version (with more infrared frequencies visible) can be found on this Spitzer image.

Gum 48d

Gum 48d (RCW 80) is an HII region ionised by the B0 IP supergiant HR 5171B, which has as a companion the highly variable G8 Ia supergiant HR 5171A. It is located in the Centaurus arm at a distance of about 3500 parsecs.

Avedisova also lists the B2 Ia supergiant HD 119646 as an ionising star and gives an identical distance estimate of 3500 +/- 800 parsecs.

SIMBAD follows several sources in identifying RCW 80 with the supernova remnant SNR 309.2-00.6. However, the nebula and the radio peak within the supernova remnant seem to have different locations as can be seen in this Parkes radio image. A 2009 paper states clearly that the HII region and the supernova remnant are two distinct and likely unrelated objects.

RCW 80 can be seen in this Spitzer infrared image.

Gum 49

According to a 2006 paper, the Coffee Bean nebula is 310 thousand years old and is ionised by the O9.5 IV subgiant LSS 3423 = CPD-54 6791 at a distance of 2800 parsecs. A follow-up 2007 paper identified two dense cores in the small molecular cloud associated with RCW 98, one of which contains 3 young stellar objects. Avedisova gives a similar distance estimate of 3000 +/- 400 parsecs for both RCW 97 and RCW 98.

Gum 50

Avedisova lists 5 ionising stars, including the hot O5 III giant LSS 3443, the O9.5 II giant CP -53 6950 and 3 B-class supergiants at a distance of 3540 +/- 460 parsecs. She places the nebula in star formation region SFR 328.60-0.51 along with the star cluster Trumpler 23.

The Georgelins give an O7 III class for LSS 3443 and SIMBAD lists it as a B-class star. A 2006 paper gives an age of 700 milion years and a distance of 2200 parsecs for Trumpler 23, raising some doubts as to whether this cluster can really be associated with RCW 99.

According to a 1975 paper, RCW 99 is an extended HII region with low density and 102 solar masses of gas and dust.

Dutra says that the infrared cluster [DBS2003] 98 is deeply embedded in RCW 99 at a distance of 3500 parsecs.

RCW 99 is an intensely bright infrared source as can be seen in this Spitzer image.