RCW 111

RCW 110 and RCW 111 appear to be bright spots in the same object, Gum 54.

Avedisova places both RCW 110 and RCW 111 in star formation region SFR 340.79-1.01 along with two masers, the star cluster Lynga 14 and the HII region IRAS 16506-4512.

Dutra and colleagues say that the infrared cluster [DBS2003] 106 is deeply embedded in RCW 111 at a distance of 2600 parsecs.

The Wolf-Rayet star WR 79b=HD 152386 is located in a similar direction as Gum 54 but has a distance estimate of 2900 parsecs and so may be a background object. On the other hand, a 1999 paper by Benaglia and Cappa says that HD 152386 is definitely associated with Gum 54, but give a quite different O6 Ia f class for this star. They give a photometric distance of 2500 parsecs for the star and suggest a distance of 2800 for an atomic hydrogen (HI) bubble that appears to surround the region.

RCW 110 and RCW 111 appear as one object in this MSX infrared image.

RCW 112

This is the planetary nebula NGC 6153. You can find interesting false colour multiwavelength images of NGC 6153 here (see Figure 3).

RCW 113

RCW 113, also called Gum 55, is a huge region of diffuse nebulosity surrounding the Sco OB1 association and its core ionising cluster, NGC 6231.

Gum notes that this region is "A large roughly semicircular loop, whose ragged appearance is due in part to overlying obscuration. At its centre is the galactic cluster NGC 6231, which is the nucleus of an O-Association".

Humphreys lists 3 O-stars and 27 ionising B-class stars in Sco OB1 and gives a distance of 1910 parsecs.

Kharchenko lists 15 ionising stars for NGC 6231 including 9 O-stars, 5 B-stars and the Wolf-Rayet binary star WR 79. The hottest O-star listed by Kharchenko is the O6 III:(f)p binary giant HD 152233. She gives an age of 6.4 million years and a distance of 1250 parsecs for the cluster. A 2008 study gives a distance of 1640 parsecs and finds 15 O-stars in the direction of the cluster core.

You can find a better view of the bat-like edge of this nebula here and a stunning view of the full RCW 113 nebula and the larger Sco OB1 region here.

You can see the full extent of the vast nebular clouds in the Sco OB1 region in this SuperCOSMOS explorer image and some photographs of SFO 82, the prominent bright-rimmed cometary globule visible inside RCW 113, here. SFO 82 is often called "the Dark Tower of Scorpius" by amateur astronomers and is described in detail in this 1976 paper.

RCW 114

This huge but very faint nebula is probably a ring nebula surrounding the Wolf-Rayet star WR 90, expanding into a pre-existing cavity created by the supernova remnant SNR 343.0-06.0.

RCW 115

According to the RCW catalog, this is a 4x2 arcminute medium-bright nebula. However, there is no nebulosity in this direction in the SuperCOSMOS hydrogen-alpha images and SIMBAD lists no references in the scientific literature beyond the RCW catalog itself. It appears that this nebula may not exist.

RCW 116

This is IC 4628, the Prawn nebula, which is a dense concentration of gas and dust ionised by the star cluster Trumpler 24. It lies within the more diffuse nebula RCW 113 surrounding the Sco OB1 association.

Avedisova says that the Prawn nebula is ionised by two O-class giants: HD 332417 (O6 III) and HD 152723 (O6.5 III) at a distance of 2100 +/- 200 parsecs. She places it in star formation region SFR 344.22+1.70 with 59 components, including 19 infrared sources, 8 masers, the emission star MCW 1264 and Trumpler 24. (Avedisova misspells the name of the emission star as MWC 1264, but this is clearly an error. The HD catalog gives a completely different location and spectral class for HD 332417 so it appears that Avedisova is mistaken in this case.)

Reed lists the O5 III giant LS 3873=HD 322417, the O6 III giant LS 3868, the O8 star LS 3843, the O9 star LS 3840 and the O9.5 IV subgiant LS 3874 in this direction as well. Given the similarity in names, it seems possible that Avedisova's HD 332417 reference was meant to be HD 322417.

The nebula contains the infrared clusters [DBS2003] 113 and [DBS2003] 114, as well as the infrared group [DBS2003] 117.

This is a black and white hydrogen-alpha image of the Prawn nebula - much more colourful images are widely available on the Internet. You can also see several knots of young star development in this MSX infrared image.

Given the high concentration of O-stars in this direction and the prominence of the Prawn nebula at infrared and radio frequencies, it is surprising that this region has received so little study to date in the scientific literature.

RCW 117

Avedisova lists two ionising B-class stars: the HD 155051 (B1 Ib) and HD 155134 and places the nebula in star formation region SFR 345.41-0.98 with 5 masers and the infrared HII region IRAS 17059-4132.

RCW 117 contains the deeply embedded infrared cluster [DBS2003] 116 at a distance of 2800 parsecs according to Dutra and colleagues.

RCW 117 is a very bright radio and infrared source and can be seen in this Spitzer space telescope image.

RCW 118

RCW 118 is a ring nebula surrounding the Wolf-Rayet star WR 85 at a distance of 2800 +/- 700 parsecs. The nebula is embedded in a 1900 solar mass atomic hydrogen (HI) bubble.

You can see the full extent of the nebula in this SuperCOSMOS hydrogen-alpha image.

RCW 119

This HII region is a wind blown bubble surrounding the O6.5 Ia supergiant and prominent X-ray eclipsing binary HD 153919. It is in the same direction (but much further away) as the star cluster NGC 6281.

HD 153919 is a runaway star ejected from the Sco OB1 star association in a supernova explosion about 2 million years ago.

You can see the full extent of this huge nebula in this hydrogen-alpha SuperCOSMOS image.

According to SIMBAD, this object is more precisely Gum 57B. Avedisova lists a second ionising star for RCW 119 (the O9 II-III class HD 153426) but SIMBAD says that this is associated with the separate HII region Gum 57A. A 2004 paper concludes that HD 153426 is part of an uncatalogued star cluster at distance of 2100 parsecs.

RCW 120

According to Avedisova, RCW 120 is ionised by the O8 V star CD -38 11636 and the B2 V star VDBH 84B. She places the nebula in the star formation region SFR 348.26+0.47 along with 3 masers and the radio HII region [CH87] 347.386+0.266.

A 2005 study refers to the Avedisova paper and gives the class of the main ionising star as O6 V, so CD -38 11636 may be hotter than Avedisova suggests.

You can view an interesting multiwavelength image of RCW 120 and see the Spitzer infrared view here.