RCW 145

RCW 145
Emission nebula
H II region
RCW 145
Observation data: J2000 epoch
Right ascension18h 02m 18s
Declination−23° 30′ 56″
Distance8480 ly   (2500  pc)
Apparent magnitude (V)16.8
Apparent dimensions (V)1.59° x 1.17°
ConstellationSagittarius
Physical characteristics
Radius47 ly
DesignationsNGC 6526, Sh 2-26, Sh 2-28, Gum 74
See also: Lists of nebulae

RCW 145 is an emission nebula in the constellation Sagittarius. RCW 145 contains both Sh 2-26 and Sh 2-28. It is ionized by the supergiant stars LS 4551 and LS 4538. It is possible it is associated with the Trifid nebula.

Visibility

RCW 145 is often imaged alongside nearby the nebulae of the Lagoon Nebula and Trifid Nebula. The nebula responds well to Hydrogen-alpha filters. It is also easily visible with a Sulfur II filter, however is not very visible in an Oxygen III filter. It is difficult to image with standard RGB.

Westerhout 28

Chandra X-ray Observatory image of Westerhout 28

In the direction of RCW 145 is also the supernova remnant SNR G006.4-00.1 (W28). W28 lies at a further distance of 1800 to 3300 parsecs. It contains multiple pockets of Maser activity. These pockets are 50-100 milliarcseconds in apparent size. W 28 is visible in most wavelengths, from radio waves to gamma rays. There is some ionization caused by W 28. It was initially thought to be cause by x-ray emissions; however, it has since been determined to be cause by cosmic ray emissions.

References

  1. ↑ "Sh2-28".
  2. ↑ "Sharpless (Sh2) - Astrobasics". 13 September 2022.
  3. ↑ Russeil, D. (2003). "Star-forming complexes and the spiral structure of our Galaxy". Astronomy and Astrophysics. 397: 133. Bibcode:2003A&A...397..133R. doi:10.1051/0004-6361:20021504.
  4. ↑ "Sharpless (Sh2) - Astrobasics". 13 September 2022.
  5. ↑ "Sh 2-26".
  6. ↑ "Sh 2-28".
  7. ↑ Giuliani, A.; et al. (2010). "AGILE detection of GeV γ-ray emission from the SNR W28". Astronomy and Astrophysics. 516. arXiv:1005.0784. Bibcode:2010A&A...516L..11G. doi:10.1051/0004-6361/201014256.
  8. ↑ "SH2-28 (Sharpless 28)".
  9. ↑ "Supernova Remnant W28 · NRAO/AUI Archives".
  10. ↑ Phan, V. H. M.; Gabici, S.; Morlino, G.; Terrier, R.; Vink, J.; Krause, J.; Menu, M. (2020). "Constraining the cosmic ray spectrum in the vicinity of the supernova remnant W28: From sub-GeV to multi-TeV energies". Astronomy & Astrophysics. 635: A40. arXiv:1910.09987. Bibcode:2020A&A...635A..40P. doi:10.1051/0004-6361/201936927.