sjastro
20-03-2010, 12:15 PM
A very faint object that required a total of 10.5 hrs of exposure.
8.5 hrs L=R, 1 hr R, 1 hr G, 1 hr B BRC-250, ST-X10ME.
Color image showing lobes only.
http://users.westconnect.com.au/~sjastro/bran147c.html (http://users.westconnect.com.au/~sjastro/bran147c.html)
Highly stretched inverted image showing outer extensions.
http://users.westconnect.com.au/~sjastro/bran147g.jpg (http://users.westconnect.com.au/~sjastro/bran147g.jpg)
AAO report on the object.
"PHR 0825-4013 (RCW 24, BRAN 147 A/B).
This unusually large bipolar PN was noted serendipitously by DJF from Sky Survey R films in 1995, and later reported as a possible new PN (Frew 1997), before being independently found on the AAO/UKST Hα Survey by Parker in 1998. It has a moderately-high red surface brightness, and had been previously catalogued as an HII region by Rodgers, Campbell and Whiteoak (1960) where it was given the designation RCW 24, and by Brand, Blitz & Wouterloot (1986).
A red image is presented by Neckel & Vehrenberg (1990), where it was again assumed to be a H
II region. However, even in deep UKST R-band images it exhibits evidence of classic bipolar morphology, with two wedge-shaped emission knots rather symmetrically placed around an 18th-magnitude blue central star candidate. Perhaps the sheer angular size of the object and close proximity to the Vela SNR mitigated against its identification as a possible PN. The new, deep, AAO/UKST Hα image (fig.1) has now revealed the fainter outer extensions of this PN for the first time, whilst preliminary spectra taken on the SAAO 1.9m show intense [NII] lines at λλ6548, 6584, allowing classification as a type I PN. "
fig 1
http://users.westconnect.com.au/~sjastro/AAOimage.jpg (http://users.westconnect.com.au/~sjastro/AAOimage.jpg)
Regards
Steven
8.5 hrs L=R, 1 hr R, 1 hr G, 1 hr B BRC-250, ST-X10ME.
Color image showing lobes only.
http://users.westconnect.com.au/~sjastro/bran147c.html (http://users.westconnect.com.au/~sjastro/bran147c.html)
Highly stretched inverted image showing outer extensions.
http://users.westconnect.com.au/~sjastro/bran147g.jpg (http://users.westconnect.com.au/~sjastro/bran147g.jpg)
AAO report on the object.
"PHR 0825-4013 (RCW 24, BRAN 147 A/B).
This unusually large bipolar PN was noted serendipitously by DJF from Sky Survey R films in 1995, and later reported as a possible new PN (Frew 1997), before being independently found on the AAO/UKST Hα Survey by Parker in 1998. It has a moderately-high red surface brightness, and had been previously catalogued as an HII region by Rodgers, Campbell and Whiteoak (1960) where it was given the designation RCW 24, and by Brand, Blitz & Wouterloot (1986).
A red image is presented by Neckel & Vehrenberg (1990), where it was again assumed to be a H
II region. However, even in deep UKST R-band images it exhibits evidence of classic bipolar morphology, with two wedge-shaped emission knots rather symmetrically placed around an 18th-magnitude blue central star candidate. Perhaps the sheer angular size of the object and close proximity to the Vela SNR mitigated against its identification as a possible PN. The new, deep, AAO/UKST Hα image (fig.1) has now revealed the fainter outer extensions of this PN for the first time, whilst preliminary spectra taken on the SAAO 1.9m show intense [NII] lines at λλ6548, 6584, allowing classification as a type I PN. "
fig 1
http://users.westconnect.com.au/~sjastro/AAOimage.jpg (http://users.westconnect.com.au/~sjastro/AAOimage.jpg)
Regards
Steven