SH 174
Sh2-174, also named Valentine's Rose, is a faint planetary nebula in Cepheus. The object was first noticed by Stewart Sharpless, who discovered the red nebula consisting of ionized hydrogen and the blue nebula of the double ionized oxygen (OIII). The ionized hydrogen and the ionized oxygen did not have the same center. The ionized oxygen is shifted west and the white dwarf (a stellar core remnant composed mostly of electron-degenerate matter) was discovered in the middle of the blue nebula (in the picture it can be seen as a small blue dot). In 2008 an Australian doctoral student discovered from the velocity of the nebula its age, i.e. the time at which it began to expand, did not coincide with the age of the white dwarf. The white dwarf was much too cool and thus too old - about a hundred times older than the nebula. The most plausible explanation for this is that a single white dwarf is just passing through the gas cloud and ionizing the gas surrounding it, so the nebula could not be caused by the mass loss of the dying star. Not all astronomers share this view and consider Sh2-174 a Planetary Nebula, namely PK 120+18.1. Also the astronomical database Simbad lists this object as PN.
-abstract from Baerenstein Observatory (www.sternwarte-baerenstein.de/sh2-174-en.html)
Camera: Moravian G2 8300
Filters: 31mm unmounted Optolong
Optic: Televue 102 f/7
Mount: Ioptron CEM60 HP
Autoguider: camera Magzero 5m on SW 70/500, Phd guiding
Frames Ha 7nm: 36X600sec - RGB: 7X900sec each - OIII 6.5nm: 16x900sec Bin1
Processing: Pixinsight, Photoshop
Ha taken on August 13 and 17 from Caldarola (MC) , RGB + O3 taken on October, 5 from Saint Barthelemy (AO)
Pubblicazioni: Coelum gennaio 2020
SH 174
Sh2-174, also named Valentine's Rose, is a faint planetary nebula in Cepheus. The object was first noticed by Stewart Sharpless, who discovered the red nebula consisting of ionized hydrogen and the blue nebula of the double ionized oxygen (OIII). The ionized hydrogen and the ionized oxygen did not have the same center. The ionized oxygen is shifted west and the white dwarf (a stellar core remnant composed mostly of electron-degenerate matter) was discovered in the middle of the blue nebula (in the picture it can be seen as a small blue dot). In 2008 an Australian doctoral student discovered from the velocity of the nebula its age, i.e. the time at which it began to expand, did not coincide with the age of the white dwarf. The white dwarf was much too cool and thus too old - about a hundred times older than the nebula. The most plausible explanation for this is that a single white dwarf is just passing through the gas cloud and ionizing the gas surrounding it, so the nebula could not be caused by the mass loss of the dying star. Not all astronomers share this view and consider Sh2-174 a Planetary Nebula, namely PK 120+18.1. Also the astronomical database Simbad lists this object as PN.
-abstract from Baerenstein Observatory (www.sternwarte-baerenstein.de/sh2-174-en.html)
Camera: Moravian G2 8300
Filters: 31mm unmounted Optolong
Optic: Televue 102 f/7
Mount: Ioptron CEM60 HP
Autoguider: camera Magzero 5m on SW 70/500, Phd guiding
Frames Ha 7nm: 36X600sec - RGB: 7X900sec each - OIII 6.5nm: 16x900sec Bin1
Processing: Pixinsight, Photoshop
Ha taken on August 13 and 17 from Caldarola (MC) , RGB + O3 taken on October, 5 from Saint Barthelemy (AO)
Pubblicazioni: Coelum gennaio 2020