deepskytraveler
November 10th, 2017, 03:35 AM
Object of the Week November 5, 2017 – Pa 5
Pa 5, PN G076.3+14.1, DSH J1919.5+4445, WHI J1919+44
Type: Planetary Nebula
Constellation: Cygnus
RA: 19h 19m 30.5s
DEC: +44° 45’ 44”
Magnitude: 15.7v
Size: 157” x 154”
J19195+4445, KIC 8619526
Type: Central Star
Type: PG1159
Magnitude (central star): 15.84
The planetary nebula Patchick 5 (PA 5) was discovered in 2005 by Dana Patchick, a member of the Deep Sky Hunters (DSH). The DSH group searches for previously unidentified objects in the archives of the Digital Sky Survey. To date the group has over 50 discoveries confirmed.
PA 5 has been classified as a probable bipolar planetary nebula. In direct images (DSS) it looks like a bipolar, but only the northeast lobe is apparent and the opposite lobe is much fainter. Its morphology is dominated by a dense equatorial toroid and faint polar extensions. The O-III and Hα images show a bright bar that looks like an equatorial structure with a faint lobe extending perpendicular to it toward the northeast. A much fainter extension is barely appreciated on the opposite side.
2799
Images of PA 5 obtained at the OAN-SPM 84 cm telescope
2802
2800
Images by Bernard Hubl, 2017
I was unable to locate any visual observations of PA 5; so, with the Cygnus well placed in the northern skies during this time of the year it presents a perfect opportunity for Deep Sky Forum members to give it a go. I anticipate this will be a challenging object.
The central star of PA 5 is itself an interesting object. The discovery paper by D. Patchick also presented a spectrum of the central star and remarked on this star being a very hot PG1159 star. A PG 1159 star, often also called a pre-degenerate, is a star with a hydrogen-deficient atmosphere that is in transition between being the central star of a planetary nebula and being a hot white dwarf. This is a rare O(He) spectral type. However, the story becomes even more interesting. From the spectrum, it was also discovered that the central star has a periodic variability consistent with a companion.
There happen to be six planetary nebulae known in the Kepler space telescope field of view. One of those is PA 5 and its central star Kepler Input Catalog (KIC) 8619526. Kepler’s light curve of the central star of Pa 5 gives a consistent period of 1.12 days with an amplitude of 0.5 mmag. It further shows extremely minimal orbital radial velocity shift. If the companion is a binary star it is being seen close to pole on. But even if that is the case the small amplitude of the curve implies the likely existence of a planetary companion.
Give it a go and let us know!
Pa 5, PN G076.3+14.1, DSH J1919.5+4445, WHI J1919+44
Type: Planetary Nebula
Constellation: Cygnus
RA: 19h 19m 30.5s
DEC: +44° 45’ 44”
Magnitude: 15.7v
Size: 157” x 154”
J19195+4445, KIC 8619526
Type: Central Star
Type: PG1159
Magnitude (central star): 15.84
The planetary nebula Patchick 5 (PA 5) was discovered in 2005 by Dana Patchick, a member of the Deep Sky Hunters (DSH). The DSH group searches for previously unidentified objects in the archives of the Digital Sky Survey. To date the group has over 50 discoveries confirmed.
PA 5 has been classified as a probable bipolar planetary nebula. In direct images (DSS) it looks like a bipolar, but only the northeast lobe is apparent and the opposite lobe is much fainter. Its morphology is dominated by a dense equatorial toroid and faint polar extensions. The O-III and Hα images show a bright bar that looks like an equatorial structure with a faint lobe extending perpendicular to it toward the northeast. A much fainter extension is barely appreciated on the opposite side.
2799
Images of PA 5 obtained at the OAN-SPM 84 cm telescope
2802
2800
Images by Bernard Hubl, 2017
I was unable to locate any visual observations of PA 5; so, with the Cygnus well placed in the northern skies during this time of the year it presents a perfect opportunity for Deep Sky Forum members to give it a go. I anticipate this will be a challenging object.
The central star of PA 5 is itself an interesting object. The discovery paper by D. Patchick also presented a spectrum of the central star and remarked on this star being a very hot PG1159 star. A PG 1159 star, often also called a pre-degenerate, is a star with a hydrogen-deficient atmosphere that is in transition between being the central star of a planetary nebula and being a hot white dwarf. This is a rare O(He) spectral type. However, the story becomes even more interesting. From the spectrum, it was also discovered that the central star has a periodic variability consistent with a companion.
There happen to be six planetary nebulae known in the Kepler space telescope field of view. One of those is PA 5 and its central star Kepler Input Catalog (KIC) 8619526. Kepler’s light curve of the central star of Pa 5 gives a consistent period of 1.12 days with an amplitude of 0.5 mmag. It further shows extremely minimal orbital radial velocity shift. If the companion is a binary star it is being seen close to pole on. But even if that is the case the small amplitude of the curve implies the likely existence of a planetary companion.
Give it a go and let us know!