Halos around planetary nebulae

Discovered 1900 visually by Barnard (first photograph 1935 by Duncan) halos represent the most faintest but the most massive part of nearly all planetary nebulae.

The faint envelopes are a result of a late evolutionary stage of a dying star between 0,6 to 10 solar masses. During this stage (late AGB) the star lost up to 70% of his mass because of thermal pulses short before the much brighter planetary nebulae began to shine

 

designation

telescope (aperture), magnification, limiting magnitude, description, [sketch]

Messier 27

[OIII], Steve Richards

recombination halo

14", 100x, [OIII], fst 7m0+
under very good transparency NW arc easy noticeable, direct vision detail

16", 129x, [OIII], fst 7m0+
arc to the NW easier; sure and steadily detection with averted vision, starts on a 13mag double star and run 4' to the SW; E arc more difficult and only popping in and out of view with averted vision, shorter, starts on a 9mag star and runs to the N

27", 172x, [OIII], fst 6m5+
NW arc direct visible as a 4' long glow; E arc more difficult and despite the aperture hard to see without the exact knowledge of the position, longish glow just N of a 9mag star, seems to be larger than on photos
sketch

 

Messier 57

[OIII], Vicent Peris (OAUV/CAHA/PTeam)
 

first halo = recombination halo

16", 106x-180x, UHC, fst 7m0+
difficult confirmation on the long NW side because of a 14mag star chain at the diameter of the halo; best filter for 16" UHC; from 106x faint irregularities along the outer SE side suspected but to small to confirm, with 180x and exactly at the S tip a 0,5' long glow can be seen, confusion with a 15mag star excluded; another fainter section suspected, starting from the 9mag star at the E side and runs 0,5' to the SW; complete ring around the PN not visible
sketch

27", 244x, UHC, fst 7m0+
the inner circle of the halo can be detected with 3mm EP and UHC filter; closed ring with 2,5' diameter (2x-2,5x diameter of the core); shape of the halo similar to the elongated core; brightest part to the SW side

48", 203x-488x, NPB, fst 7m0+
with 203x and NPB bright and direct vision glow around the bright core; 3:2 elongated with 2,5'x2' diameter; with 488x brighter fringes/ejections which sits directly on the bright rim of the core are directly visible
 

Messier 97

[OIII], Corradi et al. (2003)

recombination halo

27", 113x, [OIII], fst 7m0+
very difficult and faint; halo visible around a half ring from SE over NE till NW; brightest segment to the NE, just S of the 12mag foreground star; another brighter laminar knot to the starting point at the SE; the whole SW side not visible
 

NGC 40

Hα, Balick et al. (1992)

27", 172x-293x, fst 7m0+

even under superb conditions nothing visible or suspected with all filter combinations
 
NGC 1514

Hα/[OIII]/RGB, Don Goldman

recombination halo?

27", 172x, [OIII], fst 7m0+
halo visible as a very faint glow around the NE, NW and SW side of the bright core; nothing visible at the SE side; only around 0,5' thick and attached to the core
sketch

 

NGC 2020

[OIII], Corradi et al. (2003)

27", 172x-293x, [OIII], fst 7m0+
difficult and very faint halo; three brightness levels; first the inner core with a bright rim and a knot to the SW; second the also bright shell with 2x diameter of the inner core; and third the very faint outer AGB halo; the halo is not steadily visible with averted vision and only popping in and out of view, a brighter knot at the SW rim (similar to the knot at the rim of the inner core) is also popping in and out; both details - halo and knot not visible at the same time; both details also visible with 172x and 293x
sketch

 
NGC 2438

[OIII], Corradi et al. (2003)

first halo = recombination halo

27", 113x-172x, [OIII], fst 7m0+

even under superb conditions nothing visible or suspected with all filter combinations
 
NGC 2867

[OIII], Corradi et al. (2003)

28", 313x, [OIII], fst 7m5+
under best transparency halo even visible without filter; with [OIII] bright and direct vision, round, no bright rim
sketch
NGC 3242

Hα, Corradi et al. (2003)

20", 114x-194x, [OIII] fst 7m0+
- inner halo: very faint but clearly visible with averted vision + [OIII] filter and 114x; 3x-4x diameter of the bright inner core + shell (~3' diameter); knot to the S popping in and out of view with 194x
- outer halo: brightest part suspected even without filter W of the PN core; with [OIII] and 114x (4,4mm EP) easy to hold with averted vision, brightest part around 9' SW of the PN core with brighter rim to the E edge, fainter and narrower outgoing to the S; UHC with worsen reaction
sketch
NGC 3918

[OIII], Corradi et al. (2003)

28", 195x-391x, [OIII], fst 7m5+
bright (inner) halo around very bright core; good reaction with [OIII]; halo reaches just above a double star NW, around 1' diameter; jet to the SE within the inner halo

 
NGC 5882

[OIII], Johannes Schedler (Chart32)

28", 260x, [OIII], fst 7m5+
PN core surrounded and attached by an direct visible 1:2 shell; brightest filamentary halo fragment 1' E of the core, steadily visible with averted vision as an 1:2 E-W glow, visible from 184x-447x, best magnification 260x + [OIII] filter ; two other smaller fragments 2' SW, each visible with averted vision for seconds as laminar glows
sketch

 
NGC 6309

[OIII] (blue), Rubio et al. (2015)

27", 293x, [OIII], fst 6m5+
nothing visible without filter and UHC filter; [OIII] brings out a very faint round glow around very bright core; within the round glow two slightly shifted brightenings are visible, the NE one seems to be larger and longer with a not so difficult visible peak at the NE end, the SW seems to be a little bit shorter with a better defined but very unremarkable limb brightening
sketch

 
NGC 6369

[OIII], Corradi et al. (2003)

16", 360x, no filter, fst 6m5+
with higher magnification a faint glow directly W of the ring is suspected
sketch

27", 293x, [OIII], fst 6m5+
even without filter and 172x two faint extensions to the E and W suspected; brighter impression with UHC or [OIII]; best view with 293x + [OIII]; two short but bright "ears" directly connected to the bright inner ring; W glow smaller but brighter; E glow larger from E to NE but fainter, a brighter knot is visible at the middle of the halo; nothing visible to the N and S
sketch

 

NGC 6543

[OIII], Ricky CN

16", 51x-129x, [OIII], fst 6m5+
IC 4677 direct vision and easy visible as a 1:2 elongated knot; no other structure visible

27", 172x, [OIII] fst 6m5+
IC 4677 bright and direct vision with three peaks within the large 1:2 knot, inner halo visible as a very faint round glow, no outer halo and no filamentary structures seen

48", 203x, NPB, fst 7m0+
IC 4677 with four knots, two brighter ones in the E in a row, at the NW end third (second brightest) and the faintest at the SW end; around very bright core the inner halo is visible with direct vision as a N-S elongated glow with 1.5'x1' size; outer halo visible with averted vision, the rim degrades in four knots, brightest knot to the ESE above a 14mag star, the two second brightest knots to the S and NE and the faintest knot to the W 1' under IC 4677, no inner structure visible
 

NGC 6578

[OIII], Corradi et al. (2003)

27", 293x-419x, [OIII]/UHC, fst 7m0+
beside the very bright core (~7") and the fainter shell (~13") the halo is also suspected with 419x and UHC or/and [OIII], no sure observation; whole system very small, and deep in the sky, so it needs to much magnification?
sketch (with shell only)
 
NGC 6629

[OIII], Corradi et al. (2003)

27", 293x, [OIII], fst 7m0+
good defined and bright core of around 16"; around core very faint glow with around 3x diameter of the core, glow reaches from the rim of the core to half the way to a 15mag star; N side better defined; glow suspected even without filter, with [OIII] sure confirmation
sketch
 
NGC 6751

[OIII], Corradi et al. (2003)

27", 293x, [OIII]/UHC, fst 7m0+
halo only suspected to the S and to the W; no sure detection, negative observation
 
NGC 6772

H2, Fang et al. (2018)

27", 113x-172x, [OIII], fst 7m0+
halo clearly visible as a very faint glow around the core from SE over E to N, brightest part to the E, N part very difficult and only suspected, no halo structure to the W; sure observation
sketch
 
NGC 6803

Hα/[NII], Balick et al. (1992)

27", 293x-419x, [OIII], fst 6m5+
halo only suspected; very faint glow visible at 419x, but unsure if halo or overexposure of the very bright PN core
 
NGC 6826

[OIII], Corradi et al. (2003)

27", 172x, [OIII], fst 6m5+
halo already suspected without any filter; with [OIII] from 172x to 293x bright and direct vision detail around the core, rim to the SW and NE better defined, knot within the rim to the NE, filling complete within the round glow but somewhat brighter toward the SW side
sketch
 
NGC 6852

Hα/[OIII]/RGB, Johannes Schedler (Chart32)

27", 293x, [OIII], fst 6m5+
halo visible as a very faint extension from the core to the NW; difficult but sure observation; other extensions not visible
sketch
 
NGC 6884

Hα, Corradi et al. (2003)

27", 172x, [OIII], fst 6m5+
halo visible as a very faint, round glow with 4mm EP and [OIII] only; not visible with higher magnifications; around 1,2' diameter; somewhat brighter within the glow at the SW side; no rim brightening
sketch
 
NGC 6891

Hα, Guerrero et al. (2000)

27", 172x, [OIII], fst 7m0+
with low magnification core and shell merges as one inner and bright detail and are not separately visible; much fainter halo suspected with 113x and [OIII] and better visible with 172x; round with 3x-4x of the diameter of the shell (around 1,2'); S side (filling) a little bit better defined
sketch
 
NGC 6894

LRGB/Hα/[OIII], Bernhard Hubl

27", 293x, [OIII], fst 7m0+
bright core somewhat fringed to the SW but no second shell or round glow around the core; negative observation
 
NGC 7009

Hα, Corradi et al. (2003)

27", 172x, [OIII], fst 7m0+
even without any filter bright round glow around very briht green core; [OIII] filters brings our the halo even brighter, direct vision glow of around 4' diameter, brighter regions to the S and NE, appears somewhat scabby without showing individual spots
sketch
 
NGC 7027

Ralf Burkart

16", 180x, [OIII], fst 6m5+
halo noticeable around the very bright core
sketch

27", 293x, [OIII], fst 7m0+
glow around very bright core even visible without filter; good reaction with [OIII] filter; diameter of the halo reaches close up to a 14mag star in the E and is around 1,5'; bright, 1:2 elongated core seems to be shifted to the N within the halo, center seems to be at the S border of the core; brightest part of the halo sits directly SW-W on the bright core; a dark border suspected at the N end; with high magnification brighter halo shell around core visible
sketch (outer halo)
sketch (inner shell)
 

NGC 7048

LRGB/Hα/[OIII], Bernhard Hubl

27", 172x, UHC, fst 7m0+
under very good transparency N extension up to a 13mag star only suspected with UHC; very difficult and not steadily visible; [OIII] negative results; S and W halo sides not visible
 
NGC 7293

Hα/[NII], Corradi et al. (2003)

27", 113x-172x, UHC, fst 7m0+
even under perfect conditions (47N) of an high alpine location brightest halo arc only suspected; strong contrast effect of the bright rim of the core makes it nearly impossible to decide whether glow is the halo arc or only a contrast phenomenon; within a small triangle of 15mag stars 11' NE of the center a faint glow suspected; three observer also only suspected extremely faint glow and were not sure of a positive observation
 
NGC 7662

[OIII], Corradi et al. (2003)

14", 100x, [OIII], fst 7m0+
halo easy visible with averted vision as a round glow with good defined edges of around 2' diameter

27", 172x, [OIII], fst 6m5+
with [OIII] flashy glow of around 2'-2,5' diameter around the bright core; two stars at the NE within the halo; a stellar peak is visible in a very faint arc at the NW edge of the halo; SE part of the halo seems to be a little bit brighter; edge sharply defined
sketch
 

IC 418

WISE (IR), Ramos-Larios et al. (2012)

27", 172x, [OIII], fst 7m0+
halo already visible as a faint glow around the bright shell with searching eyepiece at 113x without filter and is still visible up to 293x; best view with [OIII] and 172x at 4mm EP; halo visible as a bright and round glow with 2' diameter; diffuse edges with concentration towards the PN; somewhat brighter to the NE side; steadily visible with averted vision
sketch

36", 165x, [OIII], fst 7m0+
similar appearance like the 27" view but somewhat brighter; halo is visible with [OIII] as direct vision glow around the bright shell

IC 1454 (Abell 81)

Hα/[NII], Balick et al. (1992)

27", 172x, [OIII], fst 7m0+
halo only suspected, no sure observation
 
IC 1747

Hα/[NII], Corradi et al. (2003)

27", 113x-172x, fst 7m0+
halo definitely not visible or suspected with all filter combinations
 
IC 2165

[OIII], Corradi et al. (2003)

27", 172x-293x, fst 7m0+
very faint but sure visible; round glow touches 15mag star 0,5' SE, so its diameter is around 1'; seems to be two-stage, an inner, somewhat brighter glow of around 0,5' diameter around the very small ring core and the mentioned 1' outer glow; W side of the glow somewhat better defined and visible
sketch
 
IC 2448

[OIII], Corradi et al. (2003)

28", 312x, [OIII], fst 7m5+
faint glow steadily visible with averted vision; round and diffse, no sharp edges
sketch
 
IC 4593

[OIII], Corradi et al. (2003)

27", 586x, fst 7m0+
halo fragment on the W side visible with high magnification and without filter, no difficult detection; faint extension to the S only suspected, no sure observation
sketch
 
IC 4997

V, Bond [HST]

27", 293x-837x, fst 6m5+
brighter halo even without filter around very bright inner core; overexposure?

27", 1172x, fst 7m0+
round glow 2 x PN diameter around double core up to high magnification; difficult to decide between halo or overexposure of the very bright core
sketch
 

Abell 30

[OIII]/Hα, Ian Smith

PN without shell and shell-like core

16", 51x, [OIII], fst 6m5+
faint PN, can hold it with averted vision, best with max. AP, not sharply defined
sketch

27", 172x, [OIII], fst 6m5+
with 4mm EP + [OIII] filter PN (halo) steadily visible with averted vision; sharply defined; around CS bright but very small ~15" diameter inner glow without any structure, only visible with filter
 

Abell 39

Hα/[OIII]/RGB, Don Goldman

PN without shell and shell-like core

4", 31x, [OIII], fst 6m0+
extreme PN with 4-inch, PN is popping in and out of view at the right position with 3,5mm EP and [OIII]; can not hold it with averted vision, but sure observation; no CS without filter; structureless round glow

4" Bino, 23x, [OIII], fst 6m5+
nothing visible without filter; with 4,3mm EP and [OIII] a round glow is steadily visible with averted vision; faint but visible without problems; with 55x view to dark, PN not visible any more

16", 129x, [OIII], fst 6m5+
large, round disc with [OIII]; can hold PN steadily with averted vision

20", 121x, [OIII], fst 6m0+
faint glow without filter and max. AP; with filter and 4mm EP round, bright disk; darker to its middle; CS visible without filter
sketch

27", 113x-172x, [OIII], fst 6m5+
faint glow with EP 6mm and 4mm even without filter; with [OIII] easy target; best view with 172x (AP 4mm); exactly round with good defined edges, edge visible as a thin frame around the direct vision glow of the PN, frame a little bit segmented, brightest segment in the E, following with a smaller segment in the NW and S; CS direct vision without filter, even visible trough the [OIII]; did not try the galaxy within the PN
 

Cannon 1-5

[OIII], Corradi et al. (2003)

28", 312x-843x, [OIII], fst 7m5+
faint but steadily visible halo with [OIII] and averted vision around very bright core; small, round, ~0,5' diameter halo with better defined N side
sketch