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NEAT SOUTHERN PLANETARIES : 26a
Pb 5 in Vela


Pb 5 / He2-24 / Sa2-40 / Wray 16-39 / ESO 261-4 / PK 268+2.1 / PN G268.4+02.4 (09162-4529) is a small faint planetary in Vela discovered by M. Peimbert and G. Batiz in 1960 — some two years before K.G. Henize had rediscovered it in his mostly southern galactic plane Hα survey. The discoverers have only nine new Pb” PNe that are assigned to them. [See Appendix 1 : Tables 1 & 2 that listed all the catalogued or recognised faint Pb and Pc PNe,] Pb5 appears in Uranometria 2000.0 (Map 398) as PK 268+2.1 and does not feature in any of the other star maps except the Millennium Star Atlas.


Pb 5
Pb 5 Small

Fig. 4. PB 5 / He2-24 Wide Field. CDS Aladin Colour Image about AAO Red (red), J plates (blue), average (green) 11½′×11½′ in size.

Fig. 5. Closeup of Pb 5 / He2-24. CDS Aladin Colour Image Combined AAO Red (red), J plates (blue), average (green). Image about 30′×30′ shows the small planetary of 14.8v magnitude. Inspection, though not mentioned in the literature, shows one or even two stars superimposed over the nebulous object. Does this suggest the PNN is a double star or just appearing between us and the planetary?


Pb 5, placed in a moderately starry field, being found some 2.5°SE (PA 145°) from 2.1 mag. λ Vel / Lambda Velorum / Al Suhail (09080-4326), or alternatively, it lies 3.1°SSE (168°) from NGC 2792.

It is classed as V-V PNe Type I or 1 — stellar”, though against this it is only slightly less than 5 arcsec. At 14.8V, 14.2p, 16.0B, 13.3R magnitude, Pb 5 appears under high magnification and very dark skies in 20cm. as a faint and tiny smudge, that will be seen with care using averted vision. You will, however, positively need some finder chart or image to truly bag the object. Telescopes above 25cm. should have no problems seeing its tiny round disk. In 30cm., Pb 5 appears much like a tiny colourless, or perhaps slightly more greyish, round haze. An O-III filter is not probably very useful in this instance, except perhaps when using the largest of apertures.

I think it is more likely to be about 3 to 4 arcsec in diameter, smaller than the usually stated 5 arcsec. The PNN central star is 18.67V magnitude as is obviously well beyond amateur or even some professional telescopes! Overall radial velocity is +53.3 km.s-1 away from us. Very little is known about this planetary, and there seems no current estimate of distance or true size in the literature (2011).

Recommended for true deep-sky observers and certainly not one for the faint of heart! A field chart or using the wider image given here is highly recommended.

See Appendix 1, which Tabulates all known Pb and Pc PNe.


References to Pb 5


  1. Peimbert, M., Batiz, G., New Planetary Nebulae [Nuevas nebulosas planetarias.]”, Bol.Obs Tonatz.Tacuh., 2, Pt. 19, 19 (1960)
  2. Peimbert, M., Costero, R., New Planetary Nebulae II; [Nuevas Nebulosas Planetarias II]”, Bol.Obs Tonatz.Tacuh., 3, 33 (1961)
  3. Phillips, J.P., Marquez-Lugo, R.A. Mid- and Far-Infrared Photometry of Galactic Planetary Nebulae with the AKARI All-Sky Survey.”, Rev.Mex.Astron.Astrofis., 47, 83 (2011)

Appendix 1 : Catalogue of Pb and Pc Planetaries


All Diameters (arcsec) in the Table 1 & 2 are from the original paper, unless otherwise stated. Objects Pb 1-10 appear in Paper I. Objects Pc 11-24 appear in Paper II, but only four are accepted as new PNe in SIMBAD but as nine in Phillips & Marquez-Lugo (2011). The later ones are now instead labelled Pc xx. SSV (2008) is paper for distances derived by Stanghellini, L., Shaw, R.A., Villaver, E. (See References.)

Table 1: Catalogue of All Pb Planetaries (1960)

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No.  Other                 PN G      RA (2000)  Dec (2000)  Mag    Diam.   D.  Diam. N
     Designations                    hh mm ss.s  °   ′   ″         arcsec kpc. (pc.)  
--------------------------------------------------------------------------------------
Pb01 Sa 2-2  ARO 225     226.4-03.7  07 02 46.8 −13 42 34.7       18×13.2  ??   ??   1
Pb02 He2-08  Sa2-24      263.0-05.5  08 20 40.2 −46 22 58.8 13.3B   03    5.75 0.084 2
Pb03 He2-16  Sa2-33      269.7-03.6  08 54 18.3 −50 32 22.3 13.0B   07    3.4  0.115 3
Pb04 He2-22  Sa2-38      275.0-04.1  09 15 07.7 −54 52 43.8 11.2          2.81 0.153 4
Pb05 He2-24  Sa2-40      268.4+02.4  09 16 09.6 −42 28 42.8 14.8V   05     ??   ??   -


Pb06 He2-43  Sa-2-58     278.8+04.9  10 13 15.9 −50 18 59.2 17.6V   11    3.55 0.18  5
Pb07 He2-49  Sa2-61      283.8+02.2  10 31 33.4 −55 20 50.5         --     --   --   6
Pb08 He2-69  Sa2-77 My68 292.4+04.1  11 33 17.7 −57 06 14.0         05    5.15 0.125 7
Pb09 ARO 152 PK 046-03.1 046.3-03.1  19 27 44.8 +10 24 20.8 14.4B   07    3.57 0.121 8
Pb10 ARO 153 PK 048-02.1 048.0-02.3  19 28 14.4 +12 19 36.2         08    3.53 0.137 9
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Notes: (Recent Data from Simbad or Elsewhere)

1. Missing magnitudes are not visual but in J or K photometry
2. Dist.=9098pc. SSV (2008), increasing true diameter as the more acceptable 0.132pc.
3. Latest size 15×14″. Dist.=4893pc. SSV (2008), making the true Diameter as 0.165 pc.
4. Size 21.4×17.5″ Dist.=3680pc. SSV (2008), true Diameter is then 0.200 pc. PNN WC
5. Size 20.2×17.0″ Dist.=4419pc. SSV (2008), true Diameter is then 0.235pc.
6. Earlier catalogued My 60. Size 18.2×18.7″. Dist.=4803pc. SSV (2008) PNN WC
7. Earlier catalogued My 68. 5.0″. Dist.=7299pc. SSV (2008). PNN WC RV=+21.9km.s-1
8. Size 19.3×14.3″ Dist.=4706pc. SSV (2008)
9. Size 19.3×12.8″ Dist.=4830pc. SSV (2008)

Table 2: Catalogue of Pc Planetaries (1961)

--------------------------------------------------------------------------------------
No.  Other                 PN G      RA (2000)  Dec (2000)  Mag    Diam.   D.  Diam. N
     Designations                    hh mm ss.s  °   ′   ″         arcsec kpc. (pc.)  
--------------------------------------------------------------------------------------
Pc11 He2-172 ESO 179-11  331.1-05.7  16 37 42.7 −55 42 26.5 11.8B   7.0    ??   ??   1
Pc12 He2-180 Sa2-162     000.1+17.2  16 43 53.8 −18 57 12.0 13.7B 1.8×1.8  --   --   2
Pc13 Sa2-155 ESO 453-6   351.9+09.0  16 50 17.1 −30 19 55.5 12.9B    ??    ??   ??   3
Pc14 He2-195 Sa2-171     336.2-06.9  17 06 14.1 −52 30 00.4 16.5V   7.0   4.32  0.15 4
Pc17 He2-246 Sa2-216     343.5-07.8  17 35 41.7 −46 59 48.5 12.9B   5.0   6.12  0.15 5


Pc19 ARO 136 PK 032+07.2 032.1+07.0  18 24 44.5 +02 29 28.1 13.8B   2.8   6.75  0.09 6
Pc20 ARO 140 PK 031+01.1 031.7+01.7  18 43 03.5 −00 16 37.3          ??    ??   ??   -
Pc21 Sa2-364 ESO 591-16  013.8-07.9  18 45 35.2 −20 34 58.3 13.4     ??    ??   --   7
Pc22 ARO 160 PK 051-04.1 051.0-04.5  19 42 03.5 +13 50 37.3          ??    ??   ??   8
Pc24 He1-7   He2-463     066.9-05.2  20 19 38.1 +27 00 11.3 14.0B   5.0   5.78  0.14 9

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Notes: (Recent Data from Simbad or Elsewhere)

1. Data from Simbad but says this is of unknown object type
2. In SIMBAD, not Philips & Marquez-Lugo (2011). Dist.=14.35 kpc.!! SSV (2008) RV=-60.8km.s-1
3. Also StWr 4-3. Radial Velocity (RV)=-74km.s-1
4. ESO 227-5, 17.2B. Size=7.0×7.0″. Dist.=5796pc SSV (2008) True diam.=0.201pc. PNN WC
5. ESO 279-1 Size=5.0×5.0″. Dist.=8.18kpc. SSV (2008) True Dia.=0.200pc. RV=-142 km.s-1
6. RV=20.0km.s.-1 13.0R Size=2.8×2.8″. Dist. 10.39 kpc. SSW (2008)
7. RV=+42km.s-1 Object is oval not round.
8. Discovered by S.P. Apriamasvili in 1959
9. Mag. 12.0R, Size=12×10.7″. Dist.=7856pc SSV (2008) True Dia.=0.190pc. True Dia.=0.139pc.


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Last Update : 24th February 2012

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