Table 2:

Observational data for analyzed planetary nebulae.

Name	C	O++/O	He++/He	log			t	log S	log T
				[cm-3]	[ ]	[km s-1]	[year]	[erg cm-2 s-1 sr-1]	[K]	[]	[10 ]
H 1-16	2.50	0.880	0.097	3.77	2.0	20	2000r	-0.83	-	0.152	0.38
Hb 6	2.10	0.901	0.115	3.53	6.0	20	500s	-0.95	>4.48	0.2	1.20
M 2-10	1.32	0.625	-	3.10	4.2			-2.00	-	0.208	1.00
H 1-50	0.68	0.959	0.093	3.69	1.4	23	1300	-0.62	4.77	0.148	0.18
H 1-20	2.31	0.896	0.013	3.57	3.3	18	3800r	-1.30	-	0.223	0.68
Th 3-4	2.83	0.946	0.078	4.20	1.5			-0.60	-	0.055	0.49
M 3-38	2.06	0.968	0.238	3.49	1.8	15	2400r	-1.05	-	0.143	1.04
M 3-8	1.93	0.860	-	3.73	3.2			-1.48	4.50	0.095	0.53
H 1-40	2.52	0.939	-	4.26	3.0	20	1000	-1.23	-	0.044	0.66
M 2-23	1.28	0.924	-	4.00	1.0	14	1500r	-0.15	4.73	0.108	0.02
He 2-260	0.76	0.012	-	4.16	1.0	17	3500	-0.65	4.41	0.2	0.74
H 1-32	1.63	0.787	-	3.74	1.0	11	1900r	-1.37	-	0.012	0.07
H 1-35	1.33	0.525	0.002	4.26	1.5	10	3100	-0.26	4.65	0.103	0.20

Notes. The reported quantities are: logarithmic extinction at H (Col. 2); ionization parameters O⁺⁺/(O⁺+O⁺⁺) and He⁺⁺/(He⁺+He⁺⁺) (Cols. 3 and 4); electron density from [S II] 6717/6731 line ratio (Col. 5); nebular diameter (Col. 6); nebular expansion velocity (Col. 7); kinematic age (Col. 8); H surface brightness (Col. 9); stellar temperature from Zanstra hydrogen method (Col. 10); mass of ionized nebular gas (Col. 11) and mass of dust (Col. 12).
Kinematic ages t are from Gesicki & Zijlstra (2000) and Gesicki et al. (2006) or calculated assuming distance 8.5 kpc (r) or from Shklovski method (s).

References.  - Robinson et al. (1982), - Gesicki & Zijlstra (2000), - Gesicki et al. (2006), - Richer et al. (2008).