double star distance & maximum separation
parsec distance and arcsecond angular separation (ρ) by apparent magnitude (v.m), orbital radius (AU) & primary dwarf spectral type

O8V B5V A0V A5V F0V F5V G0V G5V K0V K5V M0V

M sol 40 10.5 2.90 2.25 1.60 1.33 1.05 0.93 0.80 0.65 0.50

v.M -4.4 -1.1 1.4 2.1 2.6 3.4 4.4 5.2 5.9 8.0 9.2

v.m 4 distance
479 105 33 24 19 13 8 6 4 2 1

orbit 10 0.1 0.2 0.3 0.4 0.5 0.7 1.0 1.3 1.7 4 7

50 0.3 0.8 1.7 2 2 3 5 7 9 22 35

250 1.4 4 9 11 12 17 24 34 44 109 173

1000 6 16 34 43 48 65 96 133 175 7' 11'

5000 28 83 171 217 244 6' 8' 11' 15' 36' 58'

25000 142 7' 14' 18' 20' 28' 40' 56' 74' 181' 288'

v.m 6 distance
1202 263 83 60 48 33 21 14 10 4 2

orbit 10 0.0 0.1 0.1 0.2 0.2 0.3 0.4 0.5 0.7 1.7 3

50 0.1 0.3 0.7 0.9 1.0 1.3 1.9 3 4 9 14

250 0.6 1.7 3 4 5 7 10 13 18 43 69

1000 2 7 13 17 19 26 38 53 70 171 272

5000 11 33 68 86 97 132 193 268 6' 14' 23'

25000 57 165 6' 7' 8' 11' 16' 22' 29' 72' 115'

v.m 8 distance
3020 661 209 151 120 83 52 36 26 10 6

orbit 10 0.0 0.0 0.1 0.1 0.1 0.1 0.2 0.2 0.3 0.7 1.1

50 0.0 0.1 0.3 0.3 0.4 0.5 0.8 1.1 1.4 3 5

250 0.2 0.7 1.4 1.7 1.9 3 4 5 7 17 27

1000 0.9 3 5 7 8 10 15 21 28 68 108

5000 4 13 27 34 39 52 77 107 140 6' 9'

25000 22 66 136 172 193 263 6' 9' 12' 29' 46'

v.m 10 distance
7586 1660 525 380 302 209 132 91 66 25 14

orbit 10 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.1 0.3 0.4

50 0.0 0.1 0.1 0.1 0.2 0.2 0.3 0.4 0.6 1.4 2

250 0.1 0.3 0.5 0.7 0.8 1.0 1.5 2 3 7 11

1000 0.4 1.0 2 3 3 4 6 8 11 27 43

5000 1.8 5 11 14 15 21 31 42 56 137 218

25000 9 26 54 68 77 105 153 213 279 11' 18'

Quoted separations based on constant periods of 22y [10 AU], 250y [50 AU], 2800y [250], 22,000y [1000 AU], 250,000y [5000 AU] and 2,800,000y [25,000 AU].
Separations based on primary star mass (M₁) only, which reduces rigorous angular separation by ~20% in a matching 2M₁ mass system; this compensates for unfavorable orbital inclination and aspect.
To incorporate companion mass under assumption of maximum aspect, multiply angular separation by the following factors for binary magnitude differences or mass ratios: (Δm=0.0, q=1.00) = 1.26, (Δm=1.0, q=0.63) = 1.18, (Δm=2.0, q=0.40) = 1.12, (Δm=3.0, q=0.25) = 1.08, (Δm=4.0, q=0.16) = 1.05.

Nomograms of parsec distance as a function of apparent magnitude and spectral type, for luminosity classes V, III and I.


	O8V	B5V	A0V	A5V	F0V	F5V	G0V	G5V	K0V	K5V	M0V

M sol	40	10.5	2.90	2.25	1.60	1.33	1.05	0.93	0.80	0.65	0.50
v.M	-4.4	-1.1	1.4	2.1	2.6	3.4	4.4	5.2	5.9	8.0	9.2

v.m 4	distance 479	105	33	24	19	13	8	6	4	2	1
orbit 10	0.1	0.2	0.3	0.4	0.5	0.7	1.0	1.3	1.7	4	7
50	0.3	0.8	1.7	2	2	3	5	7	9	22	35
250	1.4	4	9	11	12	17	24	34	44	109	173
1000	6	16	34	43	48	65	96	133	175	7'	11'
5000	28	83	171	217	244	6'	8'	11'	15'	36'	58'
25000	142	7'	14'	18'	20'	28'	40'	56'	74'	181'	288'

v.m 6	distance 1202	263	83	60	48	33	21	14	10	4	2
orbit 10	0.0	0.1	0.1	0.2	0.2	0.3	0.4	0.5	0.7	1.7	3
50	0.1	0.3	0.7	0.9	1.0	1.3	1.9	3	4	9	14
250	0.6	1.7	3	4	5	7	10	13	18	43	69
1000	2	7	13	17	19	26	38	53	70	171	272
5000	11	33	68	86	97	132	193	268	6'	14'	23'
25000	57	165	6'	7'	8'	11'	16'	22'	29'	72'	115'

v.m 8	distance 3020	661	209	151	120	83	52	36	26	10	6
orbit 10	0.0	0.0	0.1	0.1	0.1	0.1	0.2	0.2	0.3	0.7	1.1
50	0.0	0.1	0.3	0.3	0.4	0.5	0.8	1.1	1.4	3	5
250	0.2	0.7	1.4	1.7	1.9	3	4	5	7	17	27
1000	0.9	3	5	7	8	10	15	21	28	68	108
5000	4	13	27	34	39	52	77	107	140	6'	9'
25000	22	66	136	172	193	263	6'	9'	12'	29'	46'

v.m 10	distance 7586	1660	525	380	302	209	132	91	66	25	14
orbit 10	0.0	0.0	0.0	0.0	0.0	0.0	0.1	0.1	0.1	0.3	0.4
50	0.0	0.1	0.1	0.1	0.2	0.2	0.3	0.4	0.6	1.4	2
250	0.1	0.3	0.5	0.7	0.8	1.0	1.5	2	3	7	11
1000	0.4	1.0	2	3	3	4	6	8	11	27	43
5000	1.8	5	11	14	15	21	31	42	56	137	218
25000	9	26	54	68	77	105	153	213	279	11'	18'

Quoted separations based on constant periods of 22y [10 AU], 250y [50 AU], 2800y [250], 22,000y [1000 AU], 250,000y [5000 AU] and 2,800,000y [25,000 AU]. Separations based on primary star mass (M₁) only, which reduces rigorous angular separation by ~20% in a matching 2M₁ mass system; this compensates for unfavorable orbital inclination and aspect. To incorporate companion mass under assumption of maximum aspect, multiply angular separation by the following factors for binary magnitude differences or mass ratios: (Δm=0.0, q=1.00) = 1.26, (Δm=1.0, q=0.63) = 1.18, (Δm=2.0, q=0.40) = 1.12, (Δm=3.0, q=0.25) = 1.08, (Δm=4.0, q=0.16) = 1.05.