Betelgeuse
Angular diameter estimates

Betelgeuse

Section Title: Angular diameter estimates
Table Section Text: None

Article	Year	Telescope	#	Spectrum	λ (μm)	∅ (mas)	Radii @ 197±45 pc	Notes

Michelson	1920	Mt-Wilson	1	Visible	0.575	47.0 ± 4.7	3.2–6.3 AU	Limb darkened +17% = 55.0

Bonneau	1972	Palomar	8	Visible	0.422–0.719	52.0–69.0	3.6–9.2 AU	Strong correlation of ∅ with λ

Balega	1978	ESO	3	Visible	0.405–0.715	45.0–67.0	3.1–8.6 AU	No correlation of ∅ with λ

1979	SAO	4	Visible	0.575–0.773	50.0–62.0	3.5–8.0 AU

Buscher	1989	WHT	4	Visible	0.633–0.710	54.0–61.0	4.0–7.9 AU	Discovered asymmetries/hotspots

Wilson	1991	WHT	4	Visible	0.546–0.710	49.0–57.0	3.5–7.1 AU	Confirmation of hotspots

Tuthill	1993	WHT	8	Visible	0.633–0.710	43.5–54.2	3.2–7.0 AU	Study of hotspots on 3 stars

1992	WHT	1	NIR	0.902	42.6 ± 0:03	3.0–5.6 AU

Gilliland	1995	HST	UV	0.24–0.27	104–112	10.3–11.1	FWHM diameters

0.265–0.295	92–100	9.1–9.8

Weiner	1999	ISI	2	MIR (N Band)	11.150	54.7 ± 0.3	4.1–6.7 AU	Limb darkened = 55.2 ± 0.5

Perrin	1997	IOTA	7	NIR (K band)	2.200	43.33 ± 0.04	3.3–5.2 AU	K and L bands, 11.5 μm data contrast

Haubois	2005	IOTA	6	NIR (H band)	1.650	44.28 ± 0.15	3.4–5.4 AU	Rosseland diameter 45.03 ± 0.12

Hernandez	2006	VLTI	2	NIR (K band)	2.099–2.198	42:57 ± 0:02	3.2–5.2 AU	High precision AMBER results.

Ohnaka	2008	VLTI	3	NIR (K band)	2.280–2.310	43.19 ± 0.03	3.3–5.2 AU	Limb darkened 43.56 ± 0.06

Townes	1993	ISI	17	MIR (N band)	11.150	56.00 ± 1.00	4.2–6.8 AU	Systematic study involving 17 measurements at the same wavelength from 1993 to 2009

2008	ISI	MIR (N band)	11.150	47.00 ± 2.00	3.6–5.7 AU

2009	ISI	MIR (N band)	11.150	48.00 ± 1.00	3.6–5.8 AU

Ohnaka	2011	VLTI	3	NIR (K band)	2.280–2.310	42.05 ± 0.05	3.2–5.2 AU	Limb darkened 42.49 ± 0.06

Harper	2008	VLA	Also noteworthy, Harper et al. in the conclusion of their paper make the following remark: "In a sense, the derived distance of 200 pc is a balance between the 131 pc (425 ly) Hipparcos distance and the radio which tends towards 250 pc (815 ly)"—hence establishing ± 815 ly as the outside distance for the star.

Sentence(s)

Limb darkening had a diameter of 55.2 ± 0.5 mas.

final_sentence: Limb darkening had a diameter of 55.2 ± 0.5 mas.