NGC 6401

RA:

17:38:36.60

Dec:

-23:54:34.2

Distance from Sun:

34.6 kly

Distance from Galactic Center:

8.8 kly

Apparent Diameter:

12.1 arc min

Brightness:

9.45 mag vis

Radial Velocity:

-65.0 +/- 8.6 km/s

Diameter:

ly

Abs. Mag:

-7.90 Mag vis

This globular cluster was first taken for a bright nebula by William Herschel, and cataloged accordingly as H I.44. John Herschel also described it as a nebula, as he apparently couldn't resolve it into stars either.

In 1977, Peterson (1977) announced the finding of another planetary nebula in the neighborhood, and perhaps associated with globular cluster NGC 6401 in Ophiuchus; this planetary nebula candidate was cataloged as Peterson 1 (Pt 1; PK 004+03.1). However, Acker and Stenholm (1990) found that this object exhibits a red stellar continuum - thus is not a planetary nebula but a symbiotic star.

• Catalog of Variable Stars in NGC 6401 (Christine Clement)

• Acker, A. and Stenholm, B., 1990. Misclassified planetary nebulae. Astronomy and Astrophysics Supplement Series, Vol. 86, No. 2 (Dec 1990), pp. 219-225. [ADS: 1990A&AS...86..219A]
• Peterson, A.W., 1977. A new planetary nebula. Publications of the Astronomical Socieaty of the Pacific, Vol. 89, pp. 129-130. [ADS: 1977PASP...89..129P]