HD 107146     SAO 100038   HIP 60074
RA (2000) = 12 19 06.502     Dec (2000) = +16 32 53.863
SpT = G2V    V = 7.07mag    d = 28.51 pc
Proper Motion (mas/yr) = -174.16 -148.90

This is an optical Hubble Space Telescope image of dust scattered light (reflection nebulosity) around the G2V star HD 107146. The central star is actually blocked by a small black spot in the optical path of Hubble's camera, producing an artificial eclipse of the star, and thus revealing the faint surrounding material that is illuminated by the star. In contrast to the other debris disks, this is the first resolved image of a disk around a star like the Sun. However, at a distance of 28.5 pc (94 light year), HD 107146 is significantly farther away than Beta Pic, Vega, Fomalhaut, etc. The elliptical object seen to the lower right of HD 107146 is a background galaxy.

The dust around HD 107146 appears to be something like a donut in shape, because the disk is inclined almost face-on to our line of sight (actually, 25 degrees from face-on). The disk is seen as close as 60 AU from the star, and the dust is concentrated at approximately 130 AU radius. The outer radius is approximately 185 AU.

Basic facts about HD 107146

1) structure is a ring with inner and outer radii of 60 and 185 AU, respectively.

2) scattered light color is red relative to the star (V - I = 0.4 mag).

3) the characteristic dust temperature is 40 - 50 K.

4) total dust mass is 0.1 - 0.4 Earth mass

5) asymmetric brightness distribution can be simulated by an asymmetric scattering phase function such as a Henyey-Greenstein function with asymmetry parameter = 0.2 - 0.3.

6) ring is seen 25 degrees from face-on from our point of view.