Instrument

12.5" RCOS @ ~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at 1.32 and 3.16 arcsec/pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ FW8 filter wheel & AstroDon Gen-2 RGB filters.

Acquisition Data

6/11/2011 to 7/2/2011 Chino Valley, AZ. with CCDAutoPilot3 & CCDSoft.  AOL guided

Exposure

eXcalibrator RGB ratios are 1.00, 1.08 & 1.26

Software & Processing Notes

• CCDSoft, CCDStack, PixInsight, Photoshop CS6.

• eXcalibrator v5.0 for (g:r) color balancing, using 63 stars from the APASS database.

• CCDBand-Aid to repair KAI-11000M vertical bars.

• CCDStack to calibrate the sub exposures.

• PixInsight to register, normalize, data reject, stack, create the RGB, gradient removal and non-linear stretching with HistogramTransformation.

• PhotoShop for the final touch-up.

Comment

North is to the top.

R Leporis, sometimes called Hind's Crimson Star, is a variable star in the constellation Lepus. Its magnitude varies from +5.5 to +11.7, with a period of 427 days. Being a carbon star, it appears distinctly red. As the star dims it becomes visually redder.

With its two bluish neighbors, R Leporis presents a spectacular view with a small telescope.

To objectively quantify star color, astronomers use the B-V color index. To obtain this value, they use B (blue) and V (visual or essentially green) filters. The color index is obtained by simply subtracting the V magnitude from the B. Blue-white Spica has a B–V index of –0.3 and our slightly yellow Sun is at +0.65. R Leporis is very red, with a B-V value of +5.7.