DX Cancri – Red Dwarf Flare Star in Cancer

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: QHY 367c Pro, -20C, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 9x300sec, gain 2800, offset 50, saved as FITS, dithered every 2 images

Darks: 32, -20C, gain 2800, offset 50, saved as FITS

Flats: 64×0.3sec, Tee shirt flats taken at dusk

Average Light Pollution: Red zone, Bortle 8, poor transparency

Lensed Sky Quality Meter: 18.3

Stacking: Average, 1 sigma clip

White Balance: Nebulosity Automatic

Software: SharpCap Pro, Deep Sky Stacker, Nebulosity, Photoshop

DX Cancri is a red dwarf flare star located 11.8 light years away in the direction of Cancer. DX Cancri has only 9% of the sun’s mass and 11% of its diameter and glows a deep red at magnitude 14.8. These lightweight, faint red stars are among the most common in the Milky Way. They are also amazingly long-lived. Because of their low mass they fuse hydrogen into helium at a relatively slow rate and do so very efficiency, resulting in a life span than can be measured in trillions of years. While they are long-lived, they are not necessarily stable. DX Cancri is a flare star, occasionally and unexpectedly brightening as much as five-fold in an event similar to a coronal mass ejection from the sun. Lastly only a few minutes these events are rare and difficult to observe.

This field measures about 0.6 x 0.9 degrees with north up and east to the right. Selected stars are labeled using the AAVSO format with the magnitude shown to the nearest 0.1 magnitude with the decimal omitted. For example, a magnitude 11.2 star is labeled 112.