Mu Draconis, also known as the star Alrakis, is a multiple star system near Draco’s head and serves as the tip of the dragon’s tongue. While dim from the suburbs, the star is viewable with the naked eye but as only a single bead of light. But take out a telescope and use considerable magnification. Right away, the scene changes as the single star split into two—a fantastic double star appears.
What sets Mu Draconis apart from many double stars is that both stars are close in both brightness and color. In fact, they have almost mirrored images of each other, and this effect is powerful. Author Bob King with Sky & Telescope captures it well stating there’s “something mesmerizing about seeing two bright, equal stars paired.” I also agree with Bob’s assessment that Mu Draconis is an “exquisite” double.
But Mu Draconis is one of two star systems like this in Draco. A small trip away and one arrives at Nu Draconis with its two equally bright stars! This makes both Mu and Nu Draconis must-see destinations for backyard astronomers.
Even though this pair may look like two tiny eyes looking back at you (see my description below), they are both around 1.5 times the size of our sun and 1.3 times the mass. It’s just that they lie 90 light years away.
My Observations
| Date | June 25, 2021 |
| Time | 11:06 p.m. |
| Location | Seattle, WA |
| Magnification | 254x |
| Scope | Meade 8″ SCT |
| Eyepiece | 8mm |
| Seeing | Average |
| Transparency | Above Average |
Wow. A minute ago, my scope brought Mu Draconis into view, but it appeared as one star. As I changed out the 25mm eyepiece to 12mm, I noticed it elongated, and then I switched in the 8mm and have sketched from there. The stars are of equal brightness and are white in color. It’s like a small insect is peering back at me from deep in the heavens.
Key Stats
| Constellation | Draco |
| Best Viewing | Late Spring |
| Visual Magnitude | +5.6 | +5.6 |
| Absolute Visual Magnitude | +3.44 |
| Distance from Earth | 90 ly |
| Separation | 2.6 ″ | 90 AU |
| Orbital Period | 812 yrs |
| Milky Way Location | Orion Spur |
| My Viewing Grade | A |
Sources and Notes
Banner photo by David Ritter and shared under the Creative Commons Attribution-Share Alike 4.0 International license.
Sketch by Wayne McGraw
Double date with a dragon. Sky & Telescope. (2019, April 18). Retrieved April 28, 2022, from https://skyandtelescope.org/observing/double-date-with-a-dragon/
AKA: SAO 30239, HD 154905
The Garden Astronomer 