A Nice Double Star Target For May!
Alrakis (alternately Arrakis), Mu Draconis (μ Draconis, abbreviated Mu Dra, μ Dra) – 21 Draco – Hipparchus 83608.
Observing in NYC can be a challenge but this 4.9 magnitude star is relatively easy to find by star hopping, even from Queens. With binoculars, you can locate it from Manhattan, and then point your telescope to it. It is a beautiful cat’s-eye double of perfectly matched brightness and white color. I was able to easily split it at 132X with my 115mm Brashear f/15.
The Position Angle (PA) appeared almost exactly N-S. Stelle Doppie lists the current PA as 357, so I knew I was looking at the correct double. The separation is currently ~2.60” and anyone with a 70 mm telescope or larger can split this one.
The apparent visual magnitudes of A and B are 5.66 and 5.69, below the local limit of mag 4 in the city, but you can see it in a 30mm finder scope. This is a very fine double star that is a perfect target for a beginning observer, even in the city.
To star-hop to it, locate the head of Draco, in the East. It’s rising above the horizon in the NE, 15º degrees above Vega. Hang a left about five degrees. That puts you right into Draco’s head. The two bright stars, vertically aligned are Eltanin and above it, Rastaban.
Draw a mental line through them and follow that up the same distance as their separation and from there, look to the left (towards Polaris) and the first bright star you come to is Alrakis.