A Harvest of Nearby Stars

 Early-morning observing sessions on Oct 23 and 25 yielded images of nine of the nearest stars. They are:

• (3) Wolf 359
• (5) Sirius
  
• (9) Epsilon Eridani (Ran)
• (13) Procyon
• (17) DX Cancri
• (20) Luyten 372-58 (GJ 1061)
• (22) Luyten's Star
• (24) Kapteyn's Star
  
• (29) Ross 614

 The number in parentheses is each star's rank in closeness to our solar system.  Three stars in the list are visible with the naked-eye (Sirius, Ran, Procyon), the rest are red dwarf stars that require a telescope.  Sirius is the brightest star in the sky and Procyon is number 8.

Below is a finder chart showing the relative positions in the sky.  Two stars that I discussed in previous posts (Teegarden's Star and van Maanen's Star) also show up on this chart.

credit: SkySafariAstronomy.com

Here is a real-life image of Orion rising over the not-so-distant hills:

Sony A7iii + Laowa 15mm f/2 + softon filter.  ISO 1600, 30s.

I have already discussed Wolf 359 in a previous post, so I will take the remaining eight stars in order.

Sirius

Sirius (Alpha Canis Majoris) is the brightest star in the sky at magnitude -1.4 and is 8.7 ly distant, the fifth closest star system to ours. It is about twice the mass and 25 times the luminosity of our sun.  It is a double star with a white dwarf companion that is an observational challenge for amateur astronomers.  The companion is actually quite bright at magnitude 8.4, but in a telescopic view it is overwhelmed by the brightness of the main star.  This companion star was once more massive and more luminous than Sirius itself and was a red giant star in the Cretaceous Period 120 million years ago.

 

Sirius.  E-P5 + Rokinon 135mm f/2. ISO 1600, 30 s.

 Ran (Epsilon Eridani)

Ran is very similar to our sun, with about 80% of the mass and one third the luminosity.  It is 10.5 ly away.  At magnitude 3.7, it is the third closest star visible to the naked eye (after Alpha Centauri and Sirius).  It is the 9th closest star system. 

 

Many of the brighter stars have names with roots in antiquity, but Epsilon Eridani did not have an official name until 2015 when Ran (Norse god of the sea) was chosen in a contest sponsored by the International Astronomical Union.

Epsilon Eridani (Ran).  E-P5 + Rokinon 135mm f/2. ISO1600, 60s.

Procyon

Procyon (Alpha Canis Minoris) is one corner of the "Winter Triangle", along with Sirius and Betelgeuse.  It is 11.4 ly away, the 13th closest star system, and is the 8th brightest star at magnitude 0.3.  Like Sirius, Procyon has a white dwarf companion. 

Procyon.  E-P5 + Rokinon 135mm f/2, ISO1600, 60s.

DX Cancri

DX Cancri is a magnitude-14.8 red dwarf star in the constellation Cancer.  At 11.7 ly it is the 17th closest star system.  With a mass of about 9% of our sun, it has an estimated hydrogen-burning lifetime of around 8 trillion years.

 

The image below is a 1-deg field, upscaled by x2 from the original.  DX Cancri is a faint dot at the center of the circle with a brighter star just up and to the left.

DX Cancri.  E-P5 + Rokinon 135mm f/2.  ISO1600, 60s.

 GJ 1061 (Luyten 372-58)

German astronomer Wilhelm Gliese published the Gliese Catalogue of Nearby Stars in 1957.  An extension to the second edition of this catalog was published in 1979 in collaboration with his successor Hartmut Jahreiß.  Stars referenced in this later edition are prefixed with the letters "GJ".  Willem Jacob Luyten was a Dutch-American astronomer who cataloged thousands of high-proper-motion stars.  Since nearby stars also exhibit high proper motion they will appear in several catalogs with overlapping characteristics.

 

GJ 1061 is a magnitude-13.1 red dwarf star 12 ly distant, the 20th closest star system.  It has 1/8 the mass of the sun and does not exhibit flares, unlike most red dwarf stars.  It has two known planets.

 

 

GJ 1061. E-P5 + Rokinon 135mm f/2.  ISO1600, 60s. 2° field of view.

Luyten's Star

Luyten's Star is a magnitude-9.9 magnitude red dwarf 12.3 ly distant and the 22nd closest system to ours.  Its position in the sky is just under 3° from Procyon.  In space, it is only 1.2 ly from Procyon.  If we were that close to Procyon it would shine at magnitude -4.5, sixteen times brighter than Sirius.  Luyten's Star is a fairly large red dwarf with a mass of about 29% of our sun.  It has two known planets and two more suspected.

Luyten's Star.  E-P5 + Rokinon 135mm f/2. ISO1600, 60s.

Kapteyn's Star

Kapteyn's Star has a proper motion of 8.7"/y,  which was the highest known at the time of its discovery by Dutch astronomer Jacobus Kapteyn in 1898.  In 1916 Barnard's Star was discovered to have a proper motion of 10.35"/yr, moving Kapteyn's Star to second place.  Kapteyn's Star is a magnitude-8.8 red dwarf at a distance of 12.8 ly, 24th closest to the solar system.  It has a mass of about 28% of our sun.

Capturing an image of Kapteyn's Star was a challenge because at this latitude its maximum distance above the horizon is only 7.3°.  Wildfire smoke and local hills interfered with the first two attempts.  Significant green airglow at this elevation also forced a shorter exposure time.

Kapteyn's Star.  E-P5 + Rokinon 135mm f/2. ISO1600, 40s.

Ross 614

Astronomer Frank Ross was the successor of E.E. Barnard at Yerkes Observatory, home of the 40" Alvan Clark refractor, the world's largest.  Ross repeated many of the photographic surveys inherited from Barnard and discovered more than 1000 high-proper motion stars by comparing the newer to the older images.  Four of the nearest 32 star systems are known by their Ross catalog numbers (Ross 154, Ross 248, Ross 128, Ross 614).

Ross 614 lies near the center of the "Winter Triangle".  It is a red-dwarf double star with two components of magnitude 11.1 and 14.2.  At 13.4 ly it is the 29th closest star system. The two stars have masses of about 22% and 11% of our sun.

Ross 614. E-P5 + Rokinon 135mm f/2. ISO 1600, 60 s.