1 Arietis, also registered as Struve 174, is a tight double star in the constellation Aries. The pair is best viewed in winter with at least a small telescope.
While 1 Arietis is not as bright or popular as the double star Gamma Arietis (Mesarthim), it still is an attractive target for those backyard astronomers sailing through Aries. Observers will enjoy the fact that splitting this tight double of 2.8 arcseconds is a nice, but double challenge, with decent seeing conditions. Also, the pair delivers some nice colors. A quote from a user on Cloudy Nights shares the following: “Sissy Haas in her book, Double Stars for Small Telescopes, writes that the pair are ‘bright Sun yellow and pale ocean blue’; Webb says, ‘Gold, very blue,’ Smyth, ‘Topaz yellow, smalt blue.'”1
The primary star is a magnitude 6.40 classified as a K1 III star, while the fainter companion sits at magnitude 7.20 and is classified as an A6 V star. The stars lie almost 600 light years away from us.
Historically speaking, William Herschel first recorded 1 Arietis on November 22, 1782.
My Observations
| Date | January 28, 2022 |
| Time | 7:50 p.m. |
| Location | Seattle, WA |
| Magnification | 338x |
| Scope | Meade 8″ SCT |
| Eyepiece | 12mm (with Barlow) |
| Seeing | Above Average |
| Transparency | Above Average |
This is a fine, very close double. The primary looks to me reddish/yellow in color, while the secondary star seems mostly white. However, as I stare longer at the pair, I believe the secondary’s color is closer to a light blue or light green hue. This pair is pretty dim with my Barlow attached to my 12mm eyepiece, but at least I can still split the stars.
Key Stats
| Constellation | Aries |
| Best Viewing | Winter |
| Visual Magnitude | +6.3 | +7.2 |
| Absolute Visual Magnitude | -.45 |
| Separation | 2.9″ | 521 AU |
| Position Angle | 164° |
| Distance from Earth | 590 ly |
| Orbital Period | Unknown |
| Milky Way Location | Orion Spur |
| My Viewing Grade | A- |
| Designations | 1 Ari, HR 530, SAO 74966, HIP 8544, Struve 174 (STF 174) |
Other Observations in Aries
Sources and Notes
Banner adapted from an illustration created by Pablo Budassi. The illustration is licensed under the Creative Commons Attribution-Share Alike 4.0 International license. Full details here.
Mauigazer. “The Colors of 1 Aries, Struve 174 – Double Star Observing.” Cloudy Nights, 13 Oct. 2017, https://www.cloudynights.com/topic/594827-the-colors-of-1-aries-struve-174/.Sketch by Wayne McGraw
The Garden Astronomer 