In the winter constellation of Taurus lies HR 1997, a reasonably faint binary you can see with any moderate backyard telescope. The good news is that the pair of stars lie far apart, so high magnification is not needed to split the two.
HR 1997’s primary star has a magnitude of +6, so it will appear pretty bright in your telescope. The star itself is classified as a B9Vn star with a blue-white hue. The dimmer secondary star makes it home 75 arcseconds away and shines at a magnitude of +8.3, giving it an easy visual separation in your scope.
Most astronomy sources refer to HR 1997 as a multiple-star system. In fact, another star is nestled by the bright primary that is only .1 arcseconds away, shining at a magnitude of 7.6. While this pair is practically unable to resolve in telescopes, at least you can enjoy the wider pair.
My Observations
| Date | January 27, 2024 |
| Time | 7:34 p.m. |
| Location | Seattle, WA |
| Magnification | 113x |
| Scope | Meade 8″ SCT |
| Eyepiece | 18mm |
| Seeing | Average |
| Transparency | Average |
The primary star shines bright in my eyepiece with a white hue, though it may have a tinge of blue. The dimmer secondary star lies a reasonable distance away, even with my 18mm eyepiece. Other than these characteristics, I find this pair unremarkable.
Key Stats
| Constellation | Taurus |
| Best Viewing | Winter |
| Visual Magnitude | +6 | +8.3 |
| Separation | 75″ |
| Position Angle | 162° |
| Spectral Class | B9Vn |
| Milky Way Location | Orion Spur |
| My Viewing Grade | B- |
| Designations | SAO 77578, ADS 4392, HR 1997, HD 38693, HIP 27421, BD+20 1105 |
Sources and Notes
The Banner was 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.
Sketch by Wayne McGraw
The Garden Astronomer 