About HD 289173
HD 289173 is an uncommon star. It sits in the constellation Mon, shines at apparent magnitude 8.53 and has spectral type G3Ib.
Its spectrum reads G3Ib — a G-type star: the very same spectral class as our own Sun.
Uncommon star 29 EP
HD 289173
RA 102.1943° · Dec 2.0095° · star
Score breakdown
· 3 badgesUncommon 34 pts → Rare
- Supergiant +18
- Sun-like G-type star +8
- Star +3
Total score 29
5 more points to reach Rare.
Badges
- Star · +3
- Sun-like G-type star · +8
- Supergiant · +18
Trivia
Hard to believe
- True brightness. It pours out about 3.3 million times as much light as the Sun. It only looks ordinary because it is so far away.
What it actually is
- Spectral class. Its spectrum reads G3Ib — a G-type star: the very same spectral class as our own Sun.
- Where it is in life. It is a supergiant, hundreds of times wider than the Sun.
Find it in the sky
- How to spot it. At magnitude 8.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Monoceros.
- Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
- Best time of year. It stands highest in the middle of the night around January — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out orange (B−V 1.1) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 4580 K, against the Sun's 5778 K.
Properties
- absmag
- -11.47
- bv
- 1.069
- constellation
- Mon
- luminosity
- 3372873.0866
- mag
- 8.53
- name
- HD 289173
- spect
- G3Ib
Nearby objects
How to see it
Look for HD 289173 in the constellation Mon. At apparent magnitude 8.53, it is an easy target for binoculars.
Like any astronomical target, HD 289173 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
Why HD 289173 is an uncommon star
HD 289173 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Sun-like G-type star and Supergiant — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.