Uncommon star 23 EP

HD 153889

RA 255.8994° · Dec -34.5740° · star

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Score breakdown

· 5 badges

23 pts · Uncommon

Uncommon 34 pts → Rare

Deep red star +8
Giant star +6
Star +3
On the zodiac +3
Orange K-type star +3

Total score 23

11 more points to reach Rare.

Badges

Star · +3
On the zodiac · +3
Orange K-type star · +3
Giant star · +6
Deep red star · +8

Trivia

Hard to believe

True brightness. It pours out about 2.2 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 K2/K3III: — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

Find it in the sky

How to spot it. At magnitude 9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Scorpius.
Southern sky. It rides the southern half of the sky — an easier target the further south you are.
Best time of year. It stands highest in the middle of the night around June — that's when to go looking.

Its true colour

Its true colour. Measured through blue and visual filters it comes out deep orange-red (B−V 1.6) — one of the coolest surfaces a star can have while still fusing.

By the numbers

Surface temperature. Its colour puts the surface at roughly 3600 K, against the Sun's 5778 K.

What's in a name

Its catalogue. The HD number is from the Henry Draper Catalogue, in which Annie Jump Cannon personally classified the spectra of nearly 400,000 stars — still the largest such feat by one person.

Properties

absmag: -11.03
bv: 1.635
constellation: Sco
luminosity: 2249054.6058
mag: 8.97
name: HD 153889
spect: K2/K3III:

Nearby objects

About HD 153889

HD 153889 is an uncommon star. It sits in the constellation Sco, shines at apparent magnitude 8.97 and has spectral type K2/K3III:.

Its spectrum reads K2/K3III: — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

How to see it

Look for HD 153889 in the constellation Sco. At apparent magnitude 8.97, it is an easy target for binoculars.

Like any astronomical target, HD 153889 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 153889 is an uncommon star

HD 153889 scores 23 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 11 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, On the zodiac, Orange K-type star, Giant star and Deep red star — 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.