Uncommon star 25 EP

HD 82819

RA 143.6728° · Dec 8.1875° · star

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Score breakdown

· 5 badges

25 pts · Uncommon

Uncommon 34 pts → Rare

Deep red star +8
Giant star +6
Cool red M-type star +5
Star +3
On the zodiac +3

Total score 25

9 more points to reach Rare.

Badges

Star · +3
On the zodiac · +3
Cool red M-type star · +5
Giant star · +6
Deep red star · +8

Trivia

What it actually is

Spectral class. Its spectrum reads M3III: — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.

Find it in the sky

How to spot it. At magnitude 7.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Leo.
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 February — 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 1.7) — one of the coolest surfaces a star can have while still fusing.

By the numbers

Surface temperature. Its colour puts the surface at roughly 3550 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: -12.65
bv: 1.67
constellation: Leo
luminosity: 10000000
mag: 7.35
name: HD 82819
spect: M3III:

Nearby objects

About HD 82819

HD 82819 is an uncommon star. It sits in the constellation Leo, shines at apparent magnitude 7.35 and has spectral type M3III:.

Its spectrum reads M3III: — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.

How to see it

Look for HD 82819 in the constellation Leo. At apparent magnitude 7.35, it is an easy target for binoculars.

Like any astronomical target, HD 82819 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 82819 is an uncommon star

HD 82819 scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 9 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, On the zodiac, Cool red M-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.