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Common star 19 EP

HR 3878

RA 146.3417° · Dec -30.2028° · star

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Score breakdown

· 4 badges
19 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • Star +3
Total score 19

3 more points to reach Uncommon.

Badges

  • Star · +3
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B0IV — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.

Find it in the sky

  • How to spot it. At magnitude 6.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Antlia.
  • 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 February — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out blue-white (B−V -0.1) — the hallmark of a surface far hotter than the Sun's.
  • Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 12240 K, against the Sun's 5778 K.

Properties

absmag
-13.55
bv
-0.137
constellation
Ant
luminosity
22908676.5277
mag
6.45
name
HR 3878
spect
B0IV

Nearby objects

About HR 3878

HR 3878 is a common star. It sits in the constellation Ant, shines at apparent magnitude 6.45 and has spectral type B0IV.

Its spectrum reads B0IV — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HR 3878 in the constellation Ant. At apparent magnitude 6.45, it is an easy target for binoculars.

Like any astronomical target, HR 3878 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 HR 3878 is a common star

HR 3878 scores 19 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Hot blue B-type star, Subgiant (leaving the main sequence) and Blue-white 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.