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Trash star 11 EP

HD 90643

RA 156.6971° · Dec -51.4085° · star

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Score breakdown

· 3 badges
11 pts · Trash
Trash 15 pts → Common
  • Hot blue B-type star +6
  • Star +3
  • Main-sequence star +2
Total score 11

4 more points to reach Common.

Badges

  • Star · +3
  • Hot blue B-type star · +6
  • Main-sequence star · +2

Trivia

Hard to believe

  • True brightness. It pours out about 3.4 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 B9V — 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 on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.

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 Vela.
  • 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 brilliant white (B−V 0.1) — hotter and whiter than the Sun, the colour of Sirius or Vega.
  • 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.

Properties

absmag
-11.49
bv
0.074
constellation
Vel
luminosity
3435579.479
mag
8.51
name
HD 90643
spect
B9V

Nearby objects

About HD 90643

HD 90643 is a trash star. It sits in the constellation Vel, shines at apparent magnitude 8.51 and has spectral type B9V.

Its spectrum reads B9V — 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 HD 90643 in the constellation Vel. At apparent magnitude 8.51, it is an easy target for binoculars.

Like any astronomical target, HD 90643 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 90643 is a trash star

HD 90643 scores 11 points on Spacedle's rarity scale, which places it in the trash tier. Another 4 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, Hot blue B-type star and Main-sequence 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.