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Trash star 11 EP

HD 47217

RA 99.6662° · Dec 26.4999° · star

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Score breakdown

· 3 badges
11 pts · Trash
Trash 15 pts → Common
  • White A-type star +5
  • Star +3
  • On the zodiac +3
Total score 11

4 more points to reach Common.

Badges

  • Star · +3
  • On the zodiac · +3
  • White A-type star · +5

Trivia

Hard to believe

  • True brightness. It pours out about 2.6 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 A0 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

Find it in the sky

  • How to spot it. At magnitude 8.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Gemini.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around December — 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.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 9330 K, against the Sun's 5778 K.

Properties

absmag
-11.2
bv
0.07
constellation
Gem
luminosity
2630267.9919
mag
8.8
name
HD 47217
spect
A0

About HD 47217

HD 47217 is a trash star. It sits in the constellation Gem, shines at apparent magnitude 8.8 and has spectral type A0.

Its spectrum reads A0 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 47217 in the constellation Gem. At apparent magnitude 8.8, it is an easy target for binoculars.

Like any astronomical target, HD 47217 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 47217 is a trash star

HD 47217 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, On the zodiac and White A-type 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.