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Trash star 13 EP

HD 74721

RA 131.4969° · Dec 13.2635° · star

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Score breakdown

· 4 badges
13 pts · Trash
Trash 15 pts → Common
  • White A-type star +5
  • Star +3
  • On the zodiac +3
  • Main-sequence star +2
Total score 13

2 more points to reach Common.

Badges

  • Star · +3
  • On the zodiac · +3
  • White A-type star · +5
  • Main-sequence star · +2

Trivia

Hard to believe

  • True brightness. It pours out about 2.8 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 A0V — 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.
  • 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 8.7 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cancer.
  • 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 January — 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) — 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
-11.3
bv
0.042
constellation
Cnc
luminosity
2884031.5031
mag
8.7
name
HD 74721
spect
A0V

About HD 74721

HD 74721 is a trash star. It sits in the constellation Cnc, shines at apparent magnitude 8.7 and has spectral type A0V.

Its spectrum reads A0V — 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 74721 in the constellation Cnc. At apparent magnitude 8.7, it is an easy target for binoculars.

Like any astronomical target, HD 74721 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 74721 is a trash star

HD 74721 scores 13 points on Spacedle's rarity scale, which places it in the trash tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, On the zodiac, White A-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.