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Uncommon star 27 EP

HD 39557

RA 88.3631° · Dec 0.7792° · star

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Score breakdown

· 5 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Distant (over 1,000 light-years) +6
  • In Orion's hunting ground +6
  • Hot blue B-type star +6
  • Giant star +6
  • Star +3
Total score 27

7 more points to reach Rare.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • In Orion's hunting ground · +6
  • Hot blue B-type star · +6
  • Giant star · +6

Trivia

What it actually is

  • Spectral class. Its spectrum reads B5III — 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 giant. It has already exhausted its core hydrogen and swollen up enormously in response.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 9.1 you'll want a small backyard telescope, over in Orion.
  • 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 December — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 28.1 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.618
bv
0.419
constellation
Ori
dist ly
1598.804
luminosity
49.2947
mag
9.07
name
HD 39557
spect
B5III

About HD 39557

HD 39557 is an uncommon star. It lies about 1,598.8 light-years from Earth, sits in the constellation Ori, shines at apparent magnitude 9.07 and has spectral type B5III.

Its spectrum reads B5III — 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 39557 in the constellation Ori. At apparent magnitude 9.07, a small backyard telescope will bring it into view.

Like any astronomical target, HD 39557 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 39557 is an uncommon star

HD 39557 scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Distant (over 1,000 light-years), In Orion's hunting ground, Hot blue B-type star and Giant 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.