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Uncommon variable star 26 EP

HD 178359

RA 287.0573° · Dec 1.2987° · star

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Score breakdown

· 5 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Strongly variable +10
  • Variable star +5
  • Subgiant (leaving the main sequence) +5
  • Yellow-white F-type star +3
  • A named variable star +3
Total score 26

8 more points to reach Rare.

Badges

  • Variable star · +5
  • Yellow-white F-type star · +3
  • Subgiant (leaving the main sequence) · +5
  • Strongly variable · +10
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads F5IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • 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.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

Find it in the sky

  • How to spot it. At magnitude 7.1 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Aquila.
  • 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 July — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out orange (B−V 1.3) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 4180 K, against the Sun's 5778 K.

Properties

absmag
-12.91
bv
1.27
constellation
Aql
luminosity
12705741.0521
mag
7.09
name
HD 178359
spect
F5IV
var amplitude
0.91
var designation
TT
var max
6.791
var min
7.701

Nearby objects

About HD 178359

HD 178359 is an uncommon variable star. It sits in the constellation Aql, shines at apparent magnitude 7.09 and has spectral type F5IV.

Its spectrum reads F5IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 178359 in the constellation Aql. At apparent magnitude 7.09, it is an easy target for binoculars.

Like any astronomical target, HD 178359 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 178359 is an uncommon variable star

HD 178359 scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Yellow-white F-type star, Subgiant (leaving the main sequence), Strongly variable and A named variable 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.