Epic variable star 50 EP

HD 173297

RA 281.3229° · Dec -20.6474° · star

Loading sky survey…

🌌 View in 3D star map

Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 7 badges

50 pts · Epic

Epic 78 pts → Anomaly

Supergiant +18
Strongly variable +10
Toward the galactic centre +8
Variable star +5
On the zodiac +3
Yellow-white F-type star +3
A named variable star +3

Total score 50

28 more points to reach Anomaly.

Badges

Variable star · +5
Toward the galactic centre · +8
On the zodiac · +3
Yellow-white F-type star · +3
Supergiant · +18
Strongly variable · +10
A named variable star · +3

Trivia

What it actually is

Spectral class. Its spectrum reads F8Ib/II — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Where it is in life. It is a supergiant, hundreds of times wider than the Sun.
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 7.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Sagittarius.
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 July — that's when to go looking.

Its true colour

Its true colour. Measured through blue and visual filters it comes out yellow (B−V 0.8) — almost exactly the Sun's own shade — a stellar twin in colour, if not in size.
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: -12.55
bv: 0.773
constellation: Sgr
luminosity: 9120108.3936
mag: 7.45
name: HD 173297
spect: F8Ib/II
var amplitude: 0.71
var designation: V350
var max: 7.092
var min: 7.802

Nearby objects

About HD 173297

HD 173297 is an epic variable star. It sits in the constellation Sgr, shines at apparent magnitude 7.45 and has spectral type F8Ib/II.

Its spectrum reads F8Ib/II — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 173297 in the constellation Sgr. At apparent magnitude 7.45, it is an easy target for binoculars.

Like any astronomical target, HD 173297 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 173297 is an epic variable star

HD 173297 scores 50 points on Spacedle's rarity scale, which places it in the epic tier. Another 28 points would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, Toward the galactic centre, On the zodiac, Yellow-white F-type star, Supergiant, 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.