Rare variable star 39 EP

HD 190642

RA 301.6225° · Dec -18.3079° · star

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Score breakdown

· 8 badges

39 pts · Rare

Rare 50 pts → Epic

Toward the galactic centre +8
Sun-like G-type star +8
Distant (over 1,000 light-years) +6
Variable star +5
Gently variable +4
On the zodiac +3
A named variable star +3
Main-sequence star +2

Total score 39

11 more points to reach Epic.

Badges

Variable star · +5
Distant (over 1,000 light-years) · +6
Toward the galactic centre · +8
On the zodiac · +3
Sun-like G-type star · +8
Main-sequence star · +2
Gently variable · +4
A named variable star · +3

Trivia

What it actually is

Spectral class. Its spectrum reads G5V — a G-type star: the very same spectral class as our own Sun.
Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
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.

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 8.1 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.

Could we get there?

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

Properties

absmag: 0.554
bv: 0.992
constellation: Sgr
dist ly: 1048.7331
luminosity: 52.2878
mag: 8.09
name: HD 190642
spect: G5V
var amplitude: 0.21
var designation: V4429
var max: 7.971
var min: 8.181

Nearby objects

About HD 190642

HD 190642 is a rare variable star. It lies about 1,048.7 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 8.09 and has spectral type G5V.

Its spectrum reads G5V — a G-type star: the very same spectral class as our own Sun.

How to see it

Look for HD 190642 in the constellation Sgr. At apparent magnitude 8.09, it is an easy target for binoculars.

Like any astronomical target, HD 190642 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 190642 is a rare variable star

HD 190642 scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Distant (over 1,000 light-years), Toward the galactic centre, On the zodiac, Sun-like G-type star, Main-sequence star, Gently 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.