About HR 7458
HR 7458 is an uncommon variable star. It sits in the constellation Vul, shines at apparent magnitude 7.01 and has spectral type F8IV.
Its spectrum reads F8IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Uncommon variable star 26 EP
HR 7458
RA 294.1572° · Dec 20.3329° · star
Score breakdown
· 5 badgesUncommon 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 F8IV — 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 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Vulpecula.
- 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 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 1.2) — 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 4310 K, against the Sun's 5778 K.
Properties
- absmag
- -12.99
- bv
- 1.197
- constellation
- Vul
- luminosity
- 13677288.256
- mag
- 7.01
- name
- HR 7458
- spect
- F8IV
- var amplitude
- 0.69
- var designation
- U
- var max
- 6.764
- var min
- 7.454
Nearby objects
How to see it
Look for HR 7458 in the constellation Vul. At apparent magnitude 7.01, it is an easy target for binoculars.
Like any astronomical target, HR 7458 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 HR 7458 is an uncommon variable star
HR 7458 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.