Su Matar
Descrizione
Matar, Eta Pegasi, is a bright-giant binary system about 215 light-years away in the constellation Pegasus. The primary is a G-type bright giant (G2 II-III) roughly 5 times the Sun's mass and 175 times its luminosity, accompanied by a closer F-type companion in a 813-day orbit. Matar marks one of the corners of the fainter Pegasus "neck," north of the Great Square. It shines at magnitude 2.94 and has a soft yellow-white color in binoculars.
Consigli per l'osservazione
Matar is an easy naked-eye target in moderately dark skies, forming the northwestern corner of a prominent asterism above the Great Square of Pegasus. Use the line from Scheat (Beta Peg) northward toward Polaris; Matar sits roughly one-third of the way along. The stellar companion is far too close (tens of milliarcseconds) to split visually in any amateur telescope — Matar is effectively a single point of warm yellow light at the eyepiece. Best observed August through December when Pegasus dominates the evening sky.
Storia
The name Matar derives from the Arabic "al-Sa'd al-Matar," meaning "the lucky star of rain," an allusion to its heliacal rising at the start of the rainy season on the Arabian peninsula. The International Astronomical Union formally adopted the name in 2016 as part of the Working Group on Star Names standardization effort. Along with Scheat, Markab, and Algenib, Matar has been used for centuries as a celestial marker of Pegasus.
Curiosità
Matar's G-type primary is one of the few bright giants close enough to have its angular diameter directly measured, yielding a radius of about 11 solar radii. The binary system radiates more than 250 times the Sun's total luminosity when both stars are combined. Matar's stellar wind is shedding mass at a rate roughly a million times higher than the Sun's — a preview of the star's future as it evolves toward its red-giant phase.
Osservare
1Proprietà fisiche
2Posizione e identificatori
3Facilità di osservazione
| Attrezzatura | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Occhio nudo Occhio nudo | Facile | Facile | Facile |
| Cercatore 50 mm Cercatore 50mm | Facile | Facile | Facile |
| Telescopio 150 mm 150mm telesc. | Facile | Facile | Facile |
Bortle 3 = rurale · 4 = periferia · 5 = suburbano
4Visibilità
Imposta una località nelle impostazioni per vedere i dati di visibilità.
Esplorare
6
Confronto dimensioni
7
Confronta stelle
8
Classificazione spettrale
9
Diagramma Hertzsprung-Russell
10
Ciclo di vita stellare
11
Spettro del corpo nero
12
Spettro di assorbimento stellare
Spettro di assorbimento simulato basato sul tipo spettrale. Passa il mouse sulle righe per identificare gli elementi.
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Fusione Stellare
Scoprire
14Note stellari
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Macchina del tempo della luce
16
Viaggio Relativistico
Immagine survey
Caricamento immagine survey…
Vicini nel cielo
Altri bersagli a pochi gradi — sposta un po’ il telescopio e continua a esplorare.
I punteggi di visibilità assumono un Newton da 150 mm con Bortle 4.
Esplora Nightbase
Conoscenze, strumenti e storie correlate — senza pianificare osservazioni.
