When is the best time to observe Ain?

Ain is best observed from October through December, with peak visibility during November when it transits around midnight in the Northern Hemisphere.

Where is Ain located in the sky?

Ain lies in the constellation Touro at right ascension 04h 29m and declination +19° 11′.

What telescope do I need to split Ain?

Splitting Ain requires an aperture of roughly 60 mm or larger — the components are separated by about 190.4″ at magnitudes near 3.5. The companion is about 7.1 magnitudes fainter, so glare from the primary — not separation — sets the minimum aperture. Larger apertures and steady seeing help resolve the pair cleanly.

Ain — Estrela Dupla em Touro

HIP 20889; Epsilon Tauri; 74 Tauri

Magnitude 3.5^m DoubleStar Touro (Tau) Visível 1 Exoplanet

Mapa Estelar + Lista + Plano

Sobre Ain

Descrição

Ain, Epsilon Tauri, is a K-giant of spectral class G9.5 III about 147 light-years away. It is a member of the Hyades open cluster and became famous in 2007 as the first Hyades star confirmed to host an exoplanet — Ain b, a super-Jupiter of at least 7.6 Jupiter masses in a 1.6-year orbit. Ain's magnitude is 3.53 and its color is a warm pale orange.

Dicas de Observação

Ain marks the northern eye of the Taurus bull, above the V of the Hyades. In any small binoculars it appears as a warm yellow-orange point surrounded by dozens of fainter Hyades members. Ain is one of the "bull's eyes," with Aldebaran marking the southern eye. Best observed November through March.

História

The name Ain is Arabic for "eye," specifically designating the bull's northern eye. The pairing of Aldebaran ("the follower") and Ain ("the eye") in Taurus dates to pre-Islamic Arabic astronomy. The IAU adopted both names in 2016.

Curiosidades

Ain's planet was the first exoplanet discovered around a Hyades member — a milestone because the Hyades is the closest well-studied open cluster, allowing direct comparison of planetary-system outcomes in a co-evolving population of stars. The 625-million-year-old age of the Hyades means Ain b is a "young Jupiter," useful for studying how giant planets evolve over cosmic time.

Observar

1Propriedades Físicas

Magnitude 3.53

Tipo Espectral G9.5III CN0.5 gigante

Cor da Estrela Laranja (B-V 1.01)

Distância 147 ly

2Posição e Identificadores

RA 04h 28m 37.0s

Dec +19° 10' 49.0"

Constelação Touro (Tau)

HR 1409

HIP 20889

HD 28305

SAO 93954

Bayer Epsilon

Flamsteed 74 Tau

SIMBAD Wikipedia

3Facilidade de separação

Principal 3.5 mag Companheira 10.6 mag Separação 190.4″

Entrar e configure seu equipamento e local padrão para ver uma linha personalizada.

Telescópio	Bortle 3	Bortle 4	Bortle 5
Refrator 80 mm Refr. 80mm	Médio	Difícil+	Difícil
Newton 150 mm Newt. 150mm	Fácil	Médio+	Médio
Celestron C8 (SCT 203 mm) C8 203mm	Fácil	Fácil	Médio+

Fácil Médio Difícil Muito difícil Impossível

Bortle 3 = rural · 4 = suburbano · 5 = urbano

4Visibilidade

Defina um local nas Configurações do Usuário para ver dados de visibilidade.

Melhor temporada Oct – Dec (peak: Nov)

5Sistema Estelar Múltiplo

Separação 190.4″

Mag da Companheira 10.6

Ângulo de Posição 269°

Cores das Estrelas A: Laranja

Descobridor BUP 61

Separação ao longo do tempo

Medido 1894 → 2015 (121 y)

Deriva de separação 179.9" → 190.4" (+10.50")

Taxa +0.0868" / y

Deriva do AP 268° → 269° (+1°, +0.008°/y)

Movimento aparente significativo à escala humana — vale a pena rever daqui a uma década.

Medido a partir do arquivo observacional WDS. Nenhuma solução orbital foi derivada — provavelmente o período é demasiado longo para ajustar uma órbita ao arco de medições disponível.