When is the best time to observe Marfik?

Marfik is best observed from April through June, with peak visibility during May when it transits around midnight in the Northern Hemisphere.

Where is Marfik located in the sky?

Marfik lies in the constellation Ofiuco at right ascension 16h 31m and declination +01° 59′.

What telescope do I need to split Marfik?

Splitting Marfik requires an aperture of roughly 150 mm or larger — the components are separated by about 1.3″ at magnitudes near 3.8. Larger apertures and steady seeing help resolve the pair cleanly.

Marfik — Stella doppia in Ofiuco

Lambda Oph

Stella doppia osservabile Discreto (30/100)

Sep: 1.3", Companion: mag 5.2

Magnitudine 3.8^m DoubleStar Ofiuco (Oph) Visibile

Mappa stellare + Lista + Piano

Su Marfik

Descrizione

Marfik, Lambda Ophiuchi, is a binary star system about 173 light-years away in the constellation Ophiuchus. The primary is a B9/A0 III subgiant and the companion is an A-type dwarf at 1.5 arcseconds separation. Combined magnitude is 3.82. The orbital period is about 130 years, making Marfik a fine binary for long-term observation.

Consigli per l'osservazione

Marfik sits in the eastern part of Ophiuchus, near the boundary with Serpens Cauda. The 1.5-arcsecond double challenges small scopes — needs a 4-inch or larger at 200x on steady seeing nights. The two components are similar in brightness, providing a pleasing matched pair. Best observed May through September.

Storia

The name Marfik comes from the Arabic "al-mirfaq," meaning "the elbow" — referring to Ophiuchus's elbow in the traditional figure. The IAU adopted the name in 2017.

Curiosità

The Marfik binary has been observed since the 19th century, and its orbit is now well-determined through accumulated position measurements. Its 130-year period means that a single human lifetime can witness roughly two-thirds of a full revolution — a modest but real demonstration of gravitational orbital motion.

Osservare

1Proprietà fisiche

Magnitudine 3.82

Tipo spettrale B9/A0 III

Colore della stella Bianco-blu (B-V 0.01)

Distanza 173 ly

2Posizione e identificatori

RA 16h 30m 54.8s

Dec +01° 59' 02.0"

Costellazione Ofiuco (Oph)

HR 6149

HIP 80883

HD 148857

SAO 121658

Bayer Lambda

Flamsteed 10 Oph

Double Cat 10087

SIMBAD Wikipedia

3Facilità di separazione

Principale 3.8 mag Compagna 5.2 mag Separazione 1.3″

Accedi e configura la tua attrezzatura e località predefinita per vedere una riga personalizzata.

Telescopio	Bortle 3	Bortle 4	Bortle 5
Rifrattore 80 mm Rifr. 80mm	M. diff.+	M. diff.+	M. diff.+
Newton 150 mm Newt. 150mm	Diff.+	Diff.+	Diff.+
Celestron C8 (SCT 203 mm) C8 203mm	Medio	Medio	Medio

Facile Medio Difficile Molto difficile Impossibile

Bortle 3 = rurale · 4 = periferia · 5 = suburbano

4Visibilità

Imposta una località nelle impostazioni per vedere i dati di visibilità.

Periodo migliore Apr – Jun (peak: May)

5Sistema stellare multiplo Quadruple D: ottico

Componenti 4 (quadruple)

ID componenti AB

Separazione 1.3″

Mag compagna 5.2

Sp compagna A0V

Angolo di posizione 46°

Colori delle stelle A: Bianco-blu B: Bianco-blu

Scopritore STF2055

Note

AB 4.16 A1V, 5.22 A4V. 129.87y, a = 0.970" or 126.78y, a = 0.95", combined mag., colors. Component C, 11.0v, 120" CPM.

Separazione nel tempo

Periodo: 129.0 y Eccentricità: 0.615 Ora: 1.3", PA 51° -0.06" in 5 anni

Distanza apparente nel tempo, calcolata dagli elementi orbitali ORB6. Curve ripide indicano coppie in rapida evoluzione — osservatele finché sono separabili.