Iota1 Normae

Iota1 Normae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Norma
Right ascension 16h 03m 32.08942s[1]
Declination −57° 46′ 30.2641″[1]
Apparent magnitude (V) 4.69 (5.20 + 5.76 + 8.1)[2]
Characteristics
Spectral type A7 IV[3] (A4 V + A6 V)[4]
Astrometry
Radial velocity (Rv)−14.4±3.7[5] km/s
Proper motion (μ) RA: −120.01[1] mas/yr
Dec.: −82.09[1] mas/yr
Parallax (π)25.39 ± 1.25 mas[1]
Distance128 ± 6 ly
(39 ± 2 pc)
Orbit[6]
Period (P)26.84±0.09 yr
Semi-major axis (a)0.328±0.006
Eccentricity (e)0.515±0.012
Inclination (i)168.7±9.9°
Longitude of the node (Ω)42.0±43.2°
Periastron epoch (T)1990.87±0.21
Argument of periastron (ω)
(secondary)
320.0±44.1°
Details
ι1 Nor A
Mass1.94[7] M
Surface gravity (log g)4.25[8] cgs
Temperature7,842±267[8] K
Age731[8] Myr
ι1 Nor B
Mass1.65[7] M
Other designations
ι1 Nor, CPD−57° 7500, HD 143474, HIP 78662, HR 5961, SAO 243279, WDS J16035-5747AB[9]
Database references
SIMBADdata

Iota1 Normae (ι1 Normae) is a triple star[2] system in the southern constellation of Norma. With a combined apparent visual magnitude of 4.69,[2] it is faintly visible to the naked eye. Based upon an annual parallax shift of 25.39 mas as seen from Earth,[1] this system is located about 128 light years from the Sun. At that distance, the visual magnitude of these stars is diminished by an extinction factor of 0.062 due to interstellar dust.[3]

The inner pair orbit each other with a period of 26.8 years, a semimajor axis of 0.33 arc seconds, and an eccentricity of 0.515. They have a blended stellar classification of A7 IV,[3] matching a white-hued A-type subgiant star. Both stars are actual A-type main sequence stars. The brighter of the pair, magnitude 5.20[2] component A, has a spectral class of A4 V,[4] while its magnitude 5.76[2] companion, component B, is of class A6 V.[4] The two are 1.94 and 1.65 times as massive as the Sun, respectively.[3] The tertiary member, component C, is a magnitude 8.1[2] star with 0.88 times the mass of the Sun.[7] It lies at an angular separation of 10.8 arc seconds from the other members.

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Malkov2012 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Edwards1976 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Tokovinin2015 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Tokovinin2008 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference David2015 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).