Epsilon Normae

{{Short description|Triple star system in the constellation Norma}}

{{Starbox begin

| name = Epsilon Normae

}}

{{Starbox observe 2s

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Norma

| component1 = A

| ra1 = {{RA|16|27|11.03611}}

| dec1 = {{DEC|−47|33|17.2226}}

| appmag_v1 = 4.47

| component2 = B

| ra2 = {{RA|16|27|10.06643}}

| dec2 = {{DEC|−47|32|56.6763}}

| appmag_v2 = 6.13

}}

{{Starbox character

| class = {{nowrap|B4 V + B4 V + B9 V}}

| b-v = −0.07

| u-b = −0.54

| variable =

}}

{{Starbox astrometry

| component1 = A

| radial_v = {{Val|−12.5|2.7}}

| prop_mo_ra = {{Val|−13.68|0.27}}

| prop_mo_dec = {{Val|−19.89|0.20}}

| parallax = 6.15

| p_error = 0.28

| parallax_footnote =

| absmag_v = +0.06

| component2 = B

| radial_v2 = {{Val|−6.67|0.83}}

| prop_mo_ra2 = −10.393

| prop_mo_dec2 = −20.277

| parallax2 = 5.4467

| p_error2 = 0.0299

| parallax_footnote2 =

| absmag_v2 =

}}

{{Starbox orbit

| reference =

| primary = Aa

| name = Ab

| period_unitless = 3.2617 d

| eccentricity = 0.13

| periastron = 2438825.9310 JD

| periarg = 271.5

| k1 = 122.5

| k2 = 132.9

}}

{{Starbox detail

| component1 = Aa

| mass = 7.7

| radius =

| luminosity =

| temperature =

| gravity =

| metal_fe =

| rotational_velocity =

| age_myr =

| component2 = Ab

| mass2 = 4.5

}}

{{Starbox detail |no_heading=y

| component1 = B

| mass = 2.3

| temperature = 11,104

| luminosity = 74

| radius = 2.4

| gravity = 4.00

| age_myr =

}}

{{Starbox catalog

| names = {{odlist | B=ε Nor | CD=−47°10765 | HD=147971 | HIP=80582 | HR=6115 | SAO=226773 | WDS=J16272-4733A }}

| component2 = B

| names2 = {{odlist | HD=147970 | HIP=80579 }}

}}

{{Starbox reference

| Simbad = eps+Nor

| Simbad2 = HD+147970 |sn2 = B

}}

{{Starbox end}}

Epsilon Normae, Latinised from ε Normae, is a blue-white hued triple star system in the southern constellation of Norma. It has an apparent visual magnitude of 4.47, which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 6.15 mas as seen from Earth, the system is located around 530 light years distant from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.21 due to interstellar dust.

The inner pair form a double-lined spectroscopic binary system with an orbital period of 3.26 days and an eccentricity of 0.13. Both stars appear to be similar B-type main-sequence stars with stellar classifications of B4 V.

The third component, at an angular separation of 22.8 arc seconds from the inner pair, is HD 147970. It is most likely is a smaller B-type main sequence star of spectral type B9V.

References

{{reflist|refs=

{{cite simbad | title=eps Nor | accessdate=2017-08-12 }}

{{cite simbad | title=HD 147970 | accessdate=2025-05-28 }}

{{cite Gaia DR3|5942012251017996928}}

{{cite journal |bibcode=2018ApJS..235....6T |title=The Updated Multiple Star Catalog |last1=Tokovinin |first1=Andrei |journal=The Astrophysical Journal Supplement Series |date=2018 |volume=235 |issue=1 |page=6 |doi=10.3847/1538-4365/aaa1a5 |doi-access=free |arxiv=1712.04750 }}

{{cite journal |bibcode=2000A&A...355L..27H |title=The Tycho-2 catalogue of the 2.5 million brightest stars |last1=Høg |first1=E. |last2=Fabricius |first2=C. |last3=Makarov |first3=V. V. |last4=Urban |first4=S. |last5=Corbin |first5=T. |last6=Wycoff |first6=G. |last7=Bastian |first7=U. |last8=Schwekendiek |first8=P. |last9=Wicenec |first9=A. |journal=Astronomy and Astrophysics |date=2000 |volume=355 }}

{{citation

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| journal=Astronomy and Astrophysics

| volume=474 | issue=2 | pages=653–664 | date=2007

| arxiv=0708.1752 | bibcode=2007A&A...474..653V

| doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}

{{citation

| title=Spatial distribution and kinematics of OB stars

| last1=Gontcharov | first1=G. A.

| journal=Astronomy Letters

| volume=38 | issue=11 | pages=694–706 | date=November 2012

| doi=10.1134/S1063773712110035 | bibcode=2012AstL...38..694G

| arxiv=1606.09028 | s2cid=119108982 | postscript=. }}

{{citation

| display-authors=1 | last1=Pourbaix | first1=D.

| last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H.

| last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I.

| last6=Levato | first6=H. | last7=Morrell | first7=N. I.

| last8=Torres | first8=G. | last9=Udry | first9=S.

| year=2004 | pages=727–732 | volume=424

| title=SB9: The Ninth Catalogue of Spectroscopic Binary Orbits

| journal=Astronomy & Astrophysics | bibcode=2004A&A...424..727P

| doi=10.1051/0004-6361:20041213 | postscript=. | arxiv=astro-ph/0406573| s2cid=119387088 }}

{{citation

| last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A.

| title=A catalogue of multiplicity among bright stellar systems

| journal=Monthly Notices of the Royal Astronomical Society

| volume=389 | issue=2 | pages=869–879 | date=September 2008

| bibcode=2008MNRAS.389..869E | doi=10.1111/j.1365-2966.2008.13596.x

| doi-access=free | arxiv=0806.2878 | s2cid=14878976 | postscript=. }}

{{citation

| title = A spectroscopic survey on the multiplicity of high-mass stars

| journal = Monthly Notices of the Royal Astronomical Society

| volume = 424 | issue = 3 | pages = 1925 | year = 2012

| display-authors=1 | last1 = Chini | first1 = R.

| last2 = Hoffmeister | first2 = V. H. | last3 = Nasseri | first3 = A.

| last4 = Stahl | first4 = O. | last5 = Zinnecker | first5 = H.

| bibcode = 2012MNRAS.424.1925C | doi = 10.1111/j.1365-2966.2012.21317.x

| doi-access = free

| arxiv = 1205.5238 | s2cid = 119120749

| postscript=. }}

{{citation

| last1=de Bruijne | first1=J. H. J. | last2=Eilers | first2=A.-C.

| title=Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project

| journal=Astronomy & Astrophysics

| volume=546 | id=A61 | pages=14 | date=October 2012

| doi=10.1051/0004-6361/201219219 | bibcode=2012A&A...546A..61D

| arxiv=1208.3048 | s2cid=59451347 | postscript=. }}

{{citation

| title=UBVRIJKL Photometry of the Bright Stars

| last1=Johnson | first1=H. L.

| journal=Communications of the Lunar and Planetary Laboratory

| volume=4 | date=1966 | page=99 | postscript=.

| bibcode=1966CoLPL...4...99J }}

}}

{{Stars of Norma|state=collapsed}}

{{DEFAULTSORT:Epsilon Normae}}

Category:B-type main-sequence stars

Category:Triple star systems

Category:Norma (constellation)

Normae, Epsilon

CD-47 10765

147971

080582

6115