Theta1 Crucis

{{Short description|Spectroscopic binary star system in the constellation Crux}}

{{Starbox begin

| name= θ¹ Crucis

}}

{{Starbox observe

| constell = Crux

| epoch = J2000.0 (ICRS)

| ra = {{RA|12|03|01.50130}}

| dec = {{DEC|−63|18|46.5406}}

| appmag_v = 4.30

}}

{{Starbox character

| class = A3(m)A8-A8

| b-v = +0.28

| u-b = +0.03

| variable =

}}

{{Starbox astrometry

| radial_v = −2.4

| prop_mo_ra = −152.35

| prop_mo_dec = +7.00

| parallax = 13.88

| p_error = 0.15

| parallax_footnote =

| absmag_v = +1.29

}}

{{Starbox orbit

| reference =

| period_unitless = 24.4828 d

| eccentricity = 0.61

| periastron = 2419453.3470 JD

| periarg = 358.9

| k1 = 46.1

| k2 = 56.1

}}

{{Starbox detail

| mass = 1.57

| radius =

| luminosity = 81

| temperature = {{Val|7341|250}}

| metal_fe =

| gravity = 3.76

| rotational_velocity =

| age_gyr = 1.1

}}

{{Starbox catalog

| names = θ¹ Cru, CPD−62°2543, HD 104671, HIP 58758, HR 4599, SAO 251705

}}

{{Starbox reference

| Simbad = tet01+Cru

}}

Theta¹ Crucis (θ¹ Cru, Theta¹ Crucis) is a spectroscopic binary star system in the southern constellation of Crux. It is visible to the naked eye with an apparent visual magnitude of 4.30^m. The distance to this star, as determined using parallax measurements, is around 235 light years.

The pair orbit each other closely with a period of 24.5 days and an eccentricity of 0.61. The primary component is an Am star, which is a chemically peculiar A-type star that shows anomalous variations in absorption lines of certain elements. It has a stellar classification of A3(m)A8-A8. With a mass 157% times that of the Sun, it radiates 81 times the Sun's luminosity from its outer atmosphere at an effective temperature of 7341 K. Unusually for a fully radiative A-type star, X-ray emissions have been detected, which may instead be coming from the orbiting companion.

References

{{reflist|refs=

{{citation

| title=Validation of the new Hipparcos reduction

| last1=van Leeuwen | first1=F.

| 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

| last=Wilson | first=Ralph Elmer | date=1953

| title=General Catalogue of Stellar Radial Velocities

| journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution of Washington

| location=Washington | bibcode=1953GCRV..C......0W

| postscript=. }}

{{citation

| title=S_B⁹: The ninth catalogue of spectroscopic binary orbits

| journal=Astronomy & Astrophysics

|display-authors=5 | 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.

| volume=424 | issue=2 | pages=727–732 | date=2004

| doi=10.1051/0004-6361:20041213 | bibcode=2004A&A...424..727P

| arxiv=astro-ph/0406573 | s2cid=119387088

| postscript=. }}

{{citation

| last1=Houk | first1=N. |last2=Cowley | first2=A. P.

| title=University of Michigan Catalogue of two-dimensional spectral types for the HD stars

| volume=1 | year=1975 | bibcode=1975mcts.book.....H

| postscript=. }}

{{citation

| last1=Renson | first1=P. | last2=Manfroid | first2=J.

| title=Catalogue of Ap, HgMn and Am stars

| journal=Astronomy and Astrophysics

| volume=498 | issue=3 | pages=961–966 |date=May 2009

| doi=10.1051/0004-6361/200810788 | bibcode=2009A&A...498..961R

| postscript=. | url=https://zenodo.org/record/890529| doi-access=free }}

{{citation

| last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A.

| title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets

| journal=The Astrophysical Journal

| volume=804 | issue=2 | pages=146 | year=2015

| bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146

| arxiv=1501.03154 | s2cid=33401607 | postscript=. }}

{{citation

| last1=Schröder | first1=C. | last2=Schmitt | first2=J. H. M. M.

| title=X-ray emission from A-type stars

| journal=Astronomy and Astrophysics

| volume=475 | issue=2 | pages=677–684 |date=November 2007

| doi=10.1051/0004-6361:20077429 | bibcode=2007A&A...475..677S

| postscript=. | doi-access=free }}

{{citation