Theta Apodis

{{Short description|Star in the constellation Apus}}

{{Starbox begin

| name = θ Apodis

}}

{{Starbox image

| image=

{{Location mark

|image=Apus constellation map.svg|alt=|float=center|width=240

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=θ Apodis

|x=728|y=624

}}

|caption=Location of θ Apodis (circled)

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|14|05|19.881}}

| dec = {{DEC|-76|47|48.34}}

| appmag_v = 4.65 - 6.20

| constell = Apus

}}

{{Starbox character

| class = M7 III

| b-v = +1.48

| u-b = +1.07

| variable = SRb

}}

{{Starbox astrometry

| radial_v = +9.0

| prop_mo_ra = −88.586

| prop_mo_dec = −32.655

| pm_footnote =

| parallax = 8.3808

| p_error = 0.3574

| parallax_footnote =

| absmag_v = 0.7

}}

{{Starbox detail

| mass = {{val|1.0|0.3}}

| radius = 208

| luminosity = {{val|3050|460|fmt=commas}}

| temperature = {{val|2850|160|fmt=commas}}

| metal_fe = −0.20

| gravity = +0.0

| rotational_velocity =

| age_gyr =

}}

{{Starbox catalog

| names = {{odlist | B=θ Apodis, Theta Aps | CD=-76°615 | FK5=1363 | HD=122250 | HIP=68815 | HR=5261 | SAO=257112 | AAVSO=1355-76 }}

}}

{{Starbox reference

|Simbad=tet+Aps

}}

{{Starbox end}}

Theta Apodis is a variable star in the southern circumpolar constellation of Apus. Its identifier is a Bayer designation that is Latinized from θ Apodis, and abbreviated Tet Aps or θ Aps, respectively. This is a variable star with an apparent visual magnitude range of 4.65 to 6.20, which, according to the Bortle Dark-Sky Scale, means it is a faint star but visible to the naked eye from dark suburban skies. The distance to Theta Apodis is approximately {{Convert|390|ly|pc|abbr=off|lk=on}}, based upon parallax measurements made from the Gaia telescope. It is unusual in that it is a red star with a high proper motion (greater than 50 milliarcseconds a year).

File:ThetaApsLightCurve.png for Theta Apodis, adapted from Moon et al. (2008)]]

Benjamin Apthorp Gould announced that Theta Apodis is a variable star, in 1879.

It is a semiregular pulsating variable and its brightness changes over a range of 0.56 magnitudes with a period of 119 days. A longer period of around 1,000 days has also been detected.

This is an evolved red giant that is currently on the asymptotic giant branch, with a stellar classification of M7 III. It shines with a luminosity approximately 3879 times that of the Sun and has a surface temperature of {{val|3131|ul=K|fmt=commas}}. It is losing mass at the rate of {{nowrap|1.1 × 10−7}} times the mass of the Sun per year through its stellar wind. Dusty material ejected from this star is interacting with the surrounding interstellar medium, forming a bow shock as the star moves through the galaxy. The stand-off distance for this front is located at about {{Convert|0.134|ly|pc|abbr=on|sigfig=2}} from Theta Apodis.

Theta Apodis has been identified as an astrometric binary, indicating that it has an orbiting companion that causes gravitational perturbation of the primary star.

References

{{reflist|30em|refs=

{{cite Gaia DR3|5786929090848333568}}

{{citation|last1=Gould |first1=Benjamin Apthorp |title=Uranometria Argentina: Brightness and position of every fixed star, down to the seventh magnitude, within one hundred degrees of the South Pole; with atlas |journal=Resultados del Observatorio Nacional Argentino |date=1879 |volume=1 |pages=I-387 |bibcode=1879RNAO....1....1G |url=https://articles.adsabs.harvard.edu/pdf/1879RNAO....1D...1G |access-date=19 December 2024}}

{{citation |bibcode=2017MNRAS.471..770M |title=Fundamental parameters and infrared excesses of Tycho-Gaia stars |journal=Monthly Notices of the Royal Astronomical Society |volume=471 |issue=1 |pages=770 | display-authors=1 |last1=McDonald |first1=I. |last2=Zijlstra |first2=A. A. |last3=Watson |first3=R. A. |year=2017 |arxiv=1706.02208 |doi=10.1093/mnras/stx1433 |doi-access=free |s2cid=73594365 |postscript=. }}

{{citation | postscript=. | url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=844 | title=VSX | accessdate=2018-10-29 | website=AAVSO.org }}

{{citation|bibcode=2019A&A...628A..94A |title=Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18 | display-authors=1 |last1=Anders |first1=F. |last2=Khalatyan |first2=A. |last3=Chiappini |first3=C. |last4=Queiroz |first4=A. B. |last5=Santiago |first5=B. X. |last6=Jordi |first6=C. |last7=Girardi |first7=L. |last8=Brown |first8=A. G. A. |last9=Matijevič |first9=G. |last10=Monari |first10=G. |last11=Cantat-Gaudin |first11=T. |last12=Weiler |first12=M. |last13=Khan |first13=S. |last14=Miglio |first14=A. |last15=Carrillo |first15=I. |last16=Romero-Gómez |first16=M. |last17=Minchev |first17=I. |last18=De Jong |first18=R. S. |last19=Antoja |first19=T. |last20=Ramos |first20=P. |last21=Steinmetz |first21=M. |last22=Enke |first22=H. |journal=Astronomy and Astrophysics |year=2019 |volume=628 |pages=A94 |doi=10.1051/0004-6361/201935765 |arxiv=1904.11302 |s2cid=131780028 }}

{{citation | display-authors=1 | last1=Jiménez-Esteban | first1=F. M. | last2=Caballero | first2=J. A. | last3=Dorda | first3=R. | last4=Miles-Páez | first4=P. A. | last5=Solano | first5=E. |date=2012|title=Identification of red high proper-motion objects in Tycho-2 and 2MASS catalogues using Virtual Observatory tools|journal=Astronomy & Astrophysics|volume=539|pages=12|doi=10.1051/0004-6361/201118375 |bibcode=2012A&A...539A..86J|arxiv = 1201.5315 |s2cid=53404166 }}

{{citation | display-authors=1 | last1=Yeşilyaprak | first1=C. | last2=Aslan | first2=Z. | title=Period-luminosity relation for M-type semiregular variables from Hipparcos parallaxes | journal=Monthly Notices of the Royal Astronomical Society | volume=355 | issue=2 | pages=601–607 |date=December 2004 | doi=10.1111/j.1365-2966.2004.08344.x | bibcode=2004MNRAS.355..601Y | postscript=. | doi-access=free }}

{{citation | display-authors=1 | last1=Feast | first1=M. W. | last2=Woolley | first2=R. | last3=Yilmaz | first3=N. | title=The kinematics of semi-regular red variables in the solar neighbourhood | journal=Monthly Notices of the Royal Astronomical Society | volume=158 | pages=23–46 | date=1972 | bibcode=1972MNRAS.158...23F | postscript=. | doi = 10.1093/mnras/158.1.23 | doi-access=free }}

{{citation | last1=Wisse | first1=P. N. J. | title=Three colour observations of southern red variable giant stars | journal=Astronomy and Astrophysics Supplement Series | volume=44 |date=May 1981 | pages=273–303 | bibcode=1981A&AS...44..273W | postscript=. }}

{{citation | title=tet Aps -- Semi-regular pulsating Star | work=SIMBAD | publisher=Centre de Données astronomiques de Strasbourg | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+122250 | accessdate=2012-07-08 | postscript=. }}

{{citation | display-authors=1 | last1=Cox | first1=N. L. J. | last2=Kerschbaum | first2=F. | last3=van Marle | first3=A.-J. | last4=Decin | first4=L. | last5=Ladjal | first5=D. | last6=Mayer | first6=A. | last7=Groenewegen | first7=M. A. T. | last8=van Eck | first8=S. | last9=Royer | first9=P. | last10=Ottensamer | first10=R. | last11=Ueta | first11=T. | last12=Jorissen | first12=A. | last13=Mecina | first13=M. | last14=Meliani | first14=Z. | last15=Luntzer | first15=A. | last16=Blommaert | first16=J. A. D. L. | last17=Posch | first17=Th. | last18=Vandenbussche, B. | last19=Waelkens, C. | title=A far-infrared survey of bow shocks and detached shells around AGB stars and red supergiants | journal=Astronomy & Astrophysics | volume=537 | page=A35 |date=January 2012 | doi=10.1051/0004-6361/201117910 | bibcode=2012A&A...537A..35C | postscript=. |arxiv = 1110.5486 | s2cid=56041336 }} See table 1, IRAS 14003-7633.

{{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 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E |arxiv = 0806.2878 | s2cid=14878976 }}

{{citation |last1=Ohnaka | first1=K. | title=High spectral resolution spectroscopy of the SiO fundamental lines in red giants and red supergiants with VLT/VISIR | journal=Astronomy and Astrophysics | volume=561 | date=January 2014 | bibcode=2014A&A...561A..47O |url=https://www.aanda.org/articles/aa/pdf/2014/01/aa21581-13.pdf|arxiv = 1310.7972 |doi = 10.1051/0004-6361/201321581 }}

{{citation|bibcode=2008JAVSO..36...77M|title=Combining Visual and Photoelectric Observations of Semiregular Red Variables|journal=Journal of the American Association of Variable Star Observers|volume=36|issue=1|pages=77|last1=Moon|first1=T. T.|year=2008|arxiv=0711.4873}}

}}

{{Stars of Apus}}

{{DEFAULTSORT:Theta Apodis}}

Category:M-type giants

Category:Semiregular variable stars

Category:Asymptotic-giant-branch stars

Category:Astrometric binaries

Category:Apus

Apodis, Theta

5261

Category:Durchmusterung objects

122250

068815

Apodis, 04