Merope (star)

{{short description|B-type subgiant star in the constellation Taurus}}

{{Starbox begin

| name=Merope

}}

{{Starbox image

| image =

{{Location mark

| image = Pleiades large.jpg | width = 280

| alt = Image of the Pleiades star cluster | float = center

| mark = Red circle.svg | mark_width = 30

| x = 585 | y = 515

}}

| caption = Merope in the Pleiades cluster (circled)

}}

{{Starbox observe

|epoch=J2000

| ra={{RA|03|46|19.5859}}

| dec={{DEC|+23|56|54.092}}

| appmag_v=4.18

| constell=Taurus

}}

{{Starbox character

| class= B6IV(e)

| b-v= −0.06

| u-b= −0.41

| variable= β Cephei

}}

{{Starbox astrometry

| radial_v = 6.2

| prop_mo_ra = 13.075

| prop_mo_dec = −48.404

| parallax = 7.0670

| p_error = 0.2862

| parallax_footnote=

| absmag_v = −1.29

}}

{{Starbox detail

| mass = 4.25

| radius = {{val|4.79|0.17}}

| luminosity = 927

| temperature = 14,550

| metal_fe =

| gravity = 3.48

| rotational_velocity = 240

| age_myr = 212{{cite journal | bibcode=2012AstL...38..771G | doi=10.1134/S1063773712120031 | arxiv=1606.08814 | title=Dependence of kinematics on the age of stars in the solar neighborhood | journal=Astronomy Letters | volume=38 | issue=12 | pages=771–782 | year=2012 | last1=Gontcharov | first1=G. A. | s2cid=118345778 }}

}}

{{Starbox catalog

|names=Merope, 23 Tau, V971 Tauri, HR 1156, BD+23°522, HD 23480, HIP 17608, SAO 76172, GC 4512, CCDM J03463+2357A

}}

{{Starbox reference

| Simbad=HD+23480

}}

Merope {{IPAc-en|'|m|Er|@|p|iː}}, designated 23 Tauri (abbreviated 23 Tau), is a star in the constellation of Taurus and a member of the Pleiades star cluster. It is approximately {{convert|135|pc|ly|order=flip|lk=on}} away.

Distance

File:Pleiades Spitzer big.jpg around Merope (Spitzer false colour infrared image)]]

Despite being one of the closest star clusters to Earth, the distance to the Pleiades and its member stars is still in dispute. The parallax of Merope itself is not known precisely enough to give an accurate distance. Its Hipparcos parallax has a statistical margin of error of about 5% and gave a distance 116 parsecs. This, and an overall distance to the Pleiades calculated from Hipparcos parallaxes of 120 parsecs, are inconsistent with other parallax measurements such as from Gaia. Merope is too bright for Gaia to have a reliable parallax for it, but calculations of the overall distance to the Pleiades cluster using Hipparcos, Gaia, Hubble Space Telescope, and other methods repeatedly show that the Hipparcos parallaxes suffered from some kind of systemic error, and the distance to the Pleiades is most likely around 135 parsecs.

Description

File:V971TauLightCurve.png for V971 Tauri (Merope), adapted from White et al. (2017)]]

Merope is a blue-white B-type subgiant with a mean apparent magnitude of +4.18. Richard Hinckley Allen described the star as lucid white and violet.Merope, Star Names and their Meanings, Richard Hinckley Allen, Dover Publications,

1963, p. 407. It has a luminosity of 927 times that of the Sun and a surface temperature of {{val|14,550|ul=K|fmt=commas}}. Merope's mass is roughly {{solar mass|4.25|link=y}} and has a radius 4.8 times as great as the Sun's.

Merope is classified as a Beta Cephei variable, a type of hot variable star which pulsates regularly due to opacity changes in its atmosphere. Its brightness varies by up to 0.01 magnitudes during each pulsation cycle. It is given the variable star designation of V971 Tauri. The period of variability is stable at 0.49 days, although the amplitude of the brightness changes on each cycle varies.

Some papers have reported a companion star to Merope, at a separation of {{val|250|ul=mas}}, as well as several other visual companions farther out. These possible companions have not been confirmed.

Surrounding Merope is the Merope Nebula (NGC 1435). It appears brightest around Merope and is listed in the Index Catalogue as number IC 349.

Nomenclature

23 Tauri is the star's Flamsteed designation. The name Merope originates with Greek mythology; she is one of the seven daughters of Atlas and Pleione known as the Pleiades. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Merope for this star. It is now so entered in the IAU Catalog of Star Names.

References

{{reflist|refs=

{{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN)|accessdate=22 May 2016}}

{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/WGSN_bulletin1.pdf | title=Bulletin of the IAU Working Group on Star Names, No. 1 |accessdate=28 July 2016}}

{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |accessdate=28 July 2016}}

{{cite journal |bibcode=2017A&A...598A..48G |title=A revised moving cluster distance to the Pleiades open cluster |last1=Galli |first1=P. A. B. |last2=Moraux |first2=E. |last3=Bouy |first3=H. |last4=Bouvier |first4=J. |last5=Olivares |first5=J. |last6=Teixeira |first6=R. |journal=Astronomy and Astrophysics |year=2017 |volume=598 |pages=A48 |doi=10.1051/0004-6361/201629239 |arxiv=1610.05641 |s2cid=119225372 }}

{{cite journal | title=Surveying the Bright Stars by Optical Interferometry. III. A Magnitude-limited Multiplicity Survey of Classical Be Stars | year=2021 | last1=Hutter | first1=D. J. | last2=Tycner | first2=C. | last3=Zavala | first3=R. T. | last4=Benson | first4=J. A. | last5=Hummel | first5=C. A. | last6=Zirm | first6=H. | journal=The Astrophysical Journal Supplement Series | volume=257 | issue=2 | page=69 | doi=10.3847/1538-4365/ac23cb | arxiv=2109.06839 | bibcode=2021ApJS..257...69H | s2cid=237503492 | doi-access=free }}

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{{cite journal | bibcode=1953GCRV..C......0W| title=General catalogue of stellar radial velocities| journal=Washington| last1=Wilson| first1=Ralph Elmer| year=1953}}

{{cite journal | last1=Crawford | first1=D. L. | last2=Barnes | first2=J. V. | last3=Golson | first3=J. C. | title=Four-color, Hbeta, and UBV photometry for bright B-type stars in the northern hemisphere | journal=The Astronomical Journal | date=1971 | page=1058 | volume=76 | bibcode=1971AJ.....76.1058C | doi=10.1086/111220 }}

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{{cite journal |last1=White |first1=T. R. |last2=Pope |first2=B. J. S. |last3=Antoci |first3=V. |last4=Papics |first4=P. I. |last5=Aerts |first5=C. |last6=Gies |first6=D. R. |last7=Gordon |first7=K. |last8=Huber |first8=D. |last9=Schaefer |first9=G. H. |last10=Aigrain |first10=S. |last11=Albrecht |first11=S. |last12=Barclay |first12=T. |last13=Barentsen |first13=G. |last14=Beck |first14=P. G. |last15=Bedding |first15=T. R. |last16=Fredslund |first16=M. |last17=Andersen |first17=M. Fredslund |last18=Grundahl |first18=F. |last19=Howell |first19=S. B. |last20=Ireland |first20=M. J. |last21=Murphy |first21=S. J. |last22=Nielsen |first22=M. B. |last23=Aguirre |first23=V. Silva |last24=Tuthill |first24=P. G. |title=Beyond the Kepler/K2 bright limit: variability in the seven brightest members of the Pleiades |journal=Monthly Notices of the Royal Astronomical Society |date=November 2017 |volume=471 |issue=3 |pages=2882–2901 |doi=10.1093/mnras/stx1050 |arxiv=1708.07462 |bibcode=2017MNRAS.471.2882W |doi-access=free }}

{{cite journal | bibcode=1982ApJS...50...55S| title=Spectral types and rotational velocities of the brighter Be stars and A-F type shell stars| journal=Astrophysical Journal Supplement Series| volume=50| pages=55| last1=Slettebak| first1=A| year=1982| doi=10.1086/190820| doi-access=free}}

{{cite journal

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| journal=Astronomy Letters

| volume=38 | issue=5 | pages=331 | year=2012

| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015

| arxiv=1108.4971 | s2cid=119257644 }}

{{cite journal |last1=Zorec |first1=J. |last2=Royer |first2=F. |title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities |journal=Astronomy and Astrophysics |date=January 2012 |volume=537 |pages=A120 |doi=10.1051/0004-6361/201117691 |arxiv=1201.2052 |issn=0004-6361 |bibcode=2012A&A...537A.120Z|s2cid=55586789 }}

{{cite journal

| title=Critical study of the distribution of rotational velocities of Be stars. I. Deconvolution methods, effects due to gravity darkening, macroturbulence, and binarity

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| volume=595 | date=November 2016 | pages=26

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{{cite journal

|display-authors=4

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|author2=Nelan E.

|author3=Benedict G. F.

|author4=McArthur B.

|author5=Ramirez I.

|author6=Spiesman W.

|author7=Jones B. F.

|date=2005

|title=Confirmation of Errors in Hipparcos Parallaxes from Hubble Space Telescope Fine Guidance Sensor Astrometry of the Pleiades

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|volume=129 |pages=1616–1624

|bibcode=2005AJ....129.1616S

|doi=10.1086/427860

|arxiv=astro-ph/0412093

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{{Cite journal

|display-authors= 4

|first1= Carl |last1= Melis

|first2= Mark J. |last2= Reid

|first3= Amy J. |last3= Mioduszewski

|first4= John R. |last4= Stauffer

|first5= Geoffrey |last5= Bower

|date= 29 August 2014

|title= A VLBI resolution of the Pleiades distance controversy

|journal= Science

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|pmid= 25170147 |arxiv = 1408.6544 |bibcode = 2014Sci...345.1029M |s2cid= 34750246 }}

{{ Cite journal

| author = Anthony G. A. Brown

| author2 = GAIA Collaboration

| date = 2016

| title = Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties

| type = forthcoming article

| journal = Astronomy and Astrophysics

| doi = 10.1051/0004-6361/201629512

| bibcode=2016A&A...595A...2G

| volume=595

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| arxiv = 1609.04172

| s2cid = 1828208

}}

{{cite journal |last1=Abramson |first1=Guillermo |title=The Distance to the Pleiades According to Gaia DR2 |journal=Research Notes of the AAS |date=20 August 2018 |volume=2 |issue=3 |pages=150 |doi=10.3847/2515-5172/aada8b|bibcode=2018RNAAS...2..150A |doi-access=free |hdl=11336/94435 |hdl-access=free }}

}}

External links

Jim Kaler's Stars, University of Illinois:[http://stars.astro.illinois.edu/sow/merope.html Merope (23 Tauri)]
[http://www.perseus.gr/Astro-DSO-NGC-1435.htm NGC 1435 - Merope Nebula] LRGB image with 4 hours total exposure.

Tauri, 023

Category:Taurus (constellation)

Category:Beta Cephei variables

Category:Pleiades

Category:B-type subgiants