Login
Login

iota Boötis

{{short description|Binary star system in the constellation of Boötes}}

{{Starbox begin

| name = ι Boötis

}}

{{Starbox image

| image=

{{Location mark

| image=Boötes IAU.svg

| alt= | float=center | width=300

| label= | position=right

| mark=Red circle.svg | mark_width=8 | mark_link=ι Boö

| x%=54.4 | y%=16.0

}}

| caption = Location of ι Boötis (circled)

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|14|16|09.930}}

| dec = {{DEC|+51|22|02.029}}

| appmag_v = 4.75 ({{val|4.73|-|4.78}})

| constell = Boötes

}}

{{Starbox character

| class = {{nowrap|A7 V + K0 V}}

| r-i = +0.09

| v-r =

| b-v = +0.20

| u-b = +0.06

| variable = Delta Scuti variable

}}

{{Starbox astrometry

| radial_v = −18.7

| prop_mo_ra = −149.277

| prop_mo_dec = +89.135

| pm_footnote =

| parallax = 33.8856

| p_error = 0.0820

| parallax_footnote =

| dost_pc = 29.1

| absmag_v = +2.38

}}

{{Starbox detail

| component1 = ι Boo A

| mass = 1.650{{±|0.04}}

| radius = 1.715{{±|0.055|0.021}}

| luminosity = 8.90{{±|0.06|0.07}}

| temperature = 7,764{{±|3|8}}

| metal_fe = +0.19

| gravity = 4.14{{±|0.01|0.02}}

| rotational_velocity = 144

| age_myr = 785{{±|223}}

| component2 = HD 234121

| mass2 = 0.807{{±|0.042|0.041}}

| radius2 = 0.824{{±|0.017}}

| luminosity2 = 0.411{{±|0.051|0.041}}

| temperature2= 5,090{{±|17|4}}

| gravity2 = 4.511{{±|0.018|0.005}}

}}

{{Starbox catalog

| names = {{odlist | name=Asellus Secondus | B=ι Boötis | F=21 Boötis | BD=+52°1784 | FK5=528 | HD=125161 | HIP=69713 | HR=5350 | SAO=29071 | Wo=9474 | WDS=J14162+5122 | GC=19269 | PPM=34432 }}

}}

{{Starbox reference

| Simbad = HD+125161

| ARICNS =

}}{{starbox sources|HIP|CCDM|HR}}

{{Starbox end}}

Image:Iota Boötis and HD 234121.jpg

Iota Boötis is a wide binary star system in the constellation Boötes, approximately 96 light-years from Earth. Its name is a Bayer designation that is Latinized from ι Boötis, and abbreviated Iota Boo or ι Boo. The brighter component has the traditional name Asellus Secundus, pronounced {{IPAc-en|ə|ˈ|s|ɛ|l|ə|s|_|s|ɪ|ˈ|k|ʌ|n|d|ə|s}}, which is Latin for "second donkey colt", and the Flamsteed designation 21 Boötis. It is faintly visible to the naked eye with a typical apparent visual magnitude of +4.75. Based on parallax measurements, it is located at a distance of {{convert|96|ly|pc|0|abbr=out|lk=on}} from the Earth. The star is drifting closer to the Sun with a radial velocity of −19 km/s.

The companion is HD 234121, a K-type main-sequence star at an angular distance of 38.6 arcseconds; easily separated with binoculars.

Components

File:IotaBooLightCurve.png light curve for Iota Boötis, adapted from Kiss (1995)]]

The primary component is a white hued A-type main-sequence star with a stellar classification of A7V. It is classified as a Delta Scuti-type variable star and its brightness varies from magnitude +4.73 to +4.78 with a stable period of 38 minutes. This star is 785 million years old and has a high rate of spin, showing a projected rotational velocity of 144 km/s. It has 1.8 times the mass of the Sun and 1.7 times the Sun's radius. Iota Boötis is radiating 8.8 times the luminosity of the Sun from its photosphere at an effective temperature of 7,764 K.

The common proper motion companion, HD 234121, is a magnitude 7.3 main-sequence star belonging to spectral class K0V. It has a projected separation from ι Boo of {{val|1100|fmt=commas|ul=AU}}. HD 234121 has a mass of {{solar mass|0.8|link=y}}, a luminosity of {{solar luminosity|0.4|link=y}}, a temperature of {{val|5,090|fmt=commas|ul=K}}, and a radius of {{solar radius|0.8|link=y}}.

The Washington Double Star Catalog lists a third component, a 14th-magnitude star at 90 arcseconds, but it is an unrelated background star.

Nomenclature

This star, along with the other Aselli (θ Boo and κ Boo) and λ Boo, were Aulād al Dhiʼbah (أولاد الضّباع - awlād al-ḍibā‘), "the Whelps of the Hyenas".{{fix|text=the transcription does not match the Arabic}}

In Chinese, {{lang|zh|天槍}} ({{lang|zh-Latn|Tiān Qiāng}}), meaning Celestial Spear, refers to an asterism consisting of ι Boötis, κ2 Boötis and θ Boötis. Consequently, the Chinese name for ι Boötis itself is {{lang|zh|天槍二}} ({{lang|zh-Latn|Tiān Qiāng èr}}, {{langx|en|the Second Star of Celestial Spear}}).

{{clear left}}

References

{{reflist|refs=

{{cite simbad | title=iot Boo | access-date=2025-05-27 | mode=cs2 | postscript=. }}

{{cite Gaia DR3|1511727333122255744}}

{{cite Gaia DR3|1511727371779512704}}

{{cite Gaia DR3|1511721427543987456}}

{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ama_b.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive|url=https://web.archive.org/web/20100811014924/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ama_b.htm |date=2010-08-11 }}, Hong Kong Space Museum. Accessed on line November 23, 2010.

{{in lang|zh}} 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, {{ISBN|978-986-7332-25-7}}.

{{cite web

| title=Star Name

| first=R. H. | last=Allen

| page=105 | year=1963 | publisher=Dover

| url=https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Bootes*.html

| access-date=2025-05-27 }}

{{cite journal

| last1=Kiss | first1=L. L. | bibcode=1995IBVS.4237....1K

| title=BV Photometry of the Delta Scuti Star iota Bootis

| journal=Information Bulletin on Variable Stars

| date=August 1995 | volume=4237| page=1 }}

{{cite journal

| last=Abt | first=H. A.

| title=Visual multiples. VII - MK classifications

| journal=Astrophysical Journal Supplement Series

| volume=45 | pages=437–456

| date=March 1981

| doi=10.1086/190719

| bibcode=1981ApJS...45..437A

}}

{{cite journal|bibcode=2001AJ....122.3466M|title=The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog|journal=The Astronomical Journal|volume=122|issue=6|pages=3466

| display-authors=1 |last1=Mason|first1=Brian D.|last2=Wycoff|first2=Gary L.|last3=Hartkopf|first3=William I.|last4=Douglass|first4=Geoffrey G.|last5=Worley|first5=Charles E.|year=2001|doi=10.1086/323920|doi-access=free}}

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

{{cite journal|bibcode=2001AJ....121.2159G|title=The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. II. Basic Parameters of Program Stars and the Role of Microturbulence|journal=The Astronomical Journal|volume=121|issue=4|pages=2159

| display-authors=1 |last1=Gray|first1=R. O.|last2=Graham|first2=P. W.|last3=Hoyt|first3=S. R.

|year=2001|doi=10.1086/319957|doi-access=}}

{{cite journal|bibcode=2014MNRAS.437.1216D|title=The VAST Survey - III. The multiplicity of A-type stars within 75 pc|journal=Monthly Notices of the Royal Astronomical Society|volume=437|issue=2|pages=1216

| display-authors=1 |last1=De Rosa|first1=R. J.|last2=Patience|first2=J.|last3=Wilson|first3=P. A.|last4=Schneider|first4=A.|last5=Wiktorowicz|first5=S. J.|last6=Vigan|first6=A.|last7=Marois|first7=C.|last8=Song|first8=I.|last9=MacIntosh|first9=B.|last10=Graham|first10=J. R.|last11=Doyon|first11=R.|last12=Bessell|first12=M. S.|last13=Thomas|first13=S.|last14=Lai|first14=O.

|year=2014|doi=10.1093/mnras/stt1932|doi-access=free |arxiv = 1311.7141 |s2cid=88503488}}

{{cite journal

|bibcode=1999IBVS.4698....1K|title=On the monoperiodicity of the suspected delta Scuti star Iota Bootis|journal=Information Bulletin on Variable Stars

|volume=4698|pages=1

| display-authors=1 |last1=Kiss|first1=L. L.|last2=Alfaro|first2=E. J.|last3=Bakos|first3=G.|last4=Csak|first4=B.|last5=Szatmary|first5=K.

|year=1999}}

{{cite journal|bibcode=1967IAUS...30...57E|title=The Revision of the General Catalogue of Radial Velocities|journal=Determination of Radial Velocities and Their Applications|volume=30|pages=57|last1=Evans|first1=D. S.|year=1967}}

{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|display-authors=etal|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}

{{cite journal|bibcode= 2002yCat.2237....0D |title= VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system |journal= CDS/ADC Collection of Electronic Catalogues |volume= 2237 |last= Ducati |first= J. R. |year= 2002 }}

{{cite journal | last1=Malagnini | first1=M. L. | last2=Morossi | first2=C. | title=Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars | journal=Astronomy and Astrophysics Supplement Series | volume=85 | issue=3 | pages=1015–1019 |date=November 1990 | bibcode=1990A&AS...85.1015M }}

{{cite book | last=Allen | first=R. H. | year=1963 | author-link=Richard Hinckley Allen | title=Star Names: Their Lore and Meaning | url=https://archive.org/details/starnamestheirlo00alle/page/105 | access-date=2010-12-12 | edition=Reprint | publisher=Dover Publications Inc | location=New York | isbn=((0-486-21079-0)) | page=[https://archive.org/details/starnamestheirlo00alle/page/105 105] | url-access=registration }}

}}

External links

  • [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?HR%205350 HR 5350]
  • [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?CCDM%20J14162%2b5122A CCDM J14162+5122]
  • [http://aladin.u-strasbg.fr/AladinPreview?-c=V*+iot+Boo&ident=V*+iot+Boo&submit=Aladin+previewer Image Iota Boötis]
  • [https://web.archive.org/web/20080926185552/http://www.purplehell.com/riddletools/stars.htm The Constellations and Named Stars]

{{Stars of Boötes}}

{{DEFAULTSORT:Iota Bootis}}

Category:A-type main-sequence stars

Category:K-type main-sequence stars

Category:Delta Scuti variables

Category:Binary stars

Category:Boötes

Bootis, Iota

5350

Category:Delta Scuti variables

BD+52 1784

Bootis, 21

125161

069713

Asellus Secundus