1 Delphini

{{Starbox begin

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{{Starbox image

|image =

{{Location mark

|mark=Red circle.svg|mark_width=10|mark_link=1 Del

|x=494|y=554

}}

|caption=Location of 1 Delphini (circled)

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{{Starbox observe 2s

| epoch = J2000

| component1 = A

| constell = Delphinus

| ra1 = {{RA|20|30|17.9623}}

| dec1 = {{DEC|+10|53|45.335}}

| appmag_v1 = 6.20{{±|0.01}}

| component2 = B

| ra2 = {{RA| 20|30|17.9505}}

| dec2 = {{DEC|+10|53|46.244}}

| appmag_v2 = 8.00{{±|0.01}}

}}

{{Starbox character

| class = A1:III shell

| b-v = −0.03

| u-b = −0.11

| variable =

}}

{{Starbox astrometry

| radial_v = −15.5 ± 2

| absmag_v = −0.69

}}

{{Starbox astrometry|no_heading=y

| component1 = A

| prop_mo_ra = +19.320

| prop_mo_dec = +4.645

| parallax = 4.6400

| p_error = 0.0616

| parallax_footnote =

| pm_footnote =

| component2 = B

| parallax2 = 4.1851

| p_error2 = 0.1421

| parallax_footnote2 =

| prop_mo_ra2 = +19.545

| prop_mo_dec2 = +4.710

}}

{{Starbox detail

| component1 = A

| mass = 3.1{{±|0.3}}

| gravity = 3.66{{±|0.77}}

| temperature = 10,651{{±|932|1156}}

| rotational_velocity = 217

| age_myr = 246

| metal_fe = 0.00

| component2 = B

| gravity2 = 4.14{{±|0.19|0.47}}

| rotational_velocity2 = 370

}}

{{Starbox catalogue

| names = {{odlist|F = 1 Delphini|BD = +10°4303|HD = 195325|HIP = 101160|HR = 7836|SAO = 106172|WDS = J20303+1054AB}}

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{{Starbox reference

| Simbad =1+Del

}}

1 Delphini (1 Del) is the Flamsteed designation for a close binary star in the equatorial constellation Delphinus. With a combined apparent magnitude of 6.08, it is barely visible to the naked eye, even under ideal conditions. Parallax measurements put the components at a distance 703 and 780 light years respectively. However, its approaching the Solar System with a radial velocity of {{val|15|ul=km/s}}.

1 Del consists of three components. The brightest of them has a magnitude of 6.1; a companion located around 0.9 arcseconds from the primary has an apparent magnitude of 8.1; and a third star, located much farther away at around 17 arcseconds from component A, is the faintest with a magnitude of around 14 and is an unrelated background object.

The entire system has a stellar classification of A1: III sh, indicating that it is a white giant + a shell star. However, there is some uncertainty about the temperature class. When resolved, the secondary has a class of B9. 1 Del A has 3 times the mass of the Sun and an effective temperature of 10,651 K, giving it a bluish white glow. It is estimated to be almost 250 million years old and has a solar metallicity. Both components spin rapidly, with projected rotational velocities of 217 and 370 km/s respectively. As for the peculiarities, the shell star is a primary component; the spectrum of the secondary shows broad absorption lines.

Due to the stability of the emission lines data from 1 Delphini has been used for developing models of shell stars and Be stars.

References

{{reflist||refs=

{{cite journal |last1=Fabricius |first1=C. |last2=Høg |first2=E. |last3=Makarov |first3=V. V. |last4=Mason |first4=B. D. |last5=Wycoff |first5=G. L. |last6=Urban |first6=S. E. |title=The Tycho double star catalogue |journal=Astronomy & Astrophysics |date=March 2002 |volume=384 |issue=1 |pages=180–189 |doi=10.1051/0004-6361:20011822 |issn=0004-6361 |bibcode=2002A&A...384..180F |doi-access=free}}

{{cite journal |author=Ralph Elmer Wilson |date=1953 |title=General Catalogue of Stellar Radial Velocities |journal=Carnegie Institute Washington D.C. Publication |publisher=Carnegie Institution of Washington |bibcode=1953GCRV..C......0W |lccn=54001336}}

{{cite journal |bibcode=2016A&A...587A..22K |title=Spectroscopy of close visual binary components of the stable shell star 1 Delphini |last1=Kubát |first1=Jiří |last2=Kubátová |first2=Brankica |last3=Doležalová |first3=Barbora |last4=Iliev |first4=Lubomir |last5=Šlechta |first5=Miroslav |journal=Astronomy and Astrophysics |year=2016 |volume=587 |pages=A22 |doi=10.1051/0004-6361/201526414 |arxiv=1601.05236 |s2cid=118706088 }}

{{cite journal |last1=Anderson |first1=E. |last2=Francis |first2=Ch. |title=XHIP: An extended hipparcos compilation |journal=Astronomy Letters |date=May 2012 |volume=38 |issue=5 |pages=331–346 |doi=10.1134/S1063773712050015 |language=en |issn=1063-7737 |bibcode=2012AstL...38..331A |arxiv=1108.4971|s2cid=255204555 }}

{{cite journal |last1=Abt |first1=Helmut A. |last2=Morrell |first2=Nidia I. |title=The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars |journal=The Astrophysical Journal Supplement Series |date=July 1995 |volume=99 |pages=135 |doi=10.1086/192182 |issn=0067-0049 |bibcode=1995ApJS...99..135A |doi-access=free}}

{{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|author1=Ducati, J. R.|year=2002}}

{{cite journal |last1=Gontcharov |first1=G. A. |title=Dependence of kinematics on the age of stars in the solar neighborhood |journal=Astronomy Letters |date=December 2012 |volume=38 |issue=12 |pages=771–782 |doi=10.1134/S1063773712120031 |issn=0320-0108 |bibcode=2012AstL...38..771G |arxiv=1606.08814|s2cid=255201789 }}

{{cite journal |display-authors=1 |last1=Anders |first1=F. |last2=Khalatyan |first2=A. |last3=Queiroz |first3=A. B. A. |last4=Chiappini |first4=C. |last5=Ardèvol |first5=J. |last6=Casamiquela |first6=L. |last7=Figueras |first7=F. |last8=Jiménez-Arranz |first8=Ó. |last9=Jordi |first9=C. |last10=Monguió |first10=M. |last11=Romero-Gómez |first11=M. |last12=Altamirano |first12=D. |last13=Antoja |first13=T. |last14=Assaad |first14=R. |last15=Cantat-Gaudin |first15=T. |last16=Castro-Ginard |first16=A. |last17=Enke |first17=H. |last18=Girardi |first18=L. |last19=Guiglion |first19=G. |last20=Khan |first20=S. |last21=Luri |first21=X. |last22=Miglio |first22=A. |last23=Minchev |first23=I. |last24=Ramos |first24=P. |last25=Santiago |first25=B. X. |last26=Steinmetz |first26=M. |title=Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5 |journal=Astronomy & Astrophysics |date=February 2022 |volume=658 |pages=A91 |doi=10.1051/0004-6361/202142369 |issn=0004-6361 |bibcode=2022A&A...658A..91A |doi-access=free |arxiv=2111.01860 }}

}}

1 Delphini

References

Further reading