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{{Starbox begin
| name = HD 21071
}}{{Starbox observe
| epoch = J2000
| constell = Perseus
| ra = {{RA|03|25|57.38167}}[1]
| dec = {{DEC|+49|07|14.7332}}[1]
| appmag_v = 6.09[3]
}}{{Starbox character
| type =
| class = B7 V[4]
| b-v = {{Val|−0.073|0.005}}[3]
| u-b =
| variable = SPB[6]
}}{{Starbox astrometry
| radial_v = {{Val|−1.5|0.9}}[7]
| prop_mo_ra = +24.008[1]
| prop_mo_dec = −26.870[1]
| parallax = 6.0326
| p_error = 0.0660
| parallax_footnote = [1]
| absmag_v = −0.19[3]
}}{{Starbox detail
| source =
| mass = {{Val|3.69|0.14|0.15}}[6]
| radius = 2.21[13]
| luminosity = {{Val|278.0|53.1|44.7}}[6]
| temperature = 14,768[4]
| metal_fe = {{Val|0.0082|0.0053|0.0032}}[6]
| gravity = 4.30[4]
| rotational_velocity = 58[4]
| age_myr = 90[4]
}}{{Starbox catalog
| names = {{odlist | V=V576 Per | BD=+48° 913 | HD=21071 | HIP=15988 | HR=1029 | SAO=38817 | GC=4075 }}
}}{{Starbox reference
| Simbad = HD+21071
}}{{Starbox end}}HD 21071 is a blue-white hued variable star in the northern constellation of Perseus. It is a sixth magnitude star that is dimly visible to the naked eye under good viewing conditions, having an apparent visual magnitude of 6.09.[3] The brightness of the star varies with a multiperiodic cycle.[22] The distance to HD 21071, as determined from an annual parallax shift of {{Val|6.03|ul=mas}},[1] is 541 light years. It is a member of the young Alpha Persei cluster, Melotte 20,[4][25] and moving is closer to the Earth with a heliocentric radial velocity of −1.5 km/s.[7]This is a B-type main-sequence star with a stellar classification of B7 V.[4] HD 21071 belongs to an unusual stellar population termed 'sn' stars. These seem to be related to chemically peculiar stars, but have sharp ('s') Balmer and metal absorption lines with "broad coreless He I" ('n') lines. The latter wide, "nebulous" lines may be due to Stark broadening caused by an electric field.[4] HD 21071 is a slowly pulsating B-type star (SPB star) that was initially found to vary with a period of 0.84 days. Further study revealed four frequencies, with the two dominant, higher amplitude frequencies having similar cycles of 1.19 and 1.15 per day.[6] Pulsation Periods[6]| ID | Frequency
(d−1) | V Amplitude
(mmag) | Radial Velocity
(km/s) | | 1 | 1.18843 | 18.5 | 3.28|0.85}} | | 2 | 1.14934 | 7.7 | – | | 3 | 1.41968 | 3.8 | – | | 4 | 0.95706 | 3.0 | – | Stellar models show the star to have 3.7[6] times the mass of the Sun, with 2.21[13] times the Sun's radius. It is 90[4] million years old with a near-solar metallicity and is spinning with a projected rotational velocity of 58 km/s.[4] The star is radiating 278[6] times the Sun's luminosity from its photosphere at an effective temperature of 14,768 K.[4]References1. ^1 2 3 4 5 6 {{cite DR2}}
2. ^1 2 3 4 {{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | postscript=. }}
3. ^1 2 3 4 5 6 7 8 {{citation | title=Seismic modelling of the rotating, slowly pulsating B-type star HD 21071 | last1=Szewczuk | first1=W. | last2=Daszyńska-Daszkiewicz | first2=J. | journal=Monthly Notices of the Royal Astronomical Society | volume=453 | issue=1 | pages=277–286 | date=October 2015 | doi=10.1093/mnras/stv1589 | arxiv=1507.03609 | bibcode=2015MNRAS.453..277S | postscript=. }}
4. ^1 2 3 4 5 6 7 8 9 10 11 {{citation | title=On the nature of sn stars. I. A detailed abundance study | last1=Saffe | first1=C. | last2=Levato | first2=H. | journal=Astronomy & Astrophysics | volume=562 | id=A128 | pages=17 | date=February 2014 | bibcode=2014A&A...562A.128S | arxiv=1401.5764 | doi=10.1051/0004-6361/201322091 | postscript=. }}
5. ^1 {{citation | title=Stellar Membership and Dusty Debris Disks in the α Persei Cluster | last1=Zuckerman | first1=B. | last2=Melis | first2=Carl | last3=Rhee | first3=Joseph H. | last4=Schneider | first4=Adam | last5=Song | first5=Inseok | display-authors=1 | journal=The Astrophysical Journal | volume=752 | issue=1 | id=58 | pages=12 | date=June 2012 | doi=10.1088/0004-637X/752/1/58 | bibcode=2012ApJ...752...58Z | arxiv=1204.3950 | postscript=. }}
6. ^1 2 {{citation | title=Spectroscopic monitoring of 10 new northern slowly pulsating B star candidates discovered from the HIPPARCOS mission | last1=Mathias | first1=P. | last2=Aerts | first2=C. | last3=Briquet | first3=M. | last4=De Cat | first4=P. | last5=Cuypers | first5=J. | last6=Van Winckel | first6=H. | last7=Le Contel | first7=J. M. | display-authors=1 | journal=Astronomy and Astrophysics | postscript=. | volume=379 | pages=905–916 | date=December 2001 | doi=10.1051/0004-6361:20011406 | bibcode=2001A&A...379..905M }}
7. ^1 2 {{citation | last1=Gontcharov | first1=G. A. | title=Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system | journal=Astronomy Letters | volume=32| issue=11| pages=759–771| date=November 2006 | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G | arxiv=1606.08053 | postscript=. }}
8. ^1 {{citation | last1=Samus | first1=N. N. | last2=Kazarovets | first2=E. V. | last3=Durlevich | first3=O. V. | last4=Kireeva | first4=N. N. | last5=Pastukhova | first5=E. N. | display-authors=1 | title=General Catalogue of Variable Stars | version=GCVS 5.1 | journal=Astronomy Reports | year=2017 | volume=61 | issue=1 | pages=80–88 | bibcode=2017ARep...61...80S | postscript=. }}
}}{{Stars of Perseus}} 6 : B-type main-sequence stars|Perseus (constellation)|Durchmusterung objects|Henry Draper Catalogue objects|Hipparcos objects|HR objects |