“HN Andromedae”的意思、由来-开放百科全书

The HN Andromedae system is triple, as seen in periodic radial velocity variations. The primary component is a star that is leaving the main sequence with an absolute magnitude M_v={{val|-0.03|0.42}}, dominates the observed spectrum^[16] and its spectral classification is A2pSrCrEu, meaning that it has stronger than usual absorption lines of strontium, chromium and europium. It is also a chemically peculiar star and classified as an Ap star.^[20]

The other two components contribute just 0.23 magnitudes to the apparent magnitude of HN Andromedae. One has an orbital period of 106.3 days, and some orbital parameters can be computed. The other has an orbital period longer than 5000 days.^[16]

Variability

The variability of HN Andromedae can be totally ascribed to the primary component, and is compatible with its stellar rotation; this gives the classification as an α² Canum Venaticorum variable.^[16] Magnetic fields in this star are strong and variable, and this is thought to happen when the magnetic dipole axis in the star is not aligned to the rotation axis.^[24] Also, the distribution of metals, and consequently the surface brightness, is not uniform on the surface, and this causes the brightness observed variation.

References

1. ^¹²³⁴⁵{{cite DR2|396629101528311552}}
2. ^¹²³{{cite journal |title=VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) |journal=CDS/ADC Collection of Electronic Catalogues |pages=II/246 |last1=Cutri |first1=R. M. |last2=Skrutskie |first2=M. F. |last3=Van Dyk |first3=S. |last4=Beichman |first4=C. A. |last5=Carpenter |first5=J. M. |last6=Chester |first6=T. |last7=Cambresy |first7=L. |last8=Evans |first8=T. |last9=Fowler |first9=J. |last10=Gizis |first10=J. |last11=Howard |first11=E. |last12=Huchra |first12=J. |last13=Jarrett |first13=T. |last14=Kopan |first14=E. L. |last15=Kirkpatrick |first15=J. D. |last16=Light |first16=R. M. |last17=Marsh |first17=K. A. |last18=McCallon |first18=H. |last19=Schneider |first19=S. |last20=Stiening |first20=R. |last21=Sykes |first21=M. |last22=Weinberg |first22=M. |last23=Wheaton |first23=W. A. |last24=Wheelock |first24=S. |last25=Zacarias |first25=N. |display-authors=3 |number=2246 |date=June 2003 |bibcode=2003yCat.2246....0C}}
3. ^¹{{Cite journal| doi = 10.1134/S1063773706110065| bibcode=2006AstL...32..759G| title = Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system| journal = Astronomy Letters| volume = 32| issue = 11| pages = 759–771| date = November 2006| last1 = Gontcharov | first1 = G. A.|arxiv = 1606.08053 }}
4. ^¹²{{cite journal | title=Revised Elemental Abundances of the MCP Star HD 8441 | last1=Adelman | first1=S. J. | last2=Caliskan | first2=H. | journal=Baltic Astronomy | volume=13 | pages=35–39 | year=2004 | bibcode=2004BaltA..13...35A}}
5. ^¹²{{cite journal | title=On the Photometric Variability of Very Sharp-lined Cool mCP Stars | last1=Pyper | first1=D. M. | last2=Adelman | first2=S. J. | journal=Publications of the Astronomical Society of the Pacific | volume=129 | issue=980 | pages=104203 | date=October 2017 | bibcode=2017PASP..129j4203P | doi=10.1088/1538-3873/aa7c9e}}
6. ^¹²³⁴⁵⁶⁷{{citation | last1=North | first1=P. | last2=Carquillat | first2=J. -M. | last3=Ginestet | first3=N. | last4=Carrier | first4=F. | last5=Udry | first5=S. | title=Multiplicity among peculiar A stars. I. The AP stars HD 8441 and HD 137909, and the AM stars HD 43478 and HD 96391 | journal=Astronomy and Astrophysics Supplement | volume=130 | issue=2 | pages=223–232 | year=1998 | bibcode=1998A&AS..130..223N | doi=10.1051/aas:1998365 | postscript=. }}
7. ^¹²{{cite journal|bibcode=2016A&A...590A.116J|title=The Nainital-Cape Survey. IV. A search for pulsational variability in 108 chemically peculiar stars|journal=Astronomy and Astrophysics|volume=590|pages=A116|last1=Joshi|first1=S.|last2=Martinez|first2=P.|last3=Chowdhury|first3=S.|last4=Chakradhari|first4=N. K.|last5=Joshi|first5=Y. C.|last6=Van Heerden|first6=P.|last7=Medupe|first7=T.|last8=Kumar|first8=Y. B.|last9=Kuhn|first9=R. B.|year=2016|doi=10.1051/0004-6361/201527242}}

词条	HN Andromedae
释义	System Variability References {{Starbox begin \| name= HN Andromedae }}{{Starbox observe \| epoch=J2000 \| ra={{RA\|01\|24\|18.6762}}^[1] \| dec={{DEC\|+43\|08\|31.6293}}^[1] \| appmag_v= 6.67 – 6.76 variable \| constell=Andromeda }}{{Starbox character \| class=A2pSrCrEu \| appmag_1_passband = B \| appmag_1 = 6.704 \| appmag_2_passband = V \| appmag_2 = 6.676 \| appmag_3_passband = G \| appmag_3 = 6.6505^[1] \| appmag_4_passband = J \| appmag_4 = 6.457^[8] \| appmag_5_passband = H \| appmag_5 = 6.534^[8] \| appmag_6_passband = K \| appmag_6 = 6.495^[8] \| r-i = \| v-r = \| b-v = \| u-b = \| j-h = \| j-k = \| variable = α² CVn }}{{Starbox astrometry \| radial_v= {{val\|3.0\|3.3}}^[12] \| prop_mo_ra={{val\|-4.355\|0.190}} ^[1] \| prop_mo_dec={{val\|-13.258\|0.169}}^[1] \| parallax= 3.437 \| p_error= 0.098 \| parallax_footnote = ^[1] \| dist_ly = \| dist_pc = \| absmag_v = \| absmag_bol = }}{{Starbox orbit \| reference = ^[16] \| primary = \| name = \| period = \| period_unitless = {{val\|106.357\|0.009}} days \| axis = \| axis_unitless = \| eccentricity = {{val\|0.122\|0.010}} \| inclination = \| node = \| periastron = HJD {{val\|2,444,952.21\|1.32}} \| periarg = {{val\|279.76\|4.75}} \| periarg_primary = \| k1 = {{val\|26.85\|0.29}} \| k2 = }}{{Starbox detail \| source = \| component1 = \| mass = {{val\|2.76\|0.18}}^[16] \| mass_mj = \| radius = {{val\|3.86\|0.66}}^[16] \| radius_rj = \| radius_km = \| luminosity = 93^[19] \| luminosity_bolometric = \| luminosity_visual = \| habitable_inner = \| habitable_outer = \| gravity = 3.3^[20] \| temperature = 9,617^[19] \| metal = \| metal_fe = \| rotation = \| rotational_velocity = <2.35^[16] \| age = \| age_myr = \| age_gyr = \| component2 = \| mass2 = \| mass_mj2 = \| radius2 = \| radius_rj2 = \| radius_km2 = \| luminosity2 = \| luminosity_bolometric2 = \| luminosity_visual2 = \| habitable_inner2 = \| habitable_outer2 = \| gravity2 = \| temperature2 = \| metal2 = \| metal2_fe = \| rotation2 = \| rotational_velocity2 = \| age2 = \| age_myr2 = \| age_gyr2 = }}{{Starbox catalog \| names=2MASS J01241868+4308315, BD+42 293, HD 8441, HIP 6560, TYC 2825-2536-1, SAO 37177 }}{{Starbox reference \| }}{{Starbox end}}HN Andromedae (often abbreviated to HN And) is a variable star in the constellation Andromeda. Its apparent visual magnitude varies between 6.67 and 6.76 in a cycle of 69.51 days.^[24] It is classified as an α² Canum Venaticorum variable. System The HN Andromedae system is triple, as seen in periodic radial velocity variations. The primary component is a star that is leaving the main sequence with an absolute magnitude M_v={{val\|-0.03\|0.42}}, dominates the observed spectrum^[16] and its spectral classification is A2pSrCrEu, meaning that it has stronger than usual absorption lines of strontium, chromium and europium. It is also a chemically peculiar star and classified as an Ap star.^[20] The other two components contribute just 0.23 magnitudes to the apparent magnitude of HN Andromedae. One has an orbital period of 106.3 days, and some orbital parameters can be computed. The other has an orbital period longer than 5000 days.^[16] Variability The variability of HN Andromedae can be totally ascribed to the primary component, and is compatible with its stellar rotation; this gives the classification as an α² Canum Venaticorum variable.^[16] Magnetic fields in this star are strong and variable, and this is thought to happen when the magnetic dipole axis in the star is not aligned to the rotation axis.^[24] Also, the distribution of metals, and consequently the surface brightness, is not uniform on the surface, and this causes the brightness observed variation. References 1. ^¹²³⁴⁵{{cite DR2\|396629101528311552}} 2. ^¹²³{{cite journal \|title=VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) \|journal=CDS/ADC Collection of Electronic Catalogues \|pages=II/246 \|last1=Cutri \|first1=R. M. \|last2=Skrutskie \|first2=M. F. \|last3=Van Dyk \|first3=S. \|last4=Beichman \|first4=C. A. \|last5=Carpenter \|first5=J. M. \|last6=Chester \|first6=T. \|last7=Cambresy \|first7=L. \|last8=Evans \|first8=T. \|last9=Fowler \|first9=J. \|last10=Gizis \|first10=J. \|last11=Howard \|first11=E. \|last12=Huchra \|first12=J. \|last13=Jarrett \|first13=T. \|last14=Kopan \|first14=E. L. \|last15=Kirkpatrick \|first15=J. D. \|last16=Light \|first16=R. M. \|last17=Marsh \|first17=K. A. \|last18=McCallon \|first18=H. \|last19=Schneider \|first19=S. \|last20=Stiening \|first20=R. \|last21=Sykes \|first21=M. \|last22=Weinberg \|first22=M. \|last23=Wheaton \|first23=W. A. \|last24=Wheelock \|first24=S. \|last25=Zacarias \|first25=N. \|display-authors=3 \|number=2246 \|date=June 2003 \|bibcode=2003yCat.2246....0C}} 3. ^¹{{Cite journal\| doi = 10.1134/S1063773706110065\| bibcode=2006AstL...32..759G\| title = Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system\| journal = Astronomy Letters\| volume = 32\| issue = 11\| pages = 759–771\| date = November 2006\| last1 = Gontcharov \| first1 = G. A.\|arxiv = 1606.08053 }} 4. ^¹²{{cite journal \| title=Revised Elemental Abundances of the MCP Star HD 8441 \| last1=Adelman \| first1=S. J. \| last2=Caliskan \| first2=H. \| journal=Baltic Astronomy \| volume=13 \| pages=35–39 \| year=2004 \| bibcode=2004BaltA..13...35A}} 5. ^¹²{{cite journal \| title=On the Photometric Variability of Very Sharp-lined Cool mCP Stars \| last1=Pyper \| first1=D. M. \| last2=Adelman \| first2=S. J. \| journal=Publications of the Astronomical Society of the Pacific \| volume=129 \| issue=980 \| pages=104203 \| date=October 2017 \| bibcode=2017PASP..129j4203P \| doi=10.1088/1538-3873/aa7c9e}} 6. ^¹²³⁴⁵⁶⁷{{citation \| last1=North \| first1=P. \| last2=Carquillat \| first2=J. -M. \| last3=Ginestet \| first3=N. \| last4=Carrier \| first4=F. \| last5=Udry \| first5=S. \| title=Multiplicity among peculiar A stars. I. The AP stars HD 8441 and HD 137909, and the AM stars HD 43478 and HD 96391 \| journal=Astronomy and Astrophysics Supplement \| volume=130 \| issue=2 \| pages=223–232 \| year=1998 \| bibcode=1998A&AS..130..223N \| doi=10.1051/aas:1998365 \| postscript=. }} 7. ^¹²{{cite journal\|bibcode=2016A&A...590A.116J\|title=The Nainital-Cape Survey. IV. A search for pulsational variability in 108 chemically peculiar stars\|journal=Astronomy and Astrophysics\|volume=590\|pages=A116\|last1=Joshi\|first1=S.\|last2=Martinez\|first2=P.\|last3=Chowdhury\|first3=S.\|last4=Chakradhari\|first4=N. K.\|last5=Joshi\|first5=Y. C.\|last6=Van Heerden\|first6=P.\|last7=Medupe\|first7=T.\|last8=Kumar\|first8=Y. B.\|last9=Kuhn\|first9=R. B.\|year=2016\|doi=10.1051/0004-6361/201527242}} ^[2]^[3]^[4]^[5]^[6]^[7] }}{{Stars of Andromeda}} 8 : Andromeda (constellation)\|Objects with variable star designations\|2MASS objects\|Hipparcos objects\|Henry Draper Catalogue objects\|Alpha2 Canum Venaticorum variables\|Ap star\|A-type main-sequence stars
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System

Variability

References