“Delta Coronae Borealis”的意思、由来-开放百科全书

Delta Coronae Borealis, Latinized from δ Coronae Borealis, is a variable star in the constellation Corona Borealis. Its apparent magnitude varies regularly between apparent magnitude 4.57 and 4.69, and it is around 170 light-years distant.

δ Coronae Borealis is a yellow giant star of spectral type G3.5III that is around 2.4 times as massive as the Sun and has swollen to 7.4 times its radius. It has a surface temperature of 5180 K.^[23] For most of its existence, Delta Coronae Borealis was a blue-white main sequence star of spectral type B before it ran out of hydrogen fuel in its core. Its luminosity and spectrum suggest it has just crossed the Hertzsprung gap, having finished burning core hydrogen and just begun burning hydrogen in its shell. It is a strong source of X-rays due to its hot corona.^[2]

In 1989, it was noticed that the brightness of δ Coronae Borealis is not constant. Approximately every 45 days, its brightness changes sinusoidally between 4.57 and 4.69, too small to be noticed without close monitoring. The evolutionary state of the star and its probably rotation period mean that the variations may be due to its rotation with different parts of the surface having spots or different temperatures. This would make it an RS Canum Venaticorum variable.^[25] The period has since been refined to 59 days and this is now accepted as the star's rotation period.^[13]

References

1. ^{{cite simbad|title=del CrB|access-date=25 February 2017}}
2. ^{{cite web| first1=James B. | last1=Kaler | title=Delta Coronae Borealis | work=Stars | publisher=University of Illinois | url=http://stars.astro.illinois.edu/sow/deltacrb.html | accessdate=21 November 2014}}
3. ^¹²³⁴⁵⁶{{cite journal|bibcode=2005A&A...431.1027G|title=The X-ray activity of the slowly rotating G giant δ CrB|journal=Astronomy and Astrophysics|volume=431|issue=3|pages=1027–1035|last1=Gondoin|first1=P.|year=2005|doi=10.1051/0004-6361:20041991}}
4. ^¹²³⁴{{cite journal | first=F. | last=van Leeuwen | title=Validation of the New Hipparcos Reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–64 | date=2007 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | arxiv=0708.1752}}
5. ^¹{{cite journal|bibcode= 2016A&A...585A..73N |title= The Penn State - Toruń Centre for Astronomy Planet Search stars |journal= Astronomy and Astrophysics |volume= 585 |pages= A73 |last1= Niedzielski |first1= A. |last2= Deka-Szymankiewicz |first2= B. |last3= Adamczyk |first3= M. |last4= Adamów |first4= M. |last5= Nowak |first5= G. |last6= Wolszczan |first6= A. |year= 2016 |doi= 10.1051/0004-6361/201527362 }}
6. ^¹{{cite DR2|1222932018447710720}}
7. ^¹{{cite journal|bibcode=1989ApJS...71..245K|title=The Perkins Catalog of Revised MK Types for the Cooler Stars|journal=The Astrophysical Journal Supplement Series|volume=71|pages=245|last1=Keenan|first1=Philip C.|last2=McNeil|first2=Raymond C.|year=1989}}
8. ^¹²{{cite journal|author1=Mermilliod, J.-C.|title=Compilation of Eggen's UBV data, transformed to UBV (unpublished)|journal=Catalogue of Eggen's UBV Data., 0 (1986)|pages=0|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1986EgUBV........0M&db_key=AST&nosetcookie=1|date=1986|bibcode= 1986EgUBV........0M }}
9. ^¹²{{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|pages=B/gcvs|display-authors=etal|author1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}
10. ^¹{{cite journal|bibcode=1987PASP...99..183F|title=Delta Coronae Borealis : A chromospherically active giant ?|journal=Publications of the Astronomical Society of the Pacific|volume=99|pages=183|last1=Fernie|first1=J. D.|year=1987}}
11. ^¹{{cite journal|last=Gondoin|first=P.|date=2005|title=The X-ray activity of the slowly rotating G giant δ CrB|journal=Astronomy & Astrophysics|volume=431|issue=3|pages=1027–35| doi= 10.1051/0004-6361:20041991 | bibcode = 2005A&A...431.1027G }}

词条	Delta Coronae Borealis
释义	References {{Starbox begin \| name = δ Coronae Borealis}}{{Starbox observe \| epoch = J2000.0 \| equinox = J2000.0 (ICRS) \| constell = Corona Borealis \| ra = {{RA\|15\|49\|35.64682}}^[1] \|dec= {{DEC\|+26\|04\|06.2065}}^[1] \| appmag_v=4.57 - 4.69^[3] }}{{Starbox character \|class=G5III-IV Fe-1^[4] \|b-v= +0.78^[5] \|u-b= +0.32^[5] \| variable = RS CVn?^[3] }}{{Starbox astrometry \| radial_v = {{Val\|−20.356\|0.035}}^[8] \| prop_mo_ra = -78.83^[1] \| prop_mo_dec = -65.28^[1] \| parallax = 19.7137 \| p_error = 0.1820 \| parallax_footnote = ^[11] \| absmag_v= +1.18 }}{{Starbox detail \| source = \| mass = 2.4^[13] \| radius = 7.4^[13] \| luminosity = 34.3^[13] \| temperature = 5,180^[13] \| gravity = 3.29 \| metal_fe = −0.12 \| rotational_velocity = 4.56 \| rotation = 59^[13] days \| age_myr = 851 }}{{Starbox catalog \| names= δ CrB, 10 Coronae Borealis, BD+26° 2737, HD 141714, HIP 77512, HR 5889, SAO 84019^[1] }}{{Starbox reference \| Simbad=del+crB}}{{Starbox end}} Delta Coronae Borealis, Latinized from δ Coronae Borealis, is a variable star in the constellation Corona Borealis. Its apparent magnitude varies regularly between apparent magnitude 4.57 and 4.69, and it is around 170 light-years distant. δ Coronae Borealis is a yellow giant star of spectral type G3.5III that is around 2.4 times as massive as the Sun and has swollen to 7.4 times its radius. It has a surface temperature of 5180 K.^[23] For most of its existence, Delta Coronae Borealis was a blue-white main sequence star of spectral type B before it ran out of hydrogen fuel in its core. Its luminosity and spectrum suggest it has just crossed the Hertzsprung gap, having finished burning core hydrogen and just begun burning hydrogen in its shell. It is a strong source of X-rays due to its hot corona.^[2] In 1989, it was noticed that the brightness of δ Coronae Borealis is not constant. Approximately every 45 days, its brightness changes sinusoidally between 4.57 and 4.69, too small to be noticed without close monitoring. The evolutionary state of the star and its probably rotation period mean that the variations may be due to its rotation with different parts of the surface having spots or different temperatures. This would make it an RS Canum Venaticorum variable.^[25] The period has since been refined to 59 days and this is now accepted as the star's rotation period.^[13] References 1. ^{{cite simbad\|title=del CrB\|access-date=25 February 2017}} 2. ^{{cite web\| first1=James B. \| last1=Kaler \| title=Delta Coronae Borealis \| work=Stars \| publisher=University of Illinois \| url=http://stars.astro.illinois.edu/sow/deltacrb.html \| accessdate=21 November 2014}} 3. ^¹²³⁴⁵⁶{{cite journal\|bibcode=2005A&A...431.1027G\|title=The X-ray activity of the slowly rotating G giant δ CrB\|journal=Astronomy and Astrophysics\|volume=431\|issue=3\|pages=1027–1035\|last1=Gondoin\|first1=P.\|year=2005\|doi=10.1051/0004-6361:20041991}} 4. ^¹²³⁴{{cite journal \| first=F. \| last=van Leeuwen \| title=Validation of the New Hipparcos Reduction \| journal=Astronomy and Astrophysics \| volume=474 \| issue=2 \| pages=653–64 \| date=2007 \| bibcode=2007A&A...474..653V \| doi=10.1051/0004-6361:20078357 \| arxiv=0708.1752}} 5. ^¹{{cite journal\|bibcode= 2016A&A...585A..73N \|title= The Penn State - Toruń Centre for Astronomy Planet Search stars \|journal= Astronomy and Astrophysics \|volume= 585 \|pages= A73 \|last1= Niedzielski \|first1= A. \|last2= Deka-Szymankiewicz \|first2= B. \|last3= Adamczyk \|first3= M. \|last4= Adamów \|first4= M. \|last5= Nowak \|first5= G. \|last6= Wolszczan \|first6= A. \|year= 2016 \|doi= 10.1051/0004-6361/201527362 }} 6. ^¹{{cite DR2\|1222932018447710720}} 7. ^¹{{cite journal\|bibcode=1989ApJS...71..245K\|title=The Perkins Catalog of Revised MK Types for the Cooler Stars\|journal=The Astrophysical Journal Supplement Series\|volume=71\|pages=245\|last1=Keenan\|first1=Philip C.\|last2=McNeil\|first2=Raymond C.\|year=1989}} 8. ^¹²{{cite journal\|author1=Mermilliod, J.-C.\|title=Compilation of Eggen's UBV data, transformed to UBV (unpublished)\|journal=Catalogue of Eggen's UBV Data., 0 (1986)\|pages=0\|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1986EgUBV........0M&db_key=AST&nosetcookie=1\|date=1986\|bibcode= 1986EgUBV........0M }} 9. ^¹²{{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\|pages=B/gcvs\|display-authors=etal\|author1=Samus\|first1=N. N.\|last2=Durlevich\|first2=O. V.\|year=2009}} 10. ^¹{{cite journal\|bibcode=1987PASP...99..183F\|title=Delta Coronae Borealis : A chromospherically active giant ?\|journal=Publications of the Astronomical Society of the Pacific\|volume=99\|pages=183\|last1=Fernie\|first1=J. D.\|year=1987}} 11. ^¹{{cite journal\|last=Gondoin\|first=P.\|date=2005\|title=The X-ray activity of the slowly rotating G giant δ CrB\|journal=Astronomy & Astrophysics\|volume=431\|issue=3\|pages=1027–35\| doi= 10.1051/0004-6361:20041991 \| bibcode = 2005A&A...431.1027G }} ^[3]^[4]^[5]^[6]^[7]^[8]^[9]^[10]^[11] }}{{Stars of Corona Borealis}} 8 : Corona Borealis\|G-type giants\|Bayer objects\|Flamsteed objects\|Hipparcos objects\|Henry Draper Catalogue objects\|HR objects\|Durchmusterung objects
随便看	Manned space exploration Manned the yards Manned Venus Fly-by Manneh-ye Paeen Manne Island Manneken Pis (film) Mannekind Mannekäng i rött Mannen "Mannenberg" Mannenberg Mannenberg - Is Where it's Happening Mannen som blev miljonar Mannen som blev miljonär Mannequin (1926 film) Mannequin (1933 film) Mannequin Cemetery Mannequin Factory Mannequin Parade Mannequin Rotting in a Taxi-Cab Mannerchar Upazila Manner (confectionary) Mannergarten Mannerim railway station Mannering