Hubbry Logo
Cor CaroliCor CaroliMain
Open search
Cor Caroli
Community hub
Cor Caroli
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Cor Caroli
Cor Caroli
Cor Caroli
View on Wikipedia
from Wikipedia
α Canum Venaticorum
The location of α Canum Venaticorum (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Canes Venatici
α2 CVn
Right ascension 12h 56m 01.66622s[1]
Declination +38° 19′ 06.1541″[1]
Apparent magnitude (V) 2.84 to 2.98[2]
α1 CVn
Right ascension 12h 56m 00.43258s[1]
Declination +38° 18′ 53.3768″[1]
Apparent magnitude (V) 5.60[3]
Characteristics
α2 CVn
Spectral type A0pSiEuHg[4]
U−B color index −0.32[5]
B−V color index −0.12[5]
Variable type α2 CVn
α1 CVn
Spectral type F2V[6]
U−B color index −0.03[7]
B−V color index +0.34[7]
Astrometry
α2 CVn
Radial velocity (Rv)−4.1±0.2[8] km/s
Proper motion (μ) RA: −235.08[1] mas/yr
Dec.: 53.54[1] mas/yr
Parallax (π)32.7227±0.5844 mas[9]
Distance100 ± 2 ly
(30.6 ± 0.5 pc)
Absolute magnitude (MV)0.16±0.08[10]
α1 CVn
Radial velocity (Rv)−0.60 ± 0.9[11] km/s
Proper motion (μ) RA: −232.86[1] mas/yr
Dec.: 55.69[1] mas/yr
Parallax (π)30.6121±0.0666 mas[12]
Distance106.5 ± 0.2 ly
(32.67 ± 0.07 pc)
Details
α2 CVn
Mass2.97±0.07[10] M☉
Radius2.49±0.26[10] R☉
Luminosity101±12[10] L☉
Surface gravity (log g)3.9±0.1[10] cgs
Temperature11,600±500[10] K
Rotation5.46939 d[10]
Rotational velocity (v sin i)18.4±0.5[10] km/s
Age165+60
−70[10] Myr
α1 CVn
Mass1.47±0.15[13] M☉
Radius1.5[13] R☉
Surface gravity (log g)4.25±0.22[13] cgs
Temperature7,080[13] K
Rotational velocity (v sin i)18[14] km/s
Other designations
α CVn, Alpha CVn, 12 CVn, BD+39°2580, ADS 8706 AB, CCDM J12560+3819B[15]
α2 CVn: α CVn A, 12 CVn A, FK5 485, GC 17557, HD 112413, HIP 63125, HR 4915, SAO 63257[15]
α1 CVn: α CVn B, 12 CVn B, GC 17556, HD 112412, HIP 63121, HR 4914, SAO 63256[16]
Database references
SIMBADα2 CVn
α1 CVn

Cor Caroli /ˌkɔːr ˈkærəlaɪ/ is a binary star in the northern constellation of Canes Venatici. It is the brightest star in the constellation, lying at the third magnitude. The International Astronomical Union uses the name "Cor Caroli" specifically for the brighter star of the binary.[17] The system has the Bayer designation Alpha Canum Venaticorum or α Canum Venaticorum.

Nomenclature

[edit]

α Canum Venaticorum, Latinised to Alpha Canum Venaticorum, is the system's Bayer designation. The brighter of the two stars is designated α2 Canum Venaticorum, the fainter α1 Canum Venaticorum.[18]

In the western world Alpha Canum Venaticorum had no name until the 17th century, when it was named Cor Caroli, which means "Charles's Heart". There has been some uncertainty whether it was named in honour of King Charles I of England, who was executed in 1649 during the English Civil War, or of his son, Charles II, who restored the English monarchy to the throne in 1660. The name was coined in 1660 by Sir Charles Scarborough, physician to Charles II, who claimed the star seemed to shine exceptionally brightly on the night of Charles II's return to England. In Star Names, R.H. Allen claimed that Scarborough suggested the name to Edmond Halley and intended it to refer to Charles II.[19] However, Robert Burnham Jr. notes that "the attribution of the name to Halley appears in a report published by J. E. Bode at Berlin in 1801, but seems to have no other verification".[20] In Star Tales, Ian Ridpath points out that the name's first appearance on a star map was in the 1673 chart of Francis Lamb, who labelled it Cor Caroli Regis Martyris ('the heart of Charles the martyred king'), clearly indicating that it was seen as referring to Charles I.[21]

In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[22] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[23] included a table of the first two batches of names approved by the WGSN, which included Cor Caroli for the star α2 Canum Venaticorum.

In Chinese, 常陳 (Cháng Chén), meaning Imperial Guards, refers to an asterism consisting of α Canum Venaticorum, 10 Canum Venaticorum, Beta Canum Venaticorum, 6 Canum Venaticorum, 2 Canum Venaticorum and 67 Ursae Majoris.[24] Consequently, the Chinese name for Alpha Canum Venaticorum itself is 常陳一 (Cháng Chén yī, English: the First Star of Imperial Guards).[25] From this Chinese name, the name Chang Chen was derived.[26]

Stellar properties

[edit]
Cor Caroli seen from northern England on March 1, 2011

Alpha Canum Venaticorum is a binary pair of stars that marks the northern vertex of the asterism known as the Great Diamond or the Diamond of Virgo. The system lies approximately 110 light-years from the Sun.

The two stars are separated by an estimated 650 - 670 Astronomical Units, and orbit a common center of mass with a period around 8,000 years.[27] The pair have a combined apparent magnitude of 2.81. The two stars are 19.6 arcseconds apart in the sky and are easily resolved in small telescopes.

α2 Canum Venaticorum

[edit]
A light curve for α2 Canum Venaticorum, plotted from TESS data[28]

α2 Canum Venaticorum has a spectral type of A0, and has an apparent visual magnitude which varies between 2.84 and 2.98, with a period of 5.47 days.[2] It is a chemically peculiar star with a strong magnetic field, about 5,000 times as strong as the Earth's, and is also classified as an Ap/Bp star.[29] Its atmosphere has overabundances of some elements, such as silicon, mercury and europium. This is thought to be due to some elements sinking down into the star under the force of gravity while others are elevated by radiation pressure.[18][29] This star is the prototype of a class of variable stars, the so-called α2 Canum Venaticorum variables. The strong magnetic field of these stars is believed to produce starspots of enormous extent. Due to these starspots the brightness of α2 Canum Venaticorum stars varies considerably during their rotation.

α1 Canum Venaticorum

[edit]

α1 Canum Venaticorum is an F-type main-sequence star. It is considerably fainter than its companion and has an apparent visual magnitude of approximately 5.60.[3]

Namesakes

[edit]

Cor Caroli was a U.S. Navy Crater-class cargo ship named after the star.

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Cor Caroli

View on Grokipedia
from Grokipedia
Cor Caroli, designated Alpha Canum Venaticorum (α CVn), is the brightest star in the constellation Canes Venatici and a wide located approximately 110 light-years from . The primary component, α² CVn, is a blue-white A0p with an apparent visual magnitude varying between 2.84 and 2.98, making it visible to the under . Its companion, α¹ CVn, is a yellow-white F0V of magnitude 5.6, separated by about 19 arcseconds, equivalent to roughly 650 astronomical units at their distance. This separation suggests an of at least 8,300 years for the pair, first resolved as a double by in 1781. The name "Cor Caroli," meaning "Heart of Charles" in Latin, was assigned in 1725 by , at the suggestion of Sir Charles Scarborough, to honor King Charles II of (though some sources suggest Charles I); prior to this, the star was known in some traditions as the "Lion's Liver." itself was introduced as a constellation by in 1687, representing the hunting dogs held by . Cor Caroli lies about 17.5 degrees south of Alioth (ε UMa) in the Big Dipper's handle, making it easy to locate in the northern spring sky. Physically, the primary star α² CVn is notable for its strong magnetic field exceeding 2,000 times that of Earth, classifying it as the prototype of the Alpha² Canum Venaticorum variable stars, with brightness fluctuations caused by rotating starspots over a 5.47-day period. It has a surface temperature of about 11,450 K, a radius 2.7 times the Sun's, a mass around 3 solar masses, and shines with 113 times the Sun's luminosity, giving it a main-sequence lifetime of roughly 350 million years. The secondary α¹ CVn is cooler at 6,785 K, with a radius 1.7 times solar, mass of 1.5 solar masses, and luminosity of 5.6 Suns, expected to endure for about 2.7 billion years. Observations through small telescopes reveal the pair's striking color contrast, enhancing its appeal to amateur astronomers.

Nomenclature and History

Etymology and Naming Origin

The name Cor Caroli derives from Latin, translating to "Heart of Charles," and is believed to honor one of the English monarchs named Charles during the turbulent . Some historical accounts attribute the naming to King Charles I, who was executed in 1649 during the and subsequently revered as a by Royalists; this interpretation appears in early references such as Francis Lamb's 1686 Ephemerides, where the star is labeled Cor Caroli Regis Martyris ("Heart of Charles the Martyred King"). Others, drawing on contemporary records, link it to King Charles II, whose restoration to the throne in marked a pivotal moment, with the star's prominence that year seen as an auspicious sign. The designation was first documented in 1660 by Sir Charles Scarburgh (also spelled Scarborough), physician to Charles II, in his astronomical , where he proposed the name to commemorate the king's return from exile. Later, in 1725, included Cor Caroli in his star catalog, explicitly crediting Scarburgh's suggestion and associating it with Charles II, solidifying its royal connotation amid post-Restoration loyalty. Alternative theories occasionally suggest a connection to Charles II's own heart or even pre-existing stellar lore equating bright like Sirius with vital "hearts" in ancient traditions, though these lack direct attribution to the name's origin. In , Cor Caroli (α Canum Venaticorum) is known as 常陳一 (Cháng Chén yī), meaning "First Star of Imperial Guards," forming part of the traditional asterism 常陳 (Cháng Chén), which represents elite palace guards and includes several nearby stars in Canes Venaticorum and . This , rooted in ancient Chinese celestial mapping, predates the Western name and reflects the star's role in imperial symbolism rather than royal biography. The α Canum Venaticorum was standardized later in the 17th century following Johann Bayer's system.

Historical Discovery and Designations

Cor Caroli, the brightest star in the constellation Canes Venaticorum, was first recognized as a visual through telescopic observations in the , with resolving the components on April 1, 1781, and measuring their separation of approximately 19 arcseconds. The constellation itself was introduced by Polish astronomer in his 1690 star atlas Firmamentum Sobiescianum sive Uranographia, where he depicted the Hunting Dogs as greyhounds leashed to . Hevelius assigned Greek-letter designations to the stars following the system originated by in his 1603 Uranometria, labeling the brighter component as α Canum Venaticorum despite the constellation not existing in Bayer's original 51 maps. The name "Cor Caroli," meaning "Heart of Charles" in Latin and referencing either King Charles I or II of , first appeared on star charts in the late , possibly originating from English or physician Charles Scarborough to commemorate the Restoration of the monarchy in 1660. In 2016, the (IAU) Working Group on Star Names standardized "Cor Caroli" specifically for the primary component α² Canum Venaticorum, while designating the fainter companion as α¹ Canum Venaticorum, formalizing the binary nomenclature for the system. Early photometric variability in the primary was noted by during his systematic observations at the in the 1830s, where he recorded slight fluctuations in brightness consistent with later classifications as an α² Canum Venaticorum variable. The strong oblique magnetic field of the primary, exceeding 1,000 gauss and responsible for the star's spectral peculiarities and light variations, was discovered in the mid-20th century through spectropolarimetric measurements by Horace W. Babcock, who identified it as one of the first Ap stars with a detectable global field structure. The system has been documented in major astronomical catalogs since the , appearing as 12 Canum Venaticorum in John Flamsteed's 1725 Historia Coelestis Britannica, the first catalog based on telescopic positions. It received identifier HIP 63125 in the 1997 Hipparcos Catalogue, providing initial parallax data of about 28.4 mas. Subsequent observations by the mission, particularly in Data Release 3 (2022), refined the parallax to 32.72 ± 0.58 mas, yielding a distance of approximately 30.6 parsecs (100 light-years) and confirming the system's .

Observation

Location and Visibility

Cor Caroli is situated in the within the constellation , with equatorial coordinates of 12h 56m 01.8s and +38° 19′ 04″ in the J2000 epoch. This positioning places it among the stars following the Big Dipper's handle in , making it relatively easy to locate for northern observers by extending an imaginary line southward from the dipper's outer stars. The star is a prominent member of the Great Diamond asterism, a large springtime pattern spanning about 50 degrees that also includes in , in Virgo, and in Leo. With a combined apparent visual magnitude of 2.81, Cor Caroli is readily visible to the unaided eye from latitudes between 90°N and 52°S, provided skies are clear and dark, though may obscure it in urban areas. Optimal viewing occurs during spring evenings in the , particularly in and May, when the star reaches its highest point () around local midnight in early . From mid-northern latitudes, its seasonal path involves rising in the northeast after dusk, crossing the meridian due north at its peak elevation of about 70–80 degrees, and setting in the northwest before dawn. Although a , the components' separation is insufficient for naked-eye resolution, presenting as a solitary bright point.

Telescopic Appearance

Cor Caroli appears as a striking visual when viewed through a , consisting of a bright primary component (α² Canum Venaticorum) and a fainter secondary (α¹ Canum Venaticorum) separated by approximately 19.2 arcseconds. This angular separation corresponds to a projected physical distance of 650-670 AU between the , based on the system's distance of about 110 light-years from . The position angle of the secondary relative to the primary is currently around 229°, orienting the pair roughly southwest-northeast in the field of view. The primary star presents a sparkling white or bluish-white hue, while the secondary exhibits a contrasting pale or greenish tint, enhancing the visual appeal of the pair despite their differing magnitudes of about 2.9 and 5.5, respectively. These colors can vary slightly in observers' perceptions due to the primary's mild variability, which subtly affects the brightness contrast between the components. The wide separation ensures no mutual eclipses occur, allowing the stars to be observed as distinct points without photometric interference. This binary is readily resolvable with a 3-inch under good seeing conditions, making it an accessible target for astronomers; higher magnifications of 50x or more reveal the color contrast more vividly. Historically, the duplicity was first noted telescopically by in 1781, who measured the initial separation, though earlier observers may have glimpsed it with larger instruments of the era. For modern viewing, aim for clear spring evenings when is high, using medium power to frame the pair against the constellation's faint stars for optimal enjoyment.

System Overview

Binary Configuration

Cor Caroli is a true in which the two stars orbit their common with a of approximately 2:1. The primary has an estimated mass of 2.97 M⊙, while the secondary has an estimated mass of 1.47 M⊙, yielding a total system mass of about 4.44 M⊙. The projected separation between the components is 650–670 AU, corresponding to an angular separation of roughly 19.6 arcseconds. This wide visual binary has been monitored since the , with systematic measurements beginning in the early that confirmed its orbital motion around a common . The wide separation implies an exceeding 8,000 years. Given the large separation, the stars exhibit no significant dynamical interactions, such as mass transfer, common envelope phases, or accretion disks, and thus evolve independently as isolated main-sequence objects. The system age is estimated at 300–500 million years from stellar evolution models and isochrone fitting.

Distance and Proper Motion

The distance to the Cor Caroli binary system is 106.5 ± 0.2 light-years, derived from the Gaia Data Release 3 (DR3) parallax measurement of 30.61 ± 0.07 milliarcseconds (mas). This value represents a significant refinement over earlier astrometric data, providing higher precision for determining the system's position in the Milky Way. The parallax was obtained through Gaia's five-year observation baseline, which improved the accuracy of trigonometric distance estimates for nearby stars by reducing systematic errors compared to previous missions. Historical parallax measurements from the mission in 1997 yielded a value of approximately 28.4 mas for the primary component, corresponding to a of about 115 light-years, but with larger uncertainties due to the shorter observational span and lower precision. The DR3 update enhanced reliability by incorporating more observations and advanced calibration techniques, confirming the system's proximity while adjusting the estimate slightly closer. The of the Cor Caroli system is -233.72 mas/year in and +61.55 mas/year in , indicating its transverse movement across the sky relative to the Sun. This translates to a tangential velocity of approximately 28 km/s. The average of the system is -0.76 km/s, reflecting its motion toward the Solar System along the . Together, these components yield space velocity vectors that place Cor Caroli in the general galactic of nearby , with U, V, and W components consistent with disk population dynamics (U ≈ -15 km/s, V ≈ 0 km/s, W ≈ 10 km/s, relative to the local standard of rest). Membership of Cor Caroli in the Moving Group has been debated, with some kinematic analyses suggesting possible association based on shared velocity patterns, but recent data do not confirm it due to discrepancies in age and composition indicators. The system's motion aligns broadly with the group's parameters but lacks definitive evidence for co-motion or shared origin.

Primary Component

Physical Properties

The primary component of the Cor Caroli system, designated α² CVn or HD 112413, is a chemically peculiar main-sequence star of spectral type A0p. This classification indicates enhanced abundances of elements such as , , and mercury due to processes in its atmosphere. Its is approximately 11,600 K, giving it a blue-white hue, and its apparent visual magnitude varies between 2.84 and 2.98. Key stellar parameters include a mass of 2.97 ± 0.10 , a radius of 2.49 ± 0.10 R⊙, and a luminosity of 101 , consistent with models for A-type stars at a distance of approximately 100 light-years (as of DR3, 2022). The surface gravity is log g ≈ 4.0, reflecting its main-sequence status. The star exhibits moderate rotation, with a projected equatorial velocity v sin i ≈ 18 km/s, and its age is estimated at 165 million years (95–225 million years range) from isochrone fitting, shared with the binary companion.

Variability Characteristics

Cor Caroli's primary component, α² CVn, serves as the prototype for the α² CVn class of chemically peculiar main-sequence stars, which display periodic photometric variations of small amplitude due to rotational modulation of surface inhomogeneities. The visual brightness fluctuates by 0.14 magnitudes, spanning a range of 2.84 to 2.98 in the , with the exhibiting double waves corresponding to effective gravity and temperature spots. This variability is strictly periodic with a rotation period of 5.46915 days, during which the star's obliquely rotating magnetic field brings enhanced elemental abundances in and out of view, altering the emergent flux. Accompanying the photometric changes are spectral variations, manifested as periodic shifts in the equivalent widths of lines from elements such as silicon (Si), europium (Eu), and mercury (Hg), which align precisely with the rotational cycle. The variability was initially noted in the late through observations of intensity changes, with detailed photometric and spectroscopic analysis commencing in the early ; the periodic nature was established by Farnsworth in 1932, and the α² CVn type was formally defined in the within the framework of classifications. Ongoing monitoring by the American Association of Observers (AAVSO) has tracked the 's behavior, revealing no long-term trends or deviations in period or amplitude since the launch of the mission, confirming its rotational characteristics.

Secondary Component

Physical Properties

The secondary component of the Cor Caroli system, designated α¹ CVn or HD 112412, is a normal main-sequence of type F0V. This indicates a hydrogen-fusing with a , solar-like structure, lacking the peculiarities seen in the primary component. Its is 6,785 , giving it a yellow-white hue typical of F-type stars, and it maintains a fixed apparent visual magnitude of 5.60, contributing a steady of 5.6 L⊙ to the system. Key stellar parameters include a mass of 1.5 M⊙ and a radius of 1.7 R⊙, consistent with models for unevolved F dwarfs at the system's distance of 115 light-years. The star exhibits no photometric variability, underscoring its stability compared to the magnetically active primary. These properties suggest an age of around 350 million years for α¹ CVn, aligning with the system's overall evolutionary timeline and indicating it is less evolved than its companion, having spent most of its life quietly fusing hydrogen in its core. This age estimate derives from isochrone fitting and the binary's shared formation history, placing the star firmly in the middle of its main-sequence lifetime of about 2.7 billion years.

Role in the Binary System

The secondary component, designated α CVn B, acts as the less massive partner in the Cor Caroli , with an estimated mass of 1.5 solar masses compared to the primary's 3.0 solar masses. It orbits the more massive α CVn A, following its gravitational influence in a wide visual binary configuration, where the projected separation is approximately 675 AU based on the 19 arcsecond at the system's 115 distance. The is estimated at a minimum of 8,300 years, inferred from the relative between the components, which has been tracked consistently over 236 years with a position angle change of 3 arcseconds. The extensive orbital separation precludes significant tidal forces, resulting in no and permitting independent rotation for each ; consequently, their spectra remain separable without blending from mutual Doppler shifts. As a visual companion resolvable in small telescopes, α CVn B—a F0V main-sequence —serves as an essential benchmark for normal A/F-type stellar characteristics, facilitating comparative studies against the chemically peculiar, magnetic primary. The secondary's post-main-sequence evolution will involve expansion into a red giant phase after exhausting its core hydrogen on a timescale of roughly 2.7 billion years, far exceeding the binary's orbital period and thus ensuring minimal dynamical interference between the components during this process. Note: Recent Gaia DR3 measurements (as of 2022) suggest a system distance of approximately 100 light-years, which would adjust the projected separation to about 583 AU; further confirmation pending. [Gaia DR3 via SIMBAD]

Scientific Importance

Magnetic Field and Spectral Peculiarities

The primary star α² CVn in the Cor Caroli system is characterized by a strong, organized that follows the oblique rotator model, where the magnetic axis is inclined relative to the rotation axis, leading to periodic variations in the observed field components as the star rotates. This field is dominated by a configuration with a polar strength of approximately 6 kG, accompanied by a minor quadrupolar contribution of about 1 kG, as determined from magnetic Doppler imaging using Stokes parameter profiles. The longitudinal (line-of-sight) component of the varies between roughly -3,100 G and +5,000 G over the period of 5.47 days, reflecting the modulation due to the obliquity of the . These measurements have been obtained primarily through Zeeman splitting in lines, where the splitting provides direct insight into the field's strength and geometry. Recent high-precision spectropolarimetry with the ESPaDOnS instrument at the Canada-France-Hawaii , conducted from 2006 to 2012, has confirmed the field's complex but stable topology, showing consistency with earlier mappings and no significant evolution over a . The origin of this is attributed to the field hypothesis, wherein remnants of from the star's cloud are preserved through stable configurations in the radiative stellar interior, resisting decay over the main-sequence lifetime. In Ap stars like α² CVn, the field's stability arises from the absence of convective motions in and , allowing the field lines to remain frozen into the stably stratified plasma without significant or reconnection. This nature explains the lack of observed secular changes in the field's strength or structure, as supported by long-term monitoring. Furthermore, the strong stabilizes the outer atmosphere against and , creating a calm environment conducive to atomic processes that drive the observed chemical peculiarities. Chemically, α² CVn displays marked peculiarities typical of SiEuHg-type Ap stars, with significant overabundances of certain elements due to radiative and gravitational settling in the diffusion-friendly atmosphere. is overabundant by about 10 times the solar value (log ε(Si) ≈ 7.75 vs. solar 7.55), by roughly 1,000 times (log ε(Eu) ≈ 1.75 vs. solar -0.52), and mercury by up to 10,000 times (log ε(Hg) ≈ 7.0 vs. solar 3.0), as derived from detailed spectrum synthesis of and optical lines. In contrast, and calcium are underabundant, with He depleted by a factor of ~10 (log ε(He) ≈ 10.5 vs. solar 11.0) and Ca similarly reduced (log ε(Ca) ≈ 5.8 vs. solar 6.34), reflecting downward diffusion of these ions in the magnetic field-influenced zones. These anomalies are not uniform across the surface but are patchy, concentrated in magnetic "spots" where is enhanced. The spectral lines of α² CVn exhibit variability synchronized with the rotation period, arising from the co-rotating chemical inhomogeneities and geometry that alter line profiles as different surface regions come into view. Particularly prominent are the strong lines of rare-earth elements such as , , and , which show enhanced intensities and wavelength shifts due to the overabundances and Zeeman effects, making α² CVn a prototypical example for studying these phenomena. This rotational variability in line strengths and shapes provides key diagnostics for mapping both the abundance distributions and the underlying magnetic structure.

Research and Prototypical Role

α² CVn, the primary component of the Cor Caroli , serves as the prototype for magnetic chemically peculiar Ap stars and defines the class of α² CVn variables, which exhibit rotational modulation due to surface chemical inhomogeneities and . These variables, also known as oblique rotators, display periodic photometric and variations driven by the star's , with α² CVn's 5.47-day period establishing the benchmark for this variability type. Classified as a chemically peculiar Ap star by Antonia Maury in 1897, its strong was discovered by H. W. Babcock in 1952, highlighting the role of organized in creating surface abundance anomalies through inhibition of atomic diffusion. Key research on α² CVn has focused on testing models of stable fossil magnetic fields, which persist in non-convective Ap star interiors without dynamo generation, contrasting with convective dynamo processes in cooler stars. Diffusion models demonstrate how radiative levitation and gravitational settling, modulated by the , produce the observed overabundances of elements like , , and on specific surface regions. Detailed mapping of chemical abundances via spectropolarimetry reveals these enhancements concentrated in magnetically confined patches, providing insights into atmospheric transport processes. Additionally, while Ap stars hold potential for asteroseismology to probe internal magnetic structures and evolution, no pulsations have been detected in α² CVn despite targeted observations. Recent studies have leveraged space-based data to refine models of α² CVn's variability and geometry. The Gaia DR3 release in 2022 improved astrometric parameters, including distance (approximately 30.6 parsecs or 100 light-years) and , enhancing constraints on the system's and binary nature. (TESS) light curves from 2018 onward have enabled detailed modeling of photometric variations, attributing them to a tilted, offset interacting with a dynamical . Zeeman-Doppler imaging, applied through high-resolution spectropolarimetry, has reconstructed the surface magnetic topology—dominated by a dipolar component—and correlated chemical spots, confirming the oblique rotator paradigm. α² CVn's contributions extend to broader stellar , particularly in elucidating A-type star evolution, where influence and inhibit , altering surface compositions and loss. As a bright, well-characterized system, it acts as a benchmark for spectropolarimetry, validating techniques for mapping weak fields and abundance patterns in other Ap stars. However, gaps persist: direct resolved of surface spots remains unavailable, with reliance on indirect tomographic methods, and the binary's —estimated at thousands of years due to the 19.6-arcsecond separation—lacks observational confirmation from orbital motion.

Namesakes and Cultural References

Astronomical Namesakes

The primary astronomical namesake of Cor Caroli is the USS Cor Caroli (AK-91), a Crater-class commissioned by the during . Launched on March 19, 1943, as the Betsy Ross under a Maritime Commission contract, the vessel was acquired and renamed by the on March 31, 1943, and manned by a U.S. crew for operations. It served primarily in the Pacific Theater, supporting amphibious assaults and supply missions, including the capture and occupation of from July 27 to August 15, 1944, earning one battle star for its wartime contributions. Decommissioned on 30 November 1945 and returned to the War Shipping Administration on 2 December 1945, the ship was placed in the and eventually sunk as an on 26 May 1978, approximately 16 miles off the coast of Hilton Head, . No minor planets, lunar features, or major observatories bear the name Cor Caroli, though the star itself serves as a benchmark entry in astronomical databases such as , facilitating research on its spectral and variability properties.

Historical and Cultural Mentions

The name Cor Caroli, meaning "Heart of Charles," originated in the as a tribute tied to the , when English physician Sir Charles Scarborough proposed designating the star Cor Caroli Regis Martyris ("Heart of ") to honor the executed King Charles I in 1649. This royal association was further propagated by astronomer , who included the name in his 1678 , reflecting loyalty to the restored monarchy under Charles II. In 19th-century astronomy literature, Cor Caroli appeared frequently as a notable in , often highlighted for its visibility and historical nomenclature; for instance, William H. Smyth described it in his 1844 Cycle of Celestial Objects as a worthy of telescopic observation, emphasizing its patriotic naming origin (though incorrectly attributing it to Charles II). The star's "heart" symbolism extended into heraldic motifs, where it was illustrated within a crowned heart on the collar of the constellation's southern dog in Johann Bode's 1801 Uranographia, evoking themes of royal devotion and fidelity akin to hunting dogs in traditional coats of arms. Unlike ancient constellations with rich mythological ties, Cor Caroli lacks major myths due to Canes Venatici's modern invention in 1687, but it has entered modern through . In the universe, the Cor Caroli system features as a planetary location in the Alpha Quadrant, including the inhabited world Cor Caroli V and its appearance in The Next Generation episode "," where the USS Enterprise-D encounters a plague outbreak there. The officially standardized the name Cor Caroli in 2016 as part of its efforts to recognize traditional stellar designations.

References

  1. http://stars.astro.illinois.edu/sow/corcaroli.html
  2. https://www.britannica.com/place/Cor-Caroli
  3. https://earthsky.org/brightest-stars/cor-caroli-heart-of-charles/
  4. https://www.astronomy.com/science/cor-caroli-the-pearl-cluster-ngc-3766-and-the-leo-triplet/
  5. http://www.ianridpath.com/startales/canesvenatici.html
  6. https://www.constellationsofwords.com/cor-caroli/
  7. https://hk.space.museum/tc/web/spm/resources/teachers-corner/constellations-and-myths/glossary-of-bright-stars.html
  8. https://www.star-facts.com/cor-caroli/
  9. http://www.ianridpath.com/startales/caneshevelius.html
  10. https://www.lindahall.org/experience/digital-exhibitions/out-of-this-world/22-the-innovations-of-hevelius-1690-1731/
  11. https://iauarchive.eso.org/public/themes/naming_stars/
  12. https://archive.org/details/Resultsastronom00Hers
  13. https://adsabs.harvard.edu/full/1977ApJ...212..141B
  14. https://www.universeguide.com/star/63125/corcaroli
  15. https://gea.esac.esa.int/archive/
  16. https://stardate.org/stargazing-tip/cor-caroli-5
  17. https://in-the-sky.org/data/object.php?id=TYC3021-2645-1
  18. https://theskylive.com/sky/stars/cor-caroli-alpha2-canum-venaticorum-star
  19. https://nineplanets.org/cor-caroli/
  20. http://www.theskyscrapers.org/spring-double-stars
  21. https://www.astronomy.com/observing/binocular-universe-double-duty/
  22. https://iopscience.iop.org/article/10.3847/1538-4357/ac82b9
  23. http://cdsarc.u-strasbg.fr/afoev/var/eacvn.htx
  24. https://ui.adsabs.harvard.edu/abs/1932ApJ....76..313F/abstract
  25. http://www.sai.msu.su/gcvs/gcvs/vartype.htm
  26. http://www.alcyone.de/SIT/mainstars/SIT000393.htm
  27. https://www.aanda.org/articles/aa/pdf/2002/26/aah3300.pdf
  28. https://arxiv.org/pdf/1310.5265
  29. https://www.aanda.org/articles/aa/full/2006/18/aa1980-04/aa1980-04.html
  30. https://pubmed.ncbi.nlm.nih.gov/15483604/
  31. https://academic.oup.com/mnras/article/356/4/1256/1010709
  32. https://www.aanda.org/articles/aa/pdf/2010/05/aa13860-09.pdf
  33. https://www.cambridge.org/core/books/spectral-atlas-for-amateur-astronomers/chemically-peculiar-cp-stars/B2A95C8FDC974F3CE651300588459644
  34. https://ui.adsabs.harvard.edu/abs/1952ApJ...116....8B
  35. https://royalsocietypublishing.org/doi/10.1098/rsos.160271
  36. https://academic.oup.com/mnras/article/444/2/1442/1749647
  37. https://www.aanda.org/articles/aa/full_html/2009/40/aa11931-09/aa11931-09.html
  38. https://www.aanda.org/articles/aa/full_html/2023/06/aa43940-22/aa43940-22.html
  39. https://academic.oup.com/mnras/article/313/4/823/1088396
  40. https://www.history.navy.mil/research/histories/ship-histories/danfs/c/cor-caroli.html
  41. https://vesselhistory.marad.dot.gov/ShipHistory/Detail/516
  42. https://memory-alpha.fandom.com/wiki/Cor_Caroli_V
Add your contribution
Related Hubs
User Avatar
No comments yet.