৫৫ ক্যানক্রি: সংশোধিত সংস্করণের মধ্যে পার্থক্য
বিষয়বস্তু বিয়োগ হয়েছে বিষয়বস্তু যোগ হয়েছে
অ ৫৫ ক্রান্তি-কে ৫৫ ক্যানক্রি-এ সরানো হয়েছে |
formatting, পরিভাষা, অনুবাদ |
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১ নং লাইন:
{| class="toccolours" style="float: right; clear: right;
margin: 0 0 1em 1em;" |+ style="margin-left: inherit;" | '''
|-
! style="background-color: #FFFFC0;" colspan="3"
| পর্যবেক্ষণকৃত উপাত্ত<br/><small>[[ইপক (জ্যোতির্বিজ্ঞান)|ইপক]]
[[জে২০০০.০]]</small>
|-
| '''
| '''
| '''
|-
| '''[[তারামণ্ডল]]'''<br>([[
| [[কর্কট রাশি|কর্কট]]
| [[কর্কট রাশি|কর্কট]]
|-
| '''[[বিষুবাংশ]]'''
২০ ⟶ ২৬ নং লাইন:
| {{DEC|+২৮|১৯|৫৯}}
|-
| '''[[
| ৫.৯৫
| ১৩.১৫
|-
! style="background-color: #FFFFC0;" colspan="3"
| বৈশিষ্ট্য |-
| '''[[নাক্ষত্রিক শ্রেণীবিন্যাস|বর্ণালী ধরণ]]'''
| জি৮ভি
|
|-
| '''
| ০.৬৫
| ১.২১
|-
| '''
| ০.৮৬
| ১.৬৬
|-
| '''[[
| নেই
| অজ্ঞাত
|-
! style="background-color: #FFFFC0;" colspan="3"
| [[জ্যোতির্মিতি]] |-
| '''[[
| ২৭.৩
| ?
|-
| '''[[
|
-২৩৪.৪০ [[মিলিআর্কসেকেন্ড]]/[[বছর]]
| ?
|-
| '''[[লম্বন]] <small>(π)</small>'''
| ৭৯.৮০ ± ০.৮৪ [[
| ?
|-
| '''[[দূরত্ব]]'''
| ৪০.৯ ± ০.৪ [[আলোকবর্ষ]] <br /> (১২.৫ ± ০.১ [[
| ?
|-
| '''[[
| ৫.৪৬
| ১২.৬৬
|-
! style="background-color: #FFFFC0;" colspan="3"
| |-
| '''[[ভর]]'''
| ০.৯৫ ± ০.১<ref name="marcy"/> [[
☉</sub>]] | ০.১৩ [[
|-
| '''[[ব্যাসার্ধ]]'''
| ০.৯৬<ref name=apj531>{{cite journal
| last=Henry | first=Gregory W.
| coauthors=Baliunas, Sallie L.; Donahue, Robert
A.; Fekel, Francis C.; Soon, Willie | title=Photometric and Ca II H and K
Spectroscopic Variations in Nearby Sun-like Stars with Planets. III. | journal=The Astrophysical Journal
| year=2000 | volume=531 | issue=1 | pages=415-
437 | url=http://adsabs.harvard.edu/cgi-bin/bib_query?
2000ApJ...531..415H | accessdate=2007-11-08 }}</ref> [[ | ০.৩০ [[
|-
| '''[[উজ্জ্বলতা]]'''
| ০.৬৩<ref name=apj531/> [[
sub>]]
| ০.০০৭৬ [[সৌর উজ্জ্বলতা|''L''<sub>☉</sub>]]
|-
| '''[[তাপমাত্রা]]'''
| ৫২৫০<ref name=apj531/> [[
| ?
|-
| '''[[
| ১৮৬%<ref name=marcy/>
| ?
|-
| '''[[নাক্ষত্রিক ঘূর্ণন|ঘূর্ণন]]'''
| ৪২.২<ref name="marcy"/> [[দিন]]
| ?
|-
| '''[[
| ৪.৫×১০<sup>৯</sup><ref name=apj531/>
[[বছর]] | ?
|-
! style="background-color: #FFFFC0;" colspan="3"
| [[তারা তালিকা|অন্যান্য বিবরণ]]
|-
| colspan="3" | <div style="width: 350px;">ρ<sup>
1</sup> ক্যিনক্রি, [[গ্লিজে তালিকা|জি১]] ৩২৪, [[Bonner
Durchmusterung|বিডি]] +২৮°১৬৬০, [[হেনরি ড্র্যাপার
তালিকা|এইচডি]] ৭৫৭৩২
'''৫৫ ক্যানক্রি এ'''
[[Harvard Revised catalogue|এইচআর]] ৩৫২২, [[
Luyten Half-Second catalogue|এলএইচএস]]
২০৬২, [[Luyten Two-Tenths catalogue|এলটিটি]]
১২৩১০, [[General Catalogue of Trigonometric
Parallaxes|জিসিটিপি]] ২১১৭.০০, [[Smithsonian
Astrophysical Observatory Star Catalog|সাও]]
৮০৪৭৮, এলএফটি ৬০৯, [[Hipparcos
catalogue|হিপ]] ৪৩৫৮৭
'''৫৫ ক্যানক্রি বি'''
[[Luyten Half-Second catalogue|এলএইচএস]]
২০৬৩, [[Luyten Two-Tenths catalogue|এলটিটি]]
১২৩১১, এলএফটি ৬১০</div>
|}
'''৫৫ ক্যানক্রি''' ([[ইংরেজি]]: 55 cancri; {{IPA|/ˈkæŋkriː/
}}, ইংরেজিতে কখনও কখনও ক্যানক্রাই নামে উচ্চারিত হয়) হচ্ছে [[কর্কট
রাশি|কর্কট রাশিতে]] অবস্থিত একটি [[যুগল তারা]]। এটি পৃথিবী থেকে প্রায়
৪১ [[আলোকবর্ষ]] দূরে অবস্থিত । ৫৫ ক্যানক্রির জগতে একটি [[হলদে
বামন]] [[তারা]] (৫৫ ক্যানক্রি এ) অবস্থিত যেটি অনেকটা আমাদের সূর্যের
মত দেখতে।
<!--'''55 Cancri''' ({{pronEng|ˈkæŋkraɪ}} or {{IPA|
/ˈkæŋkriː/}}, abbreviated 55 Cnc) is a [[binary
star]] located around 41 [[light-year]]s away in the
constellation [[Cancer (constellation)|Cancer]]. It
has the [[Bayer designation]] '''Rho<sup>1</sup>
Cancri'''. The system contains a [[yellow dwarf]] [[
star]] (55 Cancri A) similar to our [[Sun]] and a [[red
dwarf]] (55 Cancri B). The two components are
separated by over 1000 times the distance from
the [[Earth]] to the Sun.
[[2008|As of 2008]], five [[extrasolar planet]]s are
known in orbit around 55 Cancri A. Four of the
planets are comparable to [[Jupiter]] in mass, while
the innermost planet has a mass similar to that of
[[Neptune]]. The 55 Cancri system was the first
known five-planet extrasolar [[planetary system]].
55 Cancri A is ranked 63rd in the list of top 100
target stars for the [[NASA]] [[Terrestrial Planet
Finder]] mission.<ref>{{cite web|url=http://sco.
stsci.edu/tpf_top100/index.php|title=TPF-C Top
100|accessmonthday=4 July|accessyear=2006}}
</ref>-->
==নাম==
<!--"55 Cancri", the star's [[Flamsteed
designation|Flamsteed number]], is seen more
often than its [[Bayer designation]] "Rho<sup>1</
sup> Cancri". The latter is used by those who feel
that it should be preferred to the Flamsteed number
— as is usually done; e.g., [[Tau Bootis]] is almost
never called "4 Bootis" — but in this case the
superscript in "Rho<sup>1</sup>" makes the
Bayer designation rather cumbersome, so that "55
Cancri" is the more commonly used name for this
star.-->
==দূরত্ব এবং দর্শনকাল==
<!--The 55 Cancri system is located fairly close to
our [[solar system]]: the [[Hipparcos]] [[astrometry]]
[[satellite]] measured the [[parallax]] of 55 Cancri A
as 79.80 [[milliarcsecond]]s, corresponding to a
distance of 12.5 [[parsec]]s.<ref>{{cite web|url=
http://vizier.u-strasbg.fr/viz-bin/VizieR-S?HIP%
2043587|title=HIP 43587|work=The Hipparcos and
Tycho Catalogues|publisher=ESA|year=1997
|accessmonthday=30 June|accessyear=2006}}</
ref> 55 Cancri A has an [[apparent magnitude]] of 5
.95, making it visible through [[binoculars]]. It is just
visible to the [[naked eye]] under very dark skies.
The red dwarf 55 Cancri B is of the 13th magnitude
and only visible through a [[telescope]].-->
==তারা জগতের উপাদানসমূহ==
<!--The primary star 55 Cancri A is a yellow dwarf
star of [[main sequence]] spectral type G8V. It is
smaller in radius and slightly less massive than our
Sun, and so is cooler and less [[
luminosity|luminous]]. The star has little or no
variability and only low emission from its
chromosphere.<ref name="marcy"/>
55 Cancri A is more enriched than our sun in
elements heavier than [[helium]], with 186% the
solar abundance of [[iron]]; it is therefore classified
as a rare "super [[metal-rich]]" (SMR) star.<ref
name="marcy">{{cite journal|url=http://www.
citebase.org/cgi-bin/citations?id=oai:arXiv.org:
astro-ph/0207294|author=Marcy, G. et al.|title=A
planet at 5 AU Around 55 Cancri|journal=[[The
Astrophysical Journal]]|volume=581|pages=1375
– 1388|year=2002}}</ref> This abundance
of metal makes estimating the star's age and mass
difficult, as [[stellar evolution|evolutionary]] models
are less well defined for such stars. One estimate
based on [[chromosphere|chromospheric]] activity
suggests an age of around 5,500 million [[year]]s.
<ref>{{cite journal|url=http://cdsads.u-strasbg.fr/
cgi-bin/nph-bib_query?2005A%26A...443..609
S&db_key=AST&nosetcookie=1|author=Saffe, C.
et al.|title=On the Ages of Exoplanet Host
Stars|journal=[[Astronomy and Astrophysics]]
|volume=443|issue=2|pages=609 – 626
|year=2005}}</ref>
A hypothesis for the high metal content in SMR
dwarf stars is that material enriched in heavy
elements fell into the atmosphere from a [[
protoplanetary disk]]. This would pollute the star's
external layers, resulting in a higher than normal
metallicity. The lack of a deep [[convection zone]]
would mean that the outer layers would retain
higher abundance ratios of these heavy elements
.<ref>{{cite news
| last=Pasquini | first=Luca | coauthors=Hatzes,
Artie
| date=July 6, 2007 | publisher=ESO
| title=Star Surface Polluted by Planetary Debris
| url=http://www.eso.org/public/outreach/press-rel
/pr-2007/pr-29-07.html | accessdate=2007-11-08 }}</ref>
Observation of 55 Cancri A in the [[Submillimetre
astronomy|submillimeter]] region of the spectrum
have thus far failed to detect any associated dust.
The upper limit on emissions within 100 AU
of this star is about 850 [[Jansky|mJy]], at a
wavelength of 850 μm. This limits the total
mass of fine dust around the star to less than 0.
01% of the Earth's mass. Of course this does not
exclude the existence of an asteroid belt or the
equivalent of a [[Kuiper belt]].<ref>{{cite journal
| last=Jayawardhana | first=Ray
| coauthors=Holland, W. S.; Kalas, P.; Greaves, J.
S.; Dent, W. R. F.; Wyatt, M. C.; Marcy, G. W. | title=New Submillimeter Limits on Dust in the 55
Cancri Planetary System | journal=The Astrophysical Journal
| year=2002 | volume=570 | issue=2 | pages=L93-
L96 | url=http://www.journals.uchicago.edu/ApJ/journal/
issues/ApJL/v570n2/16185/16185.html | accessdate=2007-11-07 }}</ref>
55 Cancri B is a red dwarf star located at an
estimated distance of 1065 [[Astronomical unit|AU]]
from the primary star,<ref>{{cite journal|url=http://
www-lep.gsfc.nasa.gov/code693/esp_papers/web
/ps2/eggenberger_43.ps|format=[[PostScript]]
|author=Eggenberger, A. et al.|title=Planets in
Binaries|journal=Scientific Frontiers in Research
on Extrasolar Planets|volume=294|pages=43
– 46|year=2003}}</ref> and is much less
massive and luminous than our Sun. Despite their
wide separation, the two stars appear to be
gravitationally bound, as they share a common [[
proper motion]].<ref name="marcy"/> There are
indications that component B may itself be a
double star, though this is by no means certain.
<ref>{{cite journal|url=http://fr.arxiv.org/abs/astro-
ph/0603836|author=Raghavan, D. et al.|title=Two
Suns in The Sky: Stellar Multiplicity in Exoplanet
Systems|journal=[[The Astrophysical Journal]] (
accepted)|year=2006|volume=646|pages=523-
542}}</ref>-->
==গ্রহ জগৎ==
[[Image:55CncInnerOrbits.
svg|thumb|left|Comparison of the orbits of the inner
planets of 55 Cancri (black) with the planets of our
solar system.]]
<!--In 1997, the discovery of a [[51 Pegasi]]-like
planet [[orbit]]ing 55 Cancri A was announced,
together with the planet of [[Tau Boötis]] and the
inner planet of [[Upsilon Andromedae]].<ref>{{cite
journal|url=http://www.journals.uchicago.edu/doi/
full/10.1086/310444|author=Butler, R. et al.|title=
Three New 51 Pegasi-Type Planets|journal=[[The
Astrophysical Journal]]|volume=474|year=1997
|pages=L115 – L118}}</ref> The planet was
discovered by measuring the star's [[radial velocity
]], which showed a periodicity of around 14.7 [[day
]]s corresponding to a planet at least 78% of the
mass of [[Jupiter]]. This planet was designated [[55
Cancri b]], though to distinguish it from the star 55
Cancri B it is occasionally referred to as 55 Cancri
Ab. The radial velocity measurements still showed
a drift unaccounted-for by this planet, which could
be explained by the [[gravity|gravitational]]
influence of a more distant object.
In 1998 the discovery of a possible dust disk
around 55 Cancri A was announced.<ref>{{cite
journal|url=http://www.nature.com/cgi-taf/
DynaPage.taf?file=/nature/journal/v395/n6704/
abs/395775a0_fs.html|author=Trilling, D., Brown.
R|title=A circumstellar dust disk around a star with
a known planetary companion|journal=[[Nature (
journal)|Nature]]|volume=395|pages=775 –
777|year=1998}}</ref> Calculations gave the disk
radius at least 40 AU, similar to the [[Kuiper
belt]] in our solar system, with an inclination of 25°
with respect to the plane of the sky. However, the
discovery could not be verified and was later
deemed to be spurious, caused instead by
background radiation.<ref>{{cite journal|url=http://
adsabs.harvard.edu/cgi-bin/nph-bib_query?
bibcode=2001AJ....121..525S&db_key=AST&high
=3cab10bb0320924|author=Schneider, G. et al.
|title=NICMOS Coronagraphic Observations of 55
Cancri|journal=The Astronomical Journal|volume=
121|issue=1|pages=525 – 537|year=2001
}}</ref>-->
[[Image:Extrasolar planet NASA2.jpg|thumb|right|
250px|Our [[solar system]] compared with the solar
system of 55 Cancri]]
<!--After making further radial velocity
measurements, a planet orbiting at a distance of
around 5 AU was announced in 2002.<ref name
="marcy" /> This planet received the designation
[[55 Cancri d]]. At the time of discovery, the planet
was thought to be in an orbit of mild [[eccentricity (
orbit)|eccentricity]] (close to 0.1), however this
value was increased by later measurements. Even
after accounting for these two planets, a periodicity
at 43 days remained, possibly due to a third planet.
Measurements of the star suggested that this was
close to the star's rotation period, which raised the
possibility that the 43-day signal was caused by
stellar activity. This possible planet received the
designation [[55 Cancri c]].
In 2004 a [[Neptune]]-mass planet designated [[55
Cancri e]] was announced in a 2.8-day orbit.<ref>
{{cite journal|url=http://xxx.lanl.gov/abs/astro-ph/
0408585|author=McArthur, B. et al.|title=Detection
of a NEPTUNE-mass planet in the ρ<sup>1</sup>
Cnc system using the Hobby-Eberly
Telescope|journal=[[The Astrophysical Journal]]
|volume=614|year=2004|pages=L81 – L84
}}</ref> This planet may either be a small [[gas
giant]] or a large [[terrestrial planet]]. The
measurements that led to the discovery of this
planet also confirmed the existence of 55 Cancri c.
In addition, astrometric measurements made by the
[[Hubble Space Telescope]] led to an estimate of
the [[inclination]] of the orbit of the outer planet:
around 53° with respect to the plane of the sky.
Assuming the system is [[coplanarity|coplanar]], this
means the [[true mass]]es of the planets are around
25% greater than the lower limits measured by the
radial velocity method.
[[Image:55cnc.jpg|thumb|right|250px|55 Cnc planets
]]
In 2005 the existence of planet e was
questioned by [[Jack Wisdom]] in a reanalysis of
the data.<ref>{{cite journal|url=http://swiss.csail.
mit.edu/users/wisdom/planet.ps|format=[[
PostScript]]|journal=[[The Astrophysical Journal]]
Letters (submitted)|author=Wisdom, J.|title=
Evidence of a Neptune-Sized Planet in the ρ
<sup>1</sup> Cancri System|year=2005}}</ref>
According to him, instead of the 2.8-day planet
there is a planet with a mass similar to that of
Neptune in a 261-day orbit (corresponding to 0.77
AU in distance). This analysis has been partially
confirmed in [[November 2007]] - a planet
designated [[55 Cancri f]] with half the mass of [[
Saturn]] was announced in a 260-day orbit, right in
55 Cancri A's [[habitable zone]].<ref>http://www.
sciencedaily.com/releases/2007/11/
071106133058.htm</ref> The planet itself is not
thought to be conducive to life, but hypothetical
moons or [[Trojan planet]]s in principle could
maintain at least microbial life.-->
{{গ্রহছক-৫
| [[৫৫ ক্যানক্রি ই|ই]]
| >০.০৩৪ ± ০.০০৩৬
| ২.৮১৭০৫ ± ০.০০০১
১৭২ ⟶ ৬৬০ নং লাইন:
| ০.০৭ ± ০.০৬
|-
| [[৫৫ ক্যানক্রি বি|বি]]
| >০.৮২৪ ± ০.০০৭
| ১৪.৬৫১৬২ ± ০.০০০৭
১৭৮ ⟶ ৬৬৬ নং লাইন:
| ০.০১৪ ± ০.০০৮
|-
| [[৫৫ ক্যানক্রি সি|সি]]
| >০.১৬৯ ± ০.০০৮
| ৪৩.৯৩ ± ০.০২১
১৮৪ ⟶ ৬৭২ নং লাইন:
| ০.০৮৬ ± ০.০৫২
|-
| [[৫৫ ক্যানক্রি এফ|এফ]]
| >০.১৪৪ ± ০.০৪
| ২৬০ ± ১.১
১৯০ ⟶ ৬৭৮ নং লাইন:
| ০.২ ± ০.২
|-
| [[৫৫ ক্যানক্রি ডি|ডি]]
| >৩.৮৩৫ ± ০.০৮
| ৫২১৮ ± ২৩০
১৯৮ ⟶ ৬৮৬ নং লাইন:
==আরও দেখুন==
* [[নিশ্চিত বহিঃসৌর জাগতিক গ্রহ বিশিষ্ট তারাসমূহের তালিকা]]
* [[
* [[পিএসআর ১২৫৭+১২]]
==তথ্যসূত্র==
২০৬ ⟶ ৬৯৪ নং লাইন:
==বহিঃসংযোগ==
* [http://www.sky-map.org/?ra=8.876611&de=28.
330833&zoom=9&show_grid=1&show_box=1 &box_ra=8.876611&box_de=28.330833 &box_width=50&box_height=50&img_source= SDSS '''SKY-MAP.ORG''' 55 Cancri, SDSS image] * [http://simbad.u-strasbg.fr/sim-id.pl?protocol=
html&Ident=HD+75732 '''SIMBAD''': HD 75732 -- High proper-motion Star] * [http://simbad.u-strasbg.fr/sim-id.pl?protocol=
html&Ident=HD+75732B '''SIMBAD''': HD 75732B -- High proper-motion Star] * [http://starrymirror.com/5thplanetorbitingstar.htm
Astronomers Find Fifth Planet Around 55 Cancri] * [http://exoplanet.eu/star.php?st=55+Cnc '''The
Extrasolar Planets Encyclopaedia''': Notes for star 55 Cnc] * [http://www.solstation.com/stars2/55cnc2.htm
'''SolStation''': 55 Cancri 2] * [http://www.extrasolar.net/startour.asp?
StarCatID=normal&StarID=4 '''Extrasolar Visions''': 55 Cancri] * [http://www.astro.uiuc.edu/~kaler/sow/55cnc.html
55 Cancri] from The Planet Project at the [[ University of Illinois at Urbana-Champaign]] * [http://www.berkeley.edu/news/media/releases/
2004/08/31_neptune.shtml Astronomers searching for distant Earths find two Neptunes]
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