5 Astraea
Template:About Template:Short description {{#invoke:infobox|infoboxTemplate | class = vcard | titleclass = fn org | title = 5 Astraea | image = {{#invoke:InfoboxImage|InfoboxImage|image=5Astraea (Lightcurve Inversion).png|upright={{#if:||1.1}}|alt=}} | caption = Lightcurve-based 3D-model of Astraea | headerstyle = {{#if:#D6D6D6|background-color:#D6D6D6|background-color:#E0CCFF}} | labelstyle = max-width:{{#if:||11em}}; | autoheaders = y
| header1 = Discovery<ref name="MPC-object" />
| label2 = Discovered by | data2 = K. L. Hencke | label3 = Discovery site | data3 = Driesen Obs. | label4 = Discovery date | data4 = 8 December 1845 | label5 = Template:Longitem | data5 =
| header10 = {{#if:|Designations|Designations}}
| label11 = Template:Longitem
| data11 = (5) Astraea
| label12 = Pronunciation
| data12 = Template:IPAc-en<ref>Template:Cite dictionary</ref>
| label13 = Template:Longitem
| data13 = Astraea Template:Small<ref name="springer" />
| label14 = Template:Longitem
| data14 = 1969 SE
| label15 = Template:Longitem
| data15 = main-belt<ref name="MPC-object" /><ref name="jpldata" />Template:·Template:Small
Astraea<ref name="AstDys-object" />
| label16 = Adjectives
| data16 = Astraean
| label17 = Symbol
| data17 = The historic planetary symbol for 5 Astraea (historical astronomical), The modern astrological symbol for 5 Astraea (modern astrological)
| header20 = Orbital characteristics{{#ifeq:|yes| (barycentric)}}<ref name="jpldata" />
| data21 = | data22 = {{#if:23 March 2018 (JD 2458200.5) |Epoch 23 March 2018 (JD 2458200.5)}} | data23 = {{#if:0 | Uncertainty parameter 0}} | label24 = Observation arc | data24 = 171.93 yr (62,799 d) | label25 = Earliest precovery date | data25 = | label26 = {{#switch:{{{apsis}}} |apsis|gee|barion|center|centre|(apsis)=Apo{{{apsis}}} |Ap{{#if:|{{{apsis}}}|helion}}}} | data26 = 3.0659 AU | label27 = Peri{{#if:|{{{apsis}}}|helion}} | data27 = 2.0810 AU | label28 = Peri{{#if:|{{{apsis}}}|apsis}} | data28 = | label29 = {{#switch:{{{apsis}}} |helion|astron=Ap{{{apsis}}} |Apo{{#if:|{{{apsis}}}|apsis}}}} | data29 = | label30 = Periastron | data30 = | label31 = Apoastron | data31 = | label32 = Template:Longitem | data32 = 2.5735 AU | label33 = Template:Longitem | data33 = | label34 = Eccentricity | data34 = 0.1914 | label35 = Template:Longitem | data35 = Template:Cvt 4.13 yr (1,508 d) | label36 = Template:Longitem | data36 = | label37 = Template:Longitem | data37 = | label38 = Template:Longitem | data38 = 186.83° | label39 = Template:Longitem | data39 = Template:Deg2DMS / day | label40 = Inclination | data40 = 5.3677° | label41 = Template:Longitem | data41 = | label42 = Template:Longitem | data42 = 141.58° | label43 = Template:Longitem | data43 = | label44 = Template:Longitem | data44 = | label45 = Template:Longitem | data45 = 358.75° | label46 = Template:Nowrap | data46 = | label47 = Satellite of | data47 = | label48 = Group | data48 = | label49 = {{#switch: |yes|true=Satellites |Known satellites}} | data49 = | label50 = Star | data50 = | label51 = Earth MOID | data51 = | label52 = Mercury MOID | data52 = | label53 = Venus MOID | data53 = | label54 = Mars MOID | data54 = | label55 = Jupiter MOID | data55 = | label56 = Saturn MOID | data56 = | label57 = Uranus MOID | data57 = | label58 = Neptune MOID | data58 = | label59 = TJupiter | data59 =
| header60 = Proper orbital elements<ref name=Astraea-POE>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
| label61 = Template:Longitem
| data61 = {{#if:2.5761849 |2.5761849 AU}}
| label62 = Template:Longitem
| data62 = 0.1980486
| label63 = Template:Longitem
| data63 = 4.5118628°
| label64 = Template:Longitem
| data64 = {{#if:87.046396 |87.046396 degTemplate:\yr}}
| label65 = Template:Longitem
| data65 = {{#if:87.046396|{{#expr:360/87.046396 round 5}} yr
({{#expr:365.25*360/87.046396 round 3}} d) }}
| label66 = Template:Longitem
| data66 = {{#if:52.210903|52.210903 arcsecTemplate:\yr }}
| label67 = Template:Longitem
| data67 = {{#if:−57.357951|−57.357951 arcsecTemplate:\yr}}
| header70 = Template:Anchor{{#if:yes| Physical characteristics|Physical characteristics}}
| label71 = Dimensions | data71 = Template:Val<ref name=Lopez-Gonzales>Template:Cite journal</ref> | label72 = Template:Longitem | data72 = 125 km<ref name=Lopez-Gonzales /> | label73 = Template:Longitem | data73 = | label74 = Template:Longitem | data74 = | label75 = Template:Longitem | data75 = | label76 = Flattening | data76 = | label77 = Circumference | data77 = | label78 = Template:Longitem | data78 = 48 900 km2Template:Efn | label79 = Volume | data79 = 920 000 km3Template:Efn | label80 = Mass | data80 = Template:Nwr | label81 = Template:Longitem | data81 = 3.501 ± 0.420/0.581 g/cm3<ref name="FiengaEtAl2020"/>Template:Efn | label82 = Template:Longitem | data82 = | label83 = Template:Longitem | data83 = | label84 = Template:Longitem | data84 = | label85 = Template:Longitem | data85 = 0.700 04 d (16.801 h)<ref name=Lopez-Gonzales /> | label86 = Template:Longitem | data86 = | label87 = Template:Longitem | data87 = 6.49 m/sTemplate:Efn | label88 = Template:Longitem | data88 = | label89 = Template:Longitem | data89 = 115°/310° ± 5° | label90 = Template:Longitem | data90 = 55° ± 5° | label91 = Template:Longitem | data91 = | label92 = Template:Longitem | data92 = | label93 = {{#if:yes |Template:Longitem |Albedo}} | data93 = 0.227<ref name="SIMPS" /> | label94 = Temperature | data94 =
| data100 = {{#if:|
{{#if:|}}{{#if:|}}{{#if:|}}{{#if:|}}Surface temp. | min | mean | max |
---|---|---|---|
{{{temp_name1}}} | |||
{{{temp_name2}}} | |||
{{{temp_name3}}} | |||
{{{temp_name4}}} |
}}
| label101 = Surface absorbed dose rate | data101 = | label102 = Surface equivalent dose rate | data102 = | label103 = Template:Longitem | data103 = S | label104 = Template:Longitem | data104 = | label105 = Template:Longitem | data105 = 8.74 to 12.89 | label106 = Template:Longitem | data106 = 6.85 | label107 = Template:Longitem | data107 = 0.15" to 0.041"
| header110 = Atmosphere
| label111 = Template:Longitem | data111 = | label112 = Template:Longitem | data112 = | label113 = Composition by volume | data113 =
| below = {{#if:||Template:Reflist }}
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5 Astraea (Template:IPAc-en) is an asteroid in the asteroid belt. This object is orbiting the Sun at a distance of Template:Convert with a period of Template:Cvt and an orbital eccentricity of 0.19. The orbital plane is inclined at an angle of 5.37° to the plane of the ecliptic. It is spinning with a period of 16.8 h. The surface of Astraea is highly reflective and its composition is probably a mixture of nickel–iron with silicates of magnesium and iron. It is an S-type asteroid in the Tholen classification system.<ref name="jpldata" />
Discovery and nameEdit
Astraea was the fifth asteroid discovered, on 8 December 1845, by Karl Ludwig Hencke and named for Astraea, a Greek goddess of justice named after the stars. It was his first of two asteroid discoveries. The second was 6 Hebe. A German amateur astronomer and post office headmaster, Hencke was looking for 4 Vesta when he stumbled on Astraea. The King of Prussia awarded him an annual pension of 1200 marks for the discovery.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Hencke's symbol for Astraea is an inverted anchor, in the pipeline for Unicode 17.0 as U+1F778 (File:Astraea symbol (fixed width).svg),<ref name=astunicode>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=pipeline>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> though given Astraea's role with justice and precision, it is perhaps a stylized set of scales, or a typographic substitute for one.<ref name=berlin-1845> Template:Cite book</ref><ref name=schmadel>Template:Cite book</ref> This symbol is no longer used. The astrological symbol is a percent sign, encoded specifically at U+2BD9 ⯙:<ref name="L216080">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> it is simply shift-5 on the keyboard, because Astraea was the fifth asteroid discovered.<ref name=astunicode/> The modern astronomical symbol is a simple encircled 5 (⑤).
For 38 years after the discovery of the fourth known asteroid, Vesta, in 1807, no further asteroids were discovered.<ref name=18planets>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> After the discovery of Astraea, 8 more were discovered in the following 5 years, and 24 were found in the 5 years after that. The discovery of Astraea proved to be the starting point for the eventual demotion of the four original asteroids (which were regarded as planets at the time)<ref name=18planets/> to their current status, as it became apparent that these four were only the largest of a new type of celestial body with thousands of members.
CharacteristicsEdit
Photometry indicates prograde rotation, that the north pole points in the direction of right ascension 115° or 310° and declination 55°, with a 5° uncertainty.<ref name=Lopez-Gonzales /> This gives an axial tilt of about 33°.Template:Cn With an apparent magnitude of 8.7 (on a favorable opposition on 15 February 2016), it is only the seventeenth-brightest main-belt asteroid, and fainter than, for example, 192 Nausikaa or even 324 Bamberga (at rare near-perihelion oppositions).
An stellar occultation on 6 June 2008 allowed Astraea's diameter to be estimated; it was found to be Template:Nowrap.<ref name="Ďurech2011">Template:Cite journal</ref>
See alsoEdit
NotesEdit
<references group="lower-alpha" />
ReferencesEdit
External linksEdit
- 2 Telescope images of 5 Astraea
- MNRAS 7 (1846) 27
- Physical characteristics of (5) Astraea at the Small Bodies Data Ferret
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- Dictionary of Minor Planet Names, Google books
- Template:AstDys
- Template:JPL small body