4197 Morpheus

Template:Short description Template:Use dmy dates {{#invoke:infobox|infoboxTemplate | class = vcard | titleclass = fn org | title = 4197 Morpheus | image = {{#invoke:InfoboxImage|InfoboxImage|image=|upright={{#if:||1.1}}|alt=}} | caption = | headerstyle = {{#if:#FFC2E0|background-color:#FFC2E0|background-color:#E0CCFF}} | labelstyle = max-width:{{#if:||11em}}; | autoheaders = y

| header1 = Discovery<ref name="jpldata" />

| header10 = {{#if:|Designations|Designations}}

| header20 = Orbital characteristics{{#ifeq:|yes| (barycentric)}}<ref name="jpldata" />

| data21 = | data22 = {{#if:4 September 2017 (JD 2458000.5) |Epoch 4 September 2017 (JD 2458000.5)}} | data23 = {{#if:0 | Uncertainty parameter 0}} | label24 = Observation arc | data24 = 61.98 yr (22,639 days) | label25 = Earliest precovery date | data25 = 3 September 1954 | label26 = {{#switch:{{{apsis}}} |apsis|gee|barion|center|centre|(apsis)=Apo{{{apsis}}} |Ap{{#if:|{{{apsis}}}|helion}}}} | data26 = 4.0690 AU | label27 = Peri{{#if:|{{{apsis}}}|helion}} | data27 = 0.5246 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 = 2.2968 AU | label33 = Template:Longitem | data33 = | label34 = Eccentricity | data34 = 0.7716 | label35 = Template:Longitem | data35 = 3.48 yr (1,271 days) | label36 = Template:Longitem | data36 = | label37 = Template:Longitem | data37 = | label38 = Template:Longitem | data38 = 339.88° | label39 = Template:Longitem | data39 = Template:Deg2DMS / day | label40 = Inclination | data40 = 12.577° | label41 = Template:Longitem | data41 = | label42 = Template:Longitem | data42 = 7.1844° | label43 = Template:Longitem | data43 = | label44 = Template:Longitem | data44 = | label45 = Template:Longitem | data45 = 122.40° | 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 = 0.0987 AUTemplate:·38.5 LD | 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 = T_Jupiter | data59 =

| header60 = Proper orbital elements

| label61 = Template:Longitem | data61 = {{#if: |{{{p_semimajor}}} AU}} | label62 = Template:Longitem | data62 = | label63 = Template:Longitem | data63 = | label64 = Template:Longitem | data64 = {{#if: |{{{p_mean_motion}}} deg Template:\yr}} | label65 = Template:Longitem | data65 = {{#if:|{{#expr:360/1 round 5}} yr
({{#expr:365.25*360/1 round 3}} d) }} | label66 = Template:Longitem | data66 = {{#if:|{{{perihelion_rate}}} arcsec Template:\yr }} | label67 = Template:Longitem | data67 = {{#if:|{{{node_rate}}} arcsec Template:\yr}}

| header70 = Template:Anchor{{#if:yes| Physical characteristics|Physical characteristics}}

| label71 = Dimensions | data71 = | label72 = Template:Longitem | data72 = 1.8 km Template:Small<ref name="jpldata" />
Template:Val km Template:Small<ref name="Harris-1998a" />
2.98 km Template:Small<ref name="lcdb" />
Template:Val km<ref name="Pravec-2012b" />
Template:Val km<ref name="WISE" /> | label73 = Template:Longitem | data73 = | label74 = Template:Longitem | data74 = | label75 = Template:Longitem | data75 = | label76 = Flattening | data76 = | label77 = Circumference | data77 = | label78 = Template:Longitem | data78 = | label79 = Volume | data79 = | label80 = Mass | data80 = | label81 = Template:Longitem | data81 = | label82 = Template:Longitem | data82 = | label83 = Template:Longitem | data83 = | label84 = Template:Longitem | data84 = | label85 = Template:Longitem | data85 = Template:Val h<ref name="Prokofeva-2001" />
Template:Val h<ref name="Pravec-2000a" />
Template:Val h<ref name="Galad-2004" />
Template:Val h<ref name="Wisniewski-1997" />
Template:Val h<ref name="Hoffmann-1993a" /> | label86 = Template:Longitem | data86 = | label87 = Template:Longitem | data87 = | label88 = Template:Longitem | data88 = | label89 = Template:Longitem | data89 = | label90 = Template:Longitem | data90 = | label91 = Template:Longitem | data91 = | label92 = Template:Longitem | data92 = | label93 = {{#if:yes |Template:Longitem |Albedo}} | data93 = Template:Val<ref name="lcdb" /><ref name="Pravec-2012b" />
Template:Val<ref name="WISE" />
Template:Val<ref name="Harris-1998a" /> | label94 = Temperature | data94 =

| data100 = {{#if:|

Surface temp.	min	mean	max
{{{temp_name1}}}
{{{temp_name2}}}
{{{temp_name3}}}
{{{temp_name4}}}

}}

| header110 = Atmosphere

| below = {{#if:||Template:Reflist }}

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4197 Morpheus, provisional designation Template:Mp, is a highly eccentric asteroid and near-Earth object of the Apollo group, approximately 3 kilometers in diameter. It was discovered on 11 October 1982, by American astronomers Eleanor Helin and Eugene Shoemaker at Palomar Observatory in California, United States. The asteroid was later named for Morpheus from Greek mythology.<ref name="MPC-Morpheus" />

Orbit and classificationEdit

Morpheus orbits the Sun at a distance of 0.5–4.1 AU once every 3 years and 6 months (1,271 days). Its orbit has an eccentricity of 0.77 and an inclination of 13° with respect to the ecliptic.<ref name="jpldata" /> Due to this elongated orbit, the asteroid is both, a Mars-crosser and a Venus-crosser.

It has a minimum orbit intersection distance with Earth of Template:Convert, which corresponds to 38.5 lunar distances.<ref name="jpldata" />

A first precovery was taken at the discovering observatory in 1954, extending the body's observation arc by 28 years prior to its official discovery observation.<ref name="MPC-Morpheus" />

Physical characteristicsEdit

On the SMASS taxonomic scheme, Morpheus is classified as a stony Sq sub-type, which transitions from the common S-type to the rather rare Q-type asteroids.<ref name="jpldata" />

Diameter and albedoEdit

In the 1990s, Tom Gehrels gave a first diameter estimate for Morpheus of 1.8 kilometers.<ref name="jpldata" /> According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), it measures 3.043 kilometers in diameter and its surface has an albedo of 0.276.<ref name="WISE" /> In 2012, a revision of the published WISE-data by Petr Pravec gave a diameter of 2.981 kilometers and an albedo of 0.2389.<ref name="Pravec-2012b" /> The Collaborative Asteroid Lightcurve Link adopts the revised WISE-data and takes a diameter of 2.98 kilometers with an absolute magnitude of 14.8.<ref name="lcdb" />

Rotation and shapeEdit

In 1996, a rotational lightcurve was obtained by Czech astronomer Petr Pravec at the Ondřejov Observatory during the body's close approach to Earth within 0.1 AU. It gave a well-defined rotation period of Template:Val hours with a brightness variation of 0.49 magnitude (Template:Small).<ref name="Pravec-2000a" />

At the same time, astronomers at the Goldstone Observatory analysed Morpheus using radar delay-Doppler imaging. The resultant images are not very clear, but they show that the body has a roughly triangular shape, and a 3-hour rotation period.Template:Citation needed

Seven years later, during the asteroid's next close approach in 2003, Morpheus was observed for five nights by Slovak astronomer Adrián Galád at the Modra Observatory. Lightcurve analysis showed a concurring period of Template:Val hours and an amplitude of 0.4 in magnitude (Template:Small).<ref name="Galad-2004" />

NamingEdit

This minor planet was named after Morpheus from Greek mythology. He is a god of dreams who appears in the poem Metamorphoses written by the Roman poet Ovid. He is capable to imitate any human form and to appear in dreams.

The approved naming citation was published by the Minor Planet Center on 5 January 2015 (Template:Small).<ref name="MPC-Circulars-Archive" />

ReferencesEdit

Template:Reflist

External linksEdit

Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Template:NeoDys
Template:ESA-SSA
Template:JPL small body

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