65 Ursae Majoris

{{short description|Star system in the constellation Ursa Major}}

{{Starbox begin|name=65 Ursae Majoris}}

{{Starbox image

| image=

{{Location mark

|image=Ursa Major constellation map.svg|alt=|float=center|width=280

|label=|position=right

|mark=Red circle.svg|mark_width=8|mark_link=65 UMa

|x=420|y=623

}}

|caption=Location of 65 Ursae Majoris (circled)

}}

{{Starbox observe 2s

|epoch=J2000

|constell=Ursa Major

|component1=65 UMa ABC

|ra1={{RA|11|55|05.74925}}{{cite journal|title=Validation of the new Hipparcos reduction|url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL|author1=van Leeuwen, F.|display-authors=etal|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|date=2007|arxiv=0708.1752|bibcode=2007A&A...474..653V|doi=10.1051/0004-6361:20078357|s2cid = 18759600}}

|dec1={{DEC|+46|28|36.6408}}

|appmag_v1=+6.54{{cite journal|bibcode=1964ApJ...139.1105T|title=A UBV Study of 94 Wide Visual Binaries|journal=Astrophysical Journal|volume=139|page=1105|author1=Tolbert, C. R.|year=1964|doi=10.1086/147852|doi-access=free}} {{nowrap begin}}(A/B/C = 6.7 / 8.5 / 8.32){{cite journal|bibcode=1997A&AS..124...75T|title=MSC - a catalogue of physical multiple stars|journal=Astronomy & Astrophysics Supplement Series|volume=124|pages=75–84|last1=Tokovinin|first1=A. A.|year=1997|doi=10.1051/aas:1997181|doi-access=free}}{{nowrap end}}

|component2=65 UMa D

|ra2={{RA|11|55|11.33152}}

|dec2={{DEC|+46|28|11.2150}}

|appmag_v2=+6.965{{cite journal|title=The Tycho-2 catalogue of the 2.5 million brightest stars|author1=Høg, E.|display-authors=etal|date=2000|journal=Astronomy and Astrophysics|volume=355|pages=L27–L30|bibcode=2000A&A...355L..27H}}

}}

{{Starbox character

|component1=65 UMa ABC

|class=A7 / A7 / A3 / ? / ?

|b-v=+0.11

|u-b=+0.08

|variable=Algol

|component2=65 UMa D

|class2=A0p{{cite book|chapter=Abundance and stratification analysis of the CP star HD 103498|author1=Pandey, Chhavi P.|author2=Shulyak, Denis V.|author3=Ryabchikova, Tanya|author4=Kochukhov, Oleg|date=2012|title=International Workshop on Stellar Spectral Libraries |series=ASI Conference Series |volume=6 |page=225 |bibcode=2012ASInC...6..225P}}
See also {{cite journal |doi=10.1111/j.1365-2966.2011.19281.x|doi-access=free |title=Abundance and stratification analysis of the chemically peculiar star HD 103498 |date=2011 |last1=Pandey |first1=Chhavi P. |last2=Shulyak |first2=Denis V. |last3=Ryabchikova |first3=Tanya |last4=Kochukhov |first4=Oleg |journal=Monthly Notices of the Royal Astronomical Society |volume=417 |issue=1 |pages=444–452 |arxiv=1106.3727 |bibcode=2011MNRAS.417..444P }}

|b-v2=+0.02

|u-b2=+0.01

}}

{{Starbox astrometry

|component1=65 UMa ABC

|radial_v={{val|-3.90|4.4}}{{cite journal|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|author=Gontcharov, G. A.|date=2006|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|bibcode=2006AstL...32..759G|doi=10.1134/S1063773706110065|arxiv=1606.08053|s2cid=119231169}}

|prop_mo_ra=10.41

|prop_mo_dec=2.38

|parallax=4.72

|p_error=0.58

|parallax_footnote=

|absmag_v=−0.05{{cite journal

| title=XHIP: An extended hipparcos compilation

| last1=Anderson | first1=E. | last2=Francis | first2=Ch.

| journal=Astronomy Letters

| volume=38 | issue=5 | pages=331 | year=2012

| bibcode=2012AstL...38..331A | arxiv=1108.4971

| doi=10.1134/S1063773712050015 | s2cid=119257644 }}

|component2=65 UMa D

|radial_v2={{val|-7.00|3.7}}{{cite journal|title=Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations|author1=Kharchenko, N. V.|display-authors=etal|journal=Astronomische Nachrichten|volume=328|issue=9|page=889|date=2007|bibcode=2007AN....328..889K|doi=10.1002/asna.200710776|arxiv=0705.0878|s2cid=119323941}}

|prop_mo_ra2=11.82

|prop_mo_dec2=0.39

|parallax2=3.37

|p_error2=0.56

|parallax_footnote2=

|absmag_v2=−0.1{{cite journal

| bibcode=1998A&A...336..953G

| title=The HR-diagram from HIPPARCOS data. Absolute magnitudes and kinematics of BP - AP stars

| journal=Astronomy and Astrophysics

| volume=336

| pages=953

| last1=Gomez

| first1=A. E.

| last2=Luri

| first2=X.

| last3=Grenier

| first3=S.

| last4=Figueras

| first4=F.

| last5=North

| first5=P.

| last6=Royer

| first6=F.

| last7=Torra

| first7=J.

| last8=Mennessier

| first8=M. O.

| year=1998

}}

}}

{{Starbox orbit

|reference={{cite journal|title=Unique sextuple system: 65 Ursae Majoris|author1=Zasche, P.|author2=Uhlář, R.|author3=Šlechta, M.|author4=Wolf, M.|author5=Harmanec, P.|author6=Nemravová, J. A.|author7=Korčáková, D.|journal=Astronomy & Astrophysics|volume=542|pages=A78|date=2012|bibcode=2012A&A...542A..78Z|doi=10.1051/0004-6361/201219134|arxiv=1207.0651|s2cid=56328797}}

|primary=65 UMa Aa1

|name=65 UMa Aa2

|period_unitless={{val|1.73043|u=days}}

|axis_unitless=

|periastron=

|node=

|periarg=

|inclination={{val|86.5|0.2}}

|eccentricity=

|k1={{val|133.3|4.2}}

|k2={{val|135.7|4.2}}

}}

{{Starbox orbit

|reference=

|primary=65 UMa Aa

|name=65 UMa Ab

|period_unitless={{val|641.5|16.7}}

|axis_unitless=

|periastron=

|node=

|periarg=

|inclination=47

|eccentricity={{val|0.169|0.048}}

|k1=13.7

|k2={{val|19.9|2.7}}

}}

{{Starbox orbit

|reference=

|primary=65 UMa A

|name=65 UMa B

|period={{val|118.209|0.690}}

|axis_unitless={{val|208.2|9.7|ul=mas}}

|periastron={{val|2447516.9|126.8}}

|node={{val|92.1|4.2}}

|periarg={{val|202.7|1.3}}

|inclination={{val|38.1|2.4}}

|eccentricity={{val|0.504|0.006}}

}}

{{Starbox detail

|component1=65 UMa Aa1

|mass={{val|1.74|0.06}}

|temperature=8,000

|radius={{val|1.86|0.08}}

|component2=65 UMa Aa2

|mass2={{val|1.71|0.06}}

|temperature2={{val|7948|20|fmt=commas}}

|radius2={{val|1.81|0.08}}

}}

{{Starbox detail|no_heading=y

|component1=65 UMa Ab

|mass={{val|2.4|0.4}}

}}

{{Starbox detail|no_heading=y

|component1=65 UMa B

|mass={{val|2.4|2.0}}

}}

{{Starbox detail|no_heading=y

|component1=65 UMa C

|mass=2.01

}}

{{Starbox detail|no_heading=y

|component1=65 UMa D

|mass=2.31{{cite journal |bibcode=2019AstBu..74...66G |title=On Properties of Main Sequence Magnetic Stars |last1=Glagolevskij |first1=Yu. V. |journal=Astrophysical Bulletin |year=2019 |volume=74 |issue=1 |page=66 |doi=10.1134/S1990341319010073 |s2cid=149900274 }}{{nowrap|(3.02 + 1.64)}}

|radius=2.93

|temperature=8,600

|luminosity=79

|gravity=3.85

|age_myr=525

}}

{{Starbox catalog

|names=65 UMa, ADS 8347, CCDM J11551+4629

|component1=65 UMa ABC

|names1=DN UMa, BD+47°1913, HD 103483, HIP 58112, HR 4560, SAO 43945

|component2=65 UMa D

|names2=BD+47°1914, HD 103498, HIP 58117, HR 4561, SAO 43946

}}

{{Starbox reference

|Simbad2=DN+UMa|sn2=65 UMa AB

|Simbad3=ADS+8347+C|sn3=65 UMa C

|Simbad4=HR+4561|sn4=65 UMa D

}}

{{Starbox end}}

65 Ursae Majoris, abbreviated as 65 UMa, is a star system in the constellation of Ursa Major. With a combined apparent magnitude of about 6.5, it is at the limit of human eyesight and is just barely visible to the naked eye in ideal conditions. It is about 760 light years away from Earth.

65 Ursae Majoris is a sextuple star system. It contains six stars in a hierarchical orbit where each star orbits its inner stars. Such systems are uncommon, with only a few sextuple stars known. Higher-multiplicity star systems are uncommon because they are less stable than their simpler counterparts, and often decay into smaller systems.