DD Microscopii
{{Short description|Star in the constellation Microscopium}}
{{Starbox begin
| name = DD Microscopii
}}
{{Starbox image
| image = 250px
| caption = A visual band light curve for DD Microscopii, plotted from ASAS-SN data
}}
{{Starbox observe
| constell = Microscopium
}}
{{Starbox character
| class = K2 III or K5/M0 IIIe
| variable = Z And
}}
{{Starbox astrometry
| prop_mo_ra = −10.080
| prop_mo_dec = −2.035
| parallax = 0.1072
| p_error = 0.0205
| absmag_v =
}}
{{Starbox orbit
| primary = yellow giant
| name = White dwarf
| period =
| period_unitless = {{val|1442|ul=days|fmt=commas}}
| eccentricity = 0.22
| periastron = 2,445,560
| periarg_primary = 261
| k1 = 4.6
| k2 =
}}
{{Starbox detail
| component1 = yellow giant
| luminosity =
| age_gyr =
}}
{{Starbox catalog
| names = {{odlist|CD = −43°14304|GSC = 07973-00869|V = DD Mic}}
}}
{{Starbox reference
| Simbad = DD+Mic
}}
{{Starbox end}}
DD Microscopii, also known as CD−43°14304, is a binary star system in the constellation Microscopium. The system has a combined average apparent magnitude around 11, making it readily visible in telescopes but not to the naked eye. It is thought to be at a distance of one or two thousand parsecs, although parallax measurements place the system at a distance of around 30,000 light years.
It is a symbiotic star system composed of an orange giant with a class of either K2 III or K5/M0 IIIe. Both stellar classifications of the primary indicate a red giant, but one has a regular spectrum while the other shows an evolved star with the characteristics of a K5 and M0 giant star plus emission lines in its spectrum. The secondary is a white dwarf in close orbit, ionizing the stellar wind of the larger star.{{Citation needed|date=June 2022}} The giant star and white dwarf both take about 4 years to orbit each other.
The primary has an enlarged radius of {{val|103|ul=solar radius}} and an effective temperature of {{val|3941|ul=K|fmt=commas}}, giving a red hue when viewed through a telescope. DD Microscopii is extremely metal deficient, with an iron abundance only 12% of the Sun, and spins leisurely with a projected rotational velocity lower than {{val|3|ul=km/s}}. The star system has its origin in the galactic halo of the Milky Way as indicated by the high galactic latitude. DD Microscopii is cataloged as a Z Andromedae variable, a type of symbiotic binary with occasional outbursts. It fluctuates between magnitudes 11.0 and 11.7 over a span of almost 400 days.
References
{{reflist||refs=
{{Cite Gaia EDR3|6485077605356668032 }}
{{Cite simbad|title = DD Mic|access-date = March 25, 2015}}
}}
{{Stars of Microscopium}}
{{DEFAULTSORT:DD Microscopii}}