Delta Pavonis

Delta Pavonis
HR-designaatio	7665
HD-designaatio	190248
Fyysiset ominaisuudet
Näennäinen kirkkaus	+3,56 mv
Absoluuttinen kirkkaus	+4,62 Mv
Valovoima	bolometrinen L=1.27 , näkyvän alueen Lv=1.2 aurinkoa
Spektriluokka	G5-8 V-IV
Väri-indeksi	B-V 0.76 ja U-B 0.45
Lämpötila	5,609±8 K
Massa	1.07±0.01 M☉
Säde	1.197±0.016 R☉
Pyörimisnopeus	Kerran 21.4±9.3 päivässä, v sin i 0.32 m/s
Metallipitoisuus	2,34 aurinkoa ,kun [Fe/H] on 0.371±0.008 dex
Ikä	6.10+0.26−0.25 miljardia vuotta
Astrometriset ominaisuudet
Tähdistö	Riikinkukko
Rektaskensio (J2000)	20h 08m 43,6084s
Deklinaatio (J2000)	−66° 10′ 55,446″
Etäisyys	19,89 valovuotta
Parallaksi	163,78 ± 0,65 mas
Säteisnopeus	-21,7±0,9 km/s
Ominaisliike	RA: 1210,50; Dec.: −1130,27 mas/v
	Näkyy leveysasteiden 24° N ; ja 90° S välillä.
	Infobox OK

Delta Pavonis (δ Pav / δ Pavonis) on tähti Riikinkukon tähtikuviossa. Tähti ei näy Suomessa.

Se muistuttaa jonkin verran aurinkoa, mutta on sitä kirkkaampi, painavampi, vanhempi ja metallirikkaampi.^[1] ^[2]

Tähti on spektriluokkaansa nähden kirkas ja siksi "vanha" tähti, joka on kirkastumassa pois pääsarjasta. Tähti saattaa olla kehittymässä alijättiläiseksi tai olla se jo.

Epäilty planeetta

Delta Pavonisilla epäillään olevan planeetta. Havaintojen mukaan yli 69 Maan massainen planeetta saatata kiertää Delta Pavonista yli 11.1 AU päässä siitä.^[3]

Lähteet

↑ Nils Mustelin, Elämää maailmankaikkeudessa, sivu 218
↑ Adam D Rains, Michael J Ireland, Timothy R White, Luca Casagrande, I Karovicova, Precision angular diameters for 16 southern stars with VLTI/PIONIER, Monthly Notices of the Royal Astronomical Society, Volume 493, Issue 2, April 2020, Pages 2377–2394, https://doi.org/10.1093/mnras/staa282
↑ @article{Laliotis_2023, doi = {10.3847/1538-3881/acc067}, url = {https://doi.org/10.3847/1538-3881/acc067}, year = {2023}, month = {mar}, publisher = {The American Astronomical Society}, volume = {165}, number = {4}, pages = {176}, author = {Laliotis, Katherine and Burt, Jennifer A. and Mamajek, Eric E. and Li, Zhexing and Perdelwitz, Volker and Zhao, Jinglin and Butler, R. Paul and Holden, Bradford and Rosenthal, Lee and Fulton, B. J. and Feng, Fabo and Kane, Stephen R. and Bailey, Jeremy and Carter, Brad and Crane, Jeffrey D. and Furlan, Elise and Gnilka, Crystal L. and Howell, Steve B. and Laughlin, Gregory and Shectman, Stephen A. and Teske, Johanna K. and Tinney, C. G. and Vogt, Steven S. and Wang, Sharon Xuesong and Wittenmyer, Robert A.}, title = {Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions* }, journal = {The Astronomical Journal}, abstract = {Directly imaging temperate rocky planets orbiting nearby, Sun-like stars with a 6 m class IR/O/UV space telescope, recently dubbed the Habitable Worlds Observatory, is a high-priority goal of the Astro2020 Decadal Survey. To prepare for future direct imaging (DI) surveys, the list of potential targets should be thoroughly vetted to maximize efficiency and scientific yield. We present an analysis of archival radial velocity data for southern stars from the NASA/NSF Extreme Precision Radial Velocity (EPRV) Working Group’s list of high-priority target stars for future DI missions (drawn from the HabEx, LUVOIR, and Starshade Rendezvous studies). For each star, we constrain the region of companion mass and period parameter space we are already sensitive to based on the observational baseline, sampling, and precision of the archival radial velocity (RV) data. Additionally, for some of the targets, we report new estimates of magnetic activity cycle periods, rotation periods, improved orbital parameters for previously known exoplanets, and new candidate planet signals that require further vetting or observations to confirm. Our results show that for many of these stars we are not yet sensitive to even Saturn-mass planets in the habitable zone, let alone smaller planets, highlighting the need for future EPRV vetting efforts before the launch of a DI mission. We present evidence that the candidate temperate super-Earth exoplanet HD 85512b is most likely due to the star’s rotation, and report an RV acceleration for δ Pav that supports the existence of a distant giant planet previously inferred from astrometry.} }

Riikinkukon tähdistö (Pavo) » luettelo tähdistä, luokka

Tähdet	α Pav, β Pav, δ Pav, η Pav, ε Pav, ζ Pav, γ Pav, λ Pav, π Pav, ξ Pav, κ Pav, ν Pav, φ¹ Pav, ρ Pav, ο Pav, φ² Pav, ω Pav, υ Pav, μ² Pav, σ Pav, ι Pav, SX Pav, θ Pav, μ¹ Pav, τ Pav, Y Pav
Eksoplaneetat	φ² Pav b

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[1] Nils Mustelin, Elämää maailmankaikkeudessa, sivu 218

[2] Adam D Rains, Michael J Ireland, Timothy R White, Luca Casagrande, I Karovicova, Precision angular diameters for 16 southern stars with VLTI/PIONIER, Monthly Notices of the Royal Astronomical Society, Volume 493, Issue 2, April 2020, Pages 2377–2394, https://doi.org/10.1093/mnras/staa282

[3] @article{Laliotis_2023, doi = {10.3847/1538-3881/acc067}, url = {https://doi.org/10.3847/1538-3881/acc067}, year = {2023}, month = {mar}, publisher = {The American Astronomical Society}, volume = {165}, number = {4}, pages = {176}, author = {Laliotis, Katherine and Burt, Jennifer A. and Mamajek, Eric E. and Li, Zhexing and Perdelwitz, Volker and Zhao, Jinglin and Butler, R. Paul and Holden, Bradford and Rosenthal, Lee and Fulton, B. J. and Feng, Fabo and Kane, Stephen R. and Bailey, Jeremy and Carter, Brad and Crane, Jeffrey D. and Furlan, Elise and Gnilka, Crystal L. and Howell, Steve B. and Laughlin, Gregory and Shectman, Stephen A. and Teske, Johanna K. and Tinney, C. G. and Vogt, Steven S. and Wang, Sharon Xuesong and Wittenmyer, Robert A.}, title = {Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions* }, journal = {The Astronomical Journal}, abstract = {Directly imaging temperate rocky planets orbiting nearby, Sun-like stars with a 6 m class IR/O/UV space telescope, recently dubbed the Habitable Worlds Observatory, is a high-priority goal of the Astro2020 Decadal Survey. To prepare for future direct imaging (DI) surveys, the list of potential targets should be thoroughly vetted to maximize efficiency and scientific yield. We present an analysis of archival radial velocity data for southern stars from the NASA/NSF Extreme Precision Radial Velocity (EPRV) Working Group’s list of high-priority target stars for future DI missions (drawn from the HabEx, LUVOIR, and Starshade Rendezvous studies). For each star, we constrain the region of companion mass and period parameter space we are already sensitive to based on the observational baseline, sampling, and precision of the archival radial velocity (RV) data. Additionally, for some of the targets, we report new estimates of magnetic activity cycle periods, rotation periods, improved orbital parameters for previously known exoplanets, and new candidate planet signals that require further vetting or observations to confirm. Our results show that for many of these stars we are not yet sensitive to even Saturn-mass planets in the habitable zone, let alone smaller planets, highlighting the need for future EPRV vetting efforts before the launch of a DI mission. We present evidence that the candidate temperate super-Earth exoplanet HD 85512b is most likely due to the star’s rotation, and report an RV acceleration for δ Pav that supports the existence of a distant giant planet previously inferred from astrometry.} }

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