Utente:Amarvudol/HD 84406
| HD 84406 | |
|---|---|
 | |
| Classe spettrale | A:K0 III / B:F0 V / C:F8 |
| Distanza dal Sole | 258,5±2 al |
| Costellazione | Orsa Maggiore |
| Coordinate | |
| (all'epoca J2000) | |
| Ascensione retta | 09h 47m 30.55s |
| Declinazione | +63° 14′ 52.09″ |
| Dati fisici | |
| Raggio medio | A:16 / B:1,3 / C:1? R⊙ |
| Massa | A:4 / B:1,7 / C:? M⊙
|
| Velocità di rotazione | A: ~17 km/s |
| Temperatura superficiale | |
| Luminosità | A: 300 / B:15 / C:1-2? L⊙
|
| Indice di colore (B-V) | A: 1,07 |
| Dati osservativi | |
| Magnitudine app. | +1,79 (A:1,87 / B:4,81 / C:7,12) |
| Magnitudine ass. | A:−1,10 / B:1,83 / C:4,22[1] |
| Parallasse | 26,38 ± 0,53 mas |
| Moto proprio | AR: −136,46,66 mas/anno Dec: −35,25 mas/anno |
| Velocità radiale | −9 km/s |
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HD 84406, is a star approximately 258.5 light-years away in the constellation of Ursa Major. The star is a spectral type G star and has a high proper motion.[2]
On 4 February 2022, HD 84406 was the first star viewed by the James Webb Space Telescope. Relatively isolated, the star will be used to test and align the focus of the telescope's 18 primary mirrors.[3][4][5][6] On 11 February 2022. The New York Times reported that "first light" images of HD 84406 from JWST were released - as well as a related NASA alignment video (2/11/2022; 3:00).[7]
Gallery
[modifica | modifica wikitesto]-
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18 images of same target star HD 84406 by the 18 unfocused mirror segments. -
Phase 1 interim image, annotated with the related mirror segments that took each image. -
18 unfocused images of same target star HD 84406. -
Phase 1 annotated completion image of HD 84406. -
Phase 2 completion, showing "before and after" effects of segment alignment. -
Phase 3 completion, showing 18 segments "stacked" as a single image of HD 84406.
References
[modifica | modifica wikitesto]- ^ Bruce W. Carney, David F. Gray, David Yong, David W. Latham, Nadine Manset, Rachel Zelman, John B. Laird, Rotation and Macroturbulence in Metal-Poor Field Red Giant and Red Horizontal Branch Stars, in The Astronomical Journal, vol. 135, n. 3, marzo 2008, pp. 892–906, Bibcode:2008AJ....135..892C, DOI:10.1088/0004-6256/135/3/892.
- ^ HD 84406, in SIMBAD, Centre de données astronomiques de Strasbourg. URL consultato il 25 gennaio 2022.
- ^ George Dvorsky, Webb Space Telescope Successfully Sees Its First Glimmer of Light - HD 84406 will go down in history as the first star spotted by the $10 billion space telescope., in Gizmodo, 4 February 2022. URL consultato il 4 February 2022.
- ^ Alan Boyle, Webb Telescope fires thrusters to settle in at destination, a million miles from Earth, su geekwire.com, 24 January 2022.
- ^ Alise Fisher, The Webb Team Looks Back on Successful Deployments, su blogs.nasa.gov, 27 January 2022.
- ^ Abby Lee Hood, The James Webb Space Telescope Just Detected Its First Signal - We're Watching The Future Unfold In Real Time,, in Futurism.com, 6 February 2022. URL consultato il 6 February 2022.
- ^ Dennis Overbye, James Webb Telescope Sends Home a Selfie and 18 Images of Starlight - The spacecraft recorded a series of images of a target star that will be used to help its mirrors prepare for scientific research., in The New York Times, 11 February 2022. URL consultato il 12 February 2022.
Template:James Webb Space Telescope Template:Stars of Ursa Major