Archivo de imágenes de Hubble
Estrellas variables cefeidas en la galaxia espiral NGC 3021
This is a Hubble Space Telescope photo of the spiral galaxy NGC 3021. This was one of several hosts of recent Type Ia supernovae observed by astronomers to refine the measure of the universe's expansion rate, called the Hubble constant. Hubble made precise measurements of Cepheid...
- Fecha
- Jan 1, 2009
- Misión
- Hubble Space Telescope
- ID de archivo
- hubblesite-images-2009-08-2487-image
This is a Hubble Space Telescope photo of the spiral galaxy NGC 3021. This was one of several hosts of recent Type Ia supernovae observed by astronomers to refine the measure of the universe's expansion rate, called the Hubble constant. Hubble made precise measurements of Cepheid variable stars in the galaxy, highlighted by green circles in the four inset boxes. These stars pulsate at a rate that is matched closely to their intrinsic brightness. This makes them ideal for measuring intergalactic distances. The Cepheids are used to calibrate an even brighter milepost marker that can be used over greater distances, a Type Ia supernova. The supernova was observed in the galaxy in 1995. The images in the boxes were taken with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).
Credits
NASA, ESA, and A. Riess (STScI/JHU)Detalles de la imagen
| About The Object | |
|---|---|
| Object Name | NGC 3021 |
| Object Description | Spiral Galaxy |
| R.A. Position | 09h 50m 57s.13 |
| Dec. Position | +33° 33' 12".71 |
| Constellation | Leo Minor |
| Distance | 92 million light-years (28 megaparsecs) |
| Dimensions | This image is roughly 1.5 arcminutes (41,000 light-years or 12.5 kiloparsecs) wide. |
| About The Data | |
| Data Description | Data from several HST proposals were used for this science. These include: , , , , and , PI: A. Riess (STScI/JHU). Data specific to observations of NGC 3021 are from HST proposals and PI: A. Riess (STScI/JHU). The science team includes: A. Riess (STScI/JHU), L. Macri (Texas A&M University), S. Casertano and M. Sosey (STScI), H. Lampeitl (STScI/University of Portsmouth, UK), H. Ferguson (STScI), A. Filippenko (University of California, Berkeley), S. Jha (Rutgers University), W. Li and R. Chornock (University of California, Berkeley), and D. Sarkar (University of California, Irvine). |
| Instrument | HST>NICMOS and HST>ACS/WFC |
| Exposure Dates | November 2005 - November 2006, Exposure Time: 23.8 hours (ACS), and October 2006 - March 2007, Exposure Time: 18.4 hours (NICMOS) |
| Filters | ACS: F555W (V) and F814W (I) NICMOS: F160W (H-band) |
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