1 / 13

Astronomical Photometry

Astronomical Photometry. How to get from there to here. Stars , sky , observing , telescope, filters , detector, noise, reduction, graphing. Apparent magnitude of a star will depend on: Luminosity Distance ( F is flux) Stuff in between it and us (extinction; reddening). Stars.

sophie
Download Presentation

Astronomical Photometry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Astronomical Photometry How to get from there to here Stars, sky, observing, telescope, filters, detector, noise, reduction, graphing

  2. Apparent magnitude of a star will depend on: Luminosity Distance (F is flux) Stuff in between it and us (extinction; reddening) Stars Definition of magnitude (visual wavelengths): Definition of “color” of a star:

  3. Getting the effective temperature of a star using UBVRI FILTERS Color of star will also depend slightly on chemical composition (metal-rich vs metal-poor)

  4. Filters B V R B V R

  5. We always use filters. Original filter set was for a photometer, not CCDs. Telescopes may have different sets of filters (width and peak of band passes may differ, response may differ); may need to TRANSFORM magnitudes to a standard system.

  6. Reddening (“de-bluing”) Antares/Rho Ophiuchus Region

  7. Color Excess Slope of the reddening line for stars earlier than A0: Find star here Extrapolate there For cooler stars, must use spectroscopy.

  8. Sky Bad, badder, baddest!

  9. Z

  10. Observations CV’s

  11. FIG. 1.Light curves are presented for the six variable stars. Points represent observed data in B (filled circles), V (asterisks), and I (open circles). The dotted curves represent the best-fitting template to the observed data. The vertical axis in each panel spans 2 mag.

More Related