Discussion Overview
The discussion revolves around the challenges of performing a photometric analysis of the M5 globular cluster, specifically addressing the issues of extinction and reddening that affect the color-magnitude diagram (CMD) produced from images taken in the B, V, and R bands. Participants explore methods to calculate the extinction value E(B-V) necessary for accurate distance measurements using the luminosity of the tip of the RGB.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant expresses difficulty in calculating the extinction value E(B-V) necessary for their analysis of M5.
- Another participant suggests that the issue may stem from an instrument problem and inquires if additional images have been taken.
- A third participant points out that the NASA Extragalactic Database (NED) provides extinction values for M5 and recommends checking the relevant notes and papers for appropriateness.
- The original poster acknowledges the usefulness of the NED resource and expresses gratitude for the assistance received.
Areas of Agreement / Disagreement
Participants do not reach a consensus on the cause of the red and faint CMD, as one suggests a potential instrument issue while another provides a resource for calculating extinction. The discussion remains open-ended regarding the best approach to resolve the extinction and reddening effects.
Contextual Notes
Limitations include potential dependencies on the accuracy of the extinction values provided by NED and the need for further validation of the instrument used for imaging.