Comparison of Pressure Broadening Effects in Markab and Deneb
Deneb |
Markab |
|
| Radius (Ro) | 203 |
4.7 |
| Temperature (K) | 8525 |
9765 |
| Spectral Type | A2 Ia |
A0IV |
| Rotational Velocity (km/s) | 20 |
125 |
Note that Markab rotates 6 times faster than Deneb and has an average density almost 10 000 times as much! Deneb has an extremely rarefied atmosphere - this means that its atmosphere has a much lower pressure than Markab's. The result is that the spectral lines in Deneb's spectrum are MUCH narrower.
|
|
|
| Figure 1: Spectra of Deneb and Markab with accompanying set of line profiles in the Hα region. (The King's University Observatory images) |