Mt. Hamilton Observing Information

UNIVERSITY OF CALIFORNIA OBSERVATORIES / LICK OBSERVATORY

The following images and spectra were made with the Nickel 1-m telescope of the Lick Observatory by participants in the October 1999 session of the teacher-training workshop "What do Astronomers Do?," given at Lick on Mount Hamilton.

The Ring Nebula, M57, in H-alpha
The planetary nebula M57, a remnant of a dying star, imaged on a CCD through a filter which only transmits the color of light given off by the Hydrogen-alpha at 6563 Angstroms. The true color of this image would be deep red.
The Ring Nebula, M57, in OIII
The planetary nebula M57 imaged through a filter which only transmits the color of light given off by doubly-ionized Oxygen at 5007 angstroms. The true color of this image is green.

Above: A spectrum of the Ring Nebula, M57, from about 4000-9000 Angstromsr.
A spectrum showing the emission lines from the planetary nebula M57. The bright lines near the center--some seen as two distinct spots--are from the nebula. The vertical lines extending from top to bottom are from the night sky. The thinnest horizontal line at center is the continuous spectrum of the white dwarf star at the nebula's center. The true color of the spectrum would go from below violet at the left, through blue, green, yellow, and orange, to red and beyond on the right.
Below: A plot of the spectrum.
The plot is of the M57 spectrum in the upper image. Note that though wavelength is along the X-axis, it is labeled with the CCD's column numbers, rather than in a unit of wavelength (as it properly should be). The actual wavelength scale is approximately 4000-9000 Angstroms, left to right on the plot.
The strong peak near column 520 is from doubly-ionized Oxygen. The much weaker peak near column 790 is from Hydrogen alpha.

The emission nebula IC1546, in the light of Hydrogen-alpha
This nebula is region of tenuous gas out of which stars are being formed. Here it is imaged on a CCD through the same Hydrogen-alpha filter used on M57 (a very different kind of nebula). As before, the true color is deep red. Note that the regular, curving bands are not actually in the nebula, but are an artifact of the imaging process--a consequence of optical interference on the CCD.
IC1546 in the light of doubly-ionized Oxygen
Here the nebula has been imaged through the same Oxygen-III filter used with M57. The true color of this image is green.

Above: A spectrum of the emission nebula IC5146, from about 4000-9000 Angstromsr.
In this spectrum, all the lines extend from top to bottom. Some originate in the nebula, some in the background sky. As in the previous plot, the X-axis, though representing wavelength, is labeled with the CCD's column numbers. The actual wavelength scale is approximately 4000-9000 Angstroms, left to right on the plot.
Below: A plot of the spectrum.
Again, as in the M57 plot, OIII and H-alpha are at about columns 520 and 790 respectively, but their relative strengths are reversed.

The following images and spectra were made with the Nickel 1-m telescope of the Lick Observatory by participants in the October 1999 session of the teacher-training workshop "What do Astronomers Do?," given at Lick on Mount Hamilton.




The Ring Nebula, M57, in H-alpha The planetary nebula M57, a remnant of a dying star, imaged on a CCD through a filter which only transmits the color of light given off by the Hydrogen-alpha at 6563 Angstroms. The true color of this image would be deep red.	The Ring Nebula, M57, in OIII The planetary nebula M57 imaged through a filter which only transmits the color of light given off by doubly-ionized Oxygen at 5007 angstroms. The true color of this image is green.





Above: A spectrum of the Ring Nebula, M57, from about 4000-9000 Angstromsr. A spectrum showing the emission lines from the planetary nebula M57. The bright lines near the center--some seen as two distinct spots--are from the nebula. The vertical lines extending from top to bottom are from the night sky. The thinnest horizontal line at center is the continuous spectrum of the white dwarf star at the nebula's center. The true color of the spectrum would go from below violet at the left, through blue, green, yellow, and orange, to red and beyond on the right. Below: A plot of the spectrum. The plot is of the M57 spectrum in the upper image. Note that though wavelength is along the X-axis, it is labeled with the CCD's column numbers, rather than in a unit of wavelength (as it properly should be). The actual wavelength scale is approximately 4000-9000 Angstroms, left to right on the plot. The strong peak near column 520 is from doubly-ionized Oxygen. The much weaker peak near column 790 is from Hydrogen alpha.




The emission nebula IC1546, in the light of Hydrogen-alpha This nebula is region of tenuous gas out of which stars are being formed. Here it is imaged on a CCD through the same Hydrogen-alpha filter used on M57 (a very different kind of nebula). As before, the true color is deep red. Note that the regular, curving bands are not actually in the nebula, but are an artifact of the imaging process--a consequence of optical interference on the CCD.	IC1546 in the light of doubly-ionized Oxygen Here the nebula has been imaged through the same Oxygen-III filter used with M57. The true color of this image is green.





Above: A spectrum of the emission nebula IC5146, from about 4000-9000 Angstromsr. In this spectrum, all the lines extend from top to bottom. Some originate in the nebula, some in the background sky. As in the previous plot, the X-axis, though representing wavelength, is labeled with the CCD's column numbers. The actual wavelength scale is approximately 4000-9000 Angstroms, left to right on the plot. Below: A plot of the spectrum. Again, as in the M57 plot, OIII and H-alpha are at about columns 520 and 790 respectively, but their relative strengths are reversed.