1 Supernova Q 1a) The left part of Figure 1 slows a Hubble Space Telescope (HST) image of the Type II Supernova 1987a (SN1987a)

Question

1 Supernova

Q 1a) The left part of Figure 1 slows a Hubble Space Telescope (HST) image of the Type II Supernova 1987a (SN1987a). The major axis of the bright central ring has an angular size of 1.66”. The right part of Figure 1 shows observations from the International Ultraviolet Explorer (IUE) mission obtained after the supernova. The observations revealed narrow NIII emission limes that were first detected 80 days after the supernova reaching a maximum intensity 420 days later. It is believed this emission was due to radiation that was reprocessed by material associated with the bright ring at some distance from the supernova. Given these observations, what is the distance to SN1987a in parsecs? Clearly state any assumptions.

Q1b. SN1987a reached a peak apparent magnitude of +2.9. Estimate the main-sequence life-time of the sun if the Sun's time-averaged Luminosity was equal to the peak output of SN1987a. Express your answer in Gyr.

Q1c. A neutron star was predicted to be farmed by SN1987a. If the star had an initial rotation period of 1-monuth, what would be the rotation period of the neutron star? Assume (incorrectly) a constant mass of 2 M for the entire lifetime of the star.

Q1d. A Type da supernova results the destruction of a white dwarf and the release of an enormous amount of energy over a few seconds peaking at an absolute magnitude of -19.3. Compare observed energy output to the total nuclear energy potential of a degenerate white dwarf just prior to nova. Given your answer, would a Type la supernova produce any type of remnant?

Intensity 600

400

200

0

Days since explosion 0 200 400 600 800

Figure 1: The image to the left shows the remnant of SN1987a based on observations from HST. The central ring has a major axis angular size of 1.66”. The figure to the right shows the observed intensity (in units of 10^-22 W cm^-2) of NIII emission lines after the supernova.

1 Supernova

Q 1a) The left part of Figure 1 slows a Hubble Space Telescope (HST) image of the Type II Supernova 1987a (SN1987a). The major axis of the bright central ring has an angular size of 1.66”. The right part of Figure 1 shows observations from the International Ultraviolet Explorer (IUE) mission obtained after the supernova. The observations revealed narrow NIII emission limes that were first detected 80 days after the supernova reaching a maximum intensity 420 days later. It is believed this emission was due to radiation that was reprocessed by material associated with the bright ring at some distance from the supernova. Given these observations, what is the distance to SN1987a in parsecs? Clearly state any assumptions.

Q1b. SN1987a reached a peak apparent magnitude of +2.9. Estimate the main-sequence life-time of the sun if the Sun's time-averaged Luminosity was equal to the peak output of SN1987a. Express your answer in Gyr.

Q1c. A neutron star was predicted to be farmed by SN1987a. If the star had an initial rotation period of 1-monuth, what would be the rotation period of the neutron star? Assume (incorrectly) a constant mass of 2 M for the entire lifetime of the star.

Q1d. A Type da supernova results the destruction of a white dwarf and the release of an enormous amount of energy over a few seconds peaking at an absolute magnitude of -19.3. Compare observed energy output to the total nuclear energy potential of a degenerate white dwarf just prior to nova. Given your answer, would a Type la supernova produce any type of remnant?

Intensity 600

400

200

0

Days since explosion 0 200 400 600 800

Figure 1: The image to the left shows the remnant of SN1987a based on observations from HST. The central ring has a major axis angular size of 1.66”. The figure to the right shows the observed intensity (in units of 10^-22 W cm^-2) of NIII emission lines after the supernova.