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Unome wrote:

Hopefully I remember this correctly (Click to Show Hidden Text)

dimmer drops faster?

jonboyage wrote:

Unome wrote:

Hopefully I remember this correctly (Click to Show Hidden Text)

dimmer drops faster?

I don't think so :/ (Click to Show Hidden Text)

I have read in the past that the brighter ones drop faster

[quote="Wikipedia - Phillips relationship"]They found that the faster the supernova faded from maximum light, the fainter its peak magnitude was[/quote]

jonboyage wrote:Yeah you were right sorry, I checked online right after I posted just to make sure and I found that the dimmer ones drop faster.
Do you want to ask the next one?

A type Ia supernova is discovered in a distant galaxy. Its maximum apparent magnitude is measured at 18.4. After monitoring the supernova for 15 days, the B band magnitude drops by 1.2.
1. What is the theoretical absolute luminosity of a type Ia supernova originating from a single progenitor?
2. Calculate the distance to the supernova based on this theoretical absolute magnitude.
3. Determine the speed at which the galaxy containing the supernova is receding. Use a Hubble constant of 70 km^-1*Mpc^-1
4. Based on the luminosity decline, determine the actual absolute magnitude of the supernova.
5. Recalculate the distance and recessional velocity based on the actual absolute magnitude.

Unome wrote:

jonboyage wrote:Yeah you were right sorry, I checked online right after I posted just to make sure and I found that the dimmer ones drop faster.
Do you want to ask the next one?

Sure. Here's a tie-in math question. (Click to Show Hidden Text)

A type Ia supernova is discovered in a distant galaxy. Its maximum apparent magnitude is measured at 18.4. After monitoring the supernova for 15 days, the B band magnitude drops by 1.2.
1. What is the theoretical absolute luminosity of a type Ia supernova originating from a single progenitor?
2. Calculate the distance to the supernova based on this theoretical absolute magnitude.
3. Determine the speed at which the galaxy containing the supernova is receding. Use a Hubble constant of 70 km^-1*Mpc^-1
4. Based on the luminosity decline, determine the actual absolute magnitude of the supernova.
5. Recalculate the distance and recessional velocity based on the actual absolute magnitude.

1. -19.3
2. 346.7mpc
3. 24271.6km/s
4. -18.4884
5. 238.6mpc; 16702.4km/s

jonboyage wrote:

Unome wrote:

jonboyage wrote:Yeah you were right sorry, I checked online right after I posted just to make sure and I found that the dimmer ones drop faster.
Do you want to ask the next one?

Sure. Here's a tie-in math question. (Click to Show Hidden Text)

A type Ia supernova is discovered in a distant galaxy. Its maximum apparent magnitude is measured at 18.4. After monitoring the supernova for 15 days, the B band magnitude drops by 1.2.
1. What is the theoretical absolute luminosity of a type Ia supernova originating from a single progenitor?
2. Calculate the distance to the supernova based on this theoretical absolute magnitude.
3. Determine the speed at which the galaxy containing the supernova is receding. Use a Hubble constant of 70 km^-1*Mpc^-1
4. Based on the luminosity decline, determine the actual absolute magnitude of the supernova.
5. Recalculate the distance and recessional velocity based on the actual absolute magnitude.

Answer (Click to Show Hidden Text)

1. -19.3
2. 346.7mpc
3. 24271.6km/s
4. -18.4884
5. 238.6mpc; 16702.4km/s

Bob_117 wrote:

jonboyage wrote:

Unome wrote:

Sure. Here's a tie-in math question. (Click to Show Hidden Text)

A type Ia supernova is discovered in a distant galaxy. Its maximum apparent magnitude is measured at 18.4. After monitoring the supernova for 15 days, the B band magnitude drops by 1.2.
1. What is the theoretical absolute luminosity of a type Ia supernova originating from a single progenitor?
2. Calculate the distance to the supernova based on this theoretical absolute magnitude.
3. Determine the speed at which the galaxy containing the supernova is receding. Use a Hubble constant of 70 km^-1*Mpc^-1
4. Based on the luminosity decline, determine the actual absolute magnitude of the supernova.
5. Recalculate the distance and recessional velocity based on the actual absolute magnitude.

Answer (Click to Show Hidden Text)

1. -19.3
2. 346.7mpc
3. 24271.6km/s
4. -18.4884
5. 238.6mpc; 16702.4km/s

Sorry for jumping in but I have a question. How did you calculate the absolute magnitude in question 4? I've looked up luminosity decline rate and a couple other things and I haven't been able to find anything. Thanks in advance.

jonboyage wrote:

Bob_117 wrote:

jonboyage wrote:

Answer (Click to Show Hidden Text)

1. -19.3
2. 346.7mpc
3. 24271.6km/s
4. -18.4884
5. 238.6mpc; 16702.4km/s

Sorry for jumping in but I have a question. How did you calculate the absolute magnitude in question 4? I've looked up luminosity decline rate and a couple other things and I haven't been able to find anything. Thanks in advance.

I simply used the formula for the Philips relationship which you can easily find the Wikipedia page for. The formula is this: M_max(B) = -21.726 + 2.698Δm_15(B). This formula is very specific to the scenario given here: after 15 days, the B-band magnitude drops by 1.2. Hope that helps!