Supernovas

June 30, 2019

Lookout Observatory: Another Supernova Photographed

Dear Lookout Observers,

One interesting compact cluster of 5 galaxies, known as Hickson 68, is about 110 million light years distant, and it is shown in the first image attached. Each galaxy is labeled with its number in the New General Catalog (NGC). Other more distant galaxies can be seen as tiny ovals or smudges, but they are not part of this gravitationally connected cluster This image was taken on June 12, 2018.

On May 1, 2019, a supernova explosion in the galaxy NGC 5353 was first discovered by professional astronomers with a telescope in Hawaii. On May 15 my childhood friend and fellow amateur astrophotographer Fritz Kleinhans told me about this new supernova, but because of cloudy weather and other commitments, I wasn’t free to obtain an image of this supernova until June 7. In the second image attached this new star is indicated by the green arrow. A supernova is what occurs when a star destructively blows up much like trillions of hydrogen bombs going off all at once. This is an evolutionary stage that some stars go through, ending their life as a normal star. In a matter of a few days this single star became one fifteenth as bright as all the billions of stars in the NGC 5353 galaxy put together! It seems to have reached its peak brightness of about 14^th magnitude around May 15, and by the time I got my image it had faded to about 15^th magnitude. It will continue fading over the next year or so until it disappears again.

(“Magnitude” is a measure of the apparent total brightness of a celestial object, and the larger the number, the fainter the object. So, for example, the brightest stars in the night sky are about 1^st magnitude and the faintest stars most people can see in a reasonably dark sky are about 6^th mag. The faintest stars that can be seen in an amateur’s 10-inch diameter telescope are about 14^th mag., but using photography with my 11-inch, I can image stars fainter than 20^th mag. Each unit change in magnitude represents a factor of about 2.5, so a 15^th mag. star is about 2 and ½ times fainter than a 14^th mag. star.)

The third image is a slightly larger field around the Hickson 68 group of galaxies. At the far left is another spiral galaxy, NGC 5371, which appears larger than any in the Hickson 68 group. It is approximately the same distance as the Hickson group, so it may be gravitationally connected to the group of 5, and it actually is larger than any of the galaxies in that group. It is slightly smaller than our own Milky Way Galaxy.

The fourth image, showing the nearby galaxy M101, is exactly at the same scale as the third image. That is, it covers exactly the same amount of sky – about ½ degree high and ¾ degree across, so the full moon could just fit into this picture. M101 looks so huge because it is 5 times closer than the galaxies in the 3^rd image, but it is probably only slightly larger than NGC 5371. Although M101 is roughly the same size as our Milky Way Galaxy, it contains twice as many stars. One of its stars exploded as a supernova back in 2011, but it has faded away by now. I reported on this event in a Lookout Observatory report on July 3, 2012. In this current photo you can see some of the outer reaches of the arms extending to the left (east) and up (north). The small pinkish areas are regions of active star formation with lots of hydrogen gas. At the far left of the picture, about 1/3 of the way down, is a so-called dwarf galaxy, NGC 5477. It is a companion to M101, just as our galaxy has many dwarf galaxies gravitationally connected to us, as described in a Lookout Observatory bulletin on October 18, 2018. This image shows stars and tiny distant galaxies down to about 21^st magnitude.

May you have sunny days in your life and clear skies at night,

Carter, (sometime) resident astronomer,

Lookout Observatory

P.S. My apologies to those who responded to my last Lookout Observatory report and didn’t get a response back from me. I have recently had so many commitments that I couldn’t respond to everyone. I will try to do better.

Click on any image to get a closer look

A cluster of 5 galaxies known as Hickson 68

A supernova explosion in the galaxy NGC 5353

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Hickson 68 group of galaxies & another spiral galaxy, NGC 5371

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Galaxy M101 & dwarf galaxy, NGC 5477

May 19, 2017

Galaxies, Supernovas 0

Massive Explosion noted by Lookout Observatory

Dear Friends,

An explosion that began just about a week ago continues to pour out energy at approximately ten thousand million million (10 to the 16^th power) times the output of our sun. Luckily for us it is not near enough to vaporize us. In fact, it is a million million times as far from us as the sun is, so it is only a perfectly safe, faint point of light. This is a newly discovered supernova – exploding star – in the Fireworks Galaxy (also known as NGC 6946), about 22 million light years away from our own Milky Way Galaxy.

This exploding star, now known as SN 2017eaw, is what is known as a Type II supernova. That is, it was probably a red giant star at least 10 times as massive as our sun that eventually lost its ability to produce nuclear fusion, leading to sudden collapse under its own massive gravitation, raising it’s core temperature to 10,000 times the sun’s core temperature, resulting in an unimaginably immense explosion where bits of the star are moving at up to 1/3 the speed of light. In destroying itself the star brightens immensely in a matter of seconds, then gradually fades over months and years. This supernova was discovered by Patrick Wiggins, a Utah amateur astronomer who dedicates many hours to searching for these “new stars.”

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Fireworks Galaxy (pre 2017)

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Fireworks Galaxy + supernova SN 2017eaw

February 27, 2014

Supernovas 0

Another Massive Nuclear Explosion you didn’t hear about in mainstream news

An extremely dense, old star known as a white dwarf star exploded on January 14, 2014, but wasn’t noticed until a week later. Luckily this occurred in a galaxy known as M82, about 12 million light years away. If it had occurred in our own Milky Way galaxy anywhere near the sun, we would already have been obliterated.

This exploding star, known as a supernova, designated SN 2014J, is a type 1a supernova, a kind that helps astronomers measure the size and expansion rate of the universe. The galaxy it is located in, M82, is an irregular galaxy, not the more common spiral type. It has lots of dust and hydrogen gas and active star formation occurring in its center. The first image is a picture of M82 I took in June of 2012

This galaxy can be seen in a modest telescope near the Big Dipper. This photo was taken well before the explosion.

The second image is a picture of M82 I took February 23, 2014:

The new star is at the point where the two red lines would intersect. As you can see, it is brighter than anything else in the whole galaxy, thus representing a massive amount of energy output. To give you a sense of the apparent size of this galaxy, it’s length would fit about 6 times across the full moon. So it appears much smaller, and about 100 million times fainter that the full moon.

Many people think the stars never change, but supernovas are an exception. They can appear almost instantly, sometimes outshining all the other stars in a galaxy combined, then gradually fade over several years.

Keep looking up,

Carter Mehl,

(Sometime) Resident Astronomer,

Lookout Observatory

Click on any image to get a closer look

M82 June 2012

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M82 February 2014

July 3, 2012

Supernovas 0

Huge explosion seen from Lookout Observatory!

Dear Friend of Lookout Observatory,

OK, I admit the headline is misleading. It is true that a massive explosion was observed from Lookout Observatory (LO), but it happened about 22 million light years away. (A light year is the distance light travels in a year, a little more than 6 trillion miles.) And it happened back in August of 2011. But it has never been reported to you before, so let me explain.

This exciting — at least to astronomers — event happened in a relatively nearby galaxy with the designation M101. M101 is visible from dark, non-light-poluted skies in a small telescope as a small fuzzy patch in the sky above the handle of the Big Dipper. The first picture attached (Series122) shows it as I was able to photograph it on the night of June 16, 2012. You can see the many spiral arms leading out from the bright core of the galaxy. Billions of stars blend together to make the light that we see in this spiral pattern. Most of the individual stars that you see in this picture are forground stars in our own Milky Way galaxy that we have to look past in order to see M101 22 million light years distant. That is about 200 times the diameter of our Milky Way, so if you imagine the Milky Way as the size of a standard CD or DVD, M101 would be the size of a salad plate 75 feet away.

But what makes this galaxy especially interesting is that on August 24, 2011, Palomar Observatory in Southern California discovered a star in this galaxy blowing itself up in a massive thermonuclear explosion — something called a Type 1a supernova. A supernova is what occurs when a star destructively blows up much like trillions of hydrogen bombs going off all at once. Over a period of a few days this star increased it’s luminosity to 5 billion times that of the Sun. On August 23 it was not visible. On August 24 it was first discovered. On August 27 my childhood friend, Dr. Fritz Kleinhans, a professional physicist and astronomer, emailed me at L.O., and I was able to get photographs on August27, 28, and 30. It was rapidly brightening then, and it continued to brighten until mid-September. Since then it has been fading so that it is now visible only in a fairly large telescope. The second photograph attached (Series87) shows the supernova as it was on August 28. I have put a blue circle around the star. You can see that it was already brighter than most of the foreground stars that are thousands of times closer, being nearby in our own galaxy. If you check back to the first photograph, taken just a few weeks ago, you will see that the supernova has by now faded to just a faint blue star. If you enlarge both pictures and can look at them side-by-side, it is easy to see the change. (There are some tiny red streaks in the second photo. They are defects. Ignore them.)

This is the brightest supernova that has been seen in over 20 years, and it is one of the earliest ever discoveries in the cycle of a supernova. It was first detected just about 11 hours after it first exploded! This type of supernova can be used by astronomers as a “standard candle” to judge how far away it is based on its brightness, thus helping to determine more accurately the size of the universe. By the way, this was the very first astronomically significant event to be observed at Lookout Observatory, and you have now shared in it. I hope you enjoyed it.

As always, if you don’t have an interest in this sort of thing, please reply to this email and let me know to remove you from this list. No hard feelings. There is too much email going around, and we all need to be selective. On the other hand, if you know people who would like to be added to this distribution list, they can email me and ask to be added.

Keep looking up,

Carter Mehl,

(sometime) Resident Astronomer,

Lookout Observatory

Supernova June 16 2012

Supernova Aug 28 2011