Astronomical Stargazer Thread

[JamesR]

My imaging is finished for the year. Everything is packed up for my move so I feel safe sharing this. It's all the images I took in 2019.

 

From top left to bottom right:

M42, Moon during Jan Eclipse, Jupiter, Saturn, Horse head and flame nebula, M82 (bodes galaxy & M81 (Cigar galaxy)

Milky way, M101 (pinwheel galaxy), M3 glob cluster, Moon in RGB, Moon in Mono

M16, M8, Pickering's Triangle, Elephant Trunks nebula.

 

 

 

Larger resolution:

 

https://i.imgur.com/NR4QxkG.jpg

 

[Tim Sielbeck]

Great shots, James!

[Mobius]

Does anyone have Space Engine?

[JamesR]

Great shots, James!

 

Thanks!

[DB]

Wow. To catch the planets above a city at night.

Should be easy in California, going forward.

[Ivanhoe]

[Corinthian]

[Panzermann]

Nice!

[BansheeOne]

Meanwhile, off the shoulder of Orion:

 

A giant star is acting strange, and astronomers are buzzing

The red giant Betelgeuse is the dimmest seen in years, prompting some speculation that the star is about to explode. Here's what we know.

By Nadia Drake

 

PUBLISHED December 26, 2019

 

The constellation Orion is one of the most recognizable patterns in the night sky, visible around the world. But if you’ve looked at Orion recently and thought something seemed off, you’re not wrong: The giant red star Betelgeuse, which marks the hunter’s right shoulder, is the dimmest it’s been in almost a century.

 

Normally, Betelgeuse is among the 10 brightest stars in the sky. However, the red giant began dimming in October, and by mid-December, the star had faded so much it wasn’t even in the top 20, Villanova University’s Edward Guinan reported in an Astronomer’s Telegram.

 

“Now the outline of Orion is noticeably different with Betelgeuse so faint,” he says.

 

To be clear, dimming alone isn’t all that odd for a star like Betelgeuse. It’s what’s known as a variable star, and its shifts in brightness have been closely studied for decades. However, it is unusual for one of the sky’s most prominent points of light to fade so noticeably, prompting scientists to consider the possibility that something more exciting could be about to happen: Betelgeuse might explode and die, briefly blazing brighter than the full moon before vanishing from our night sky forever.

 

Huge, red stars like Betelgeuse live fast and die violently, exploding in stellar events called supernovae that are visible across vast distances. So, while Betelgeuse is a relatively young star—only about 8.5 million years old—astronomers know that it is nearing the end of its life.

 

“The biggest question now is when it will explode in a supernova,” UC Berkeley’s Sarafina Nance, who studies Betelgeuse and stellar explosions, said on Twitter. “Disclaimer: I don't think it's going to explode any time soon,” she added during an interview with National Geographic. “But I am excited [for] when it does.”

 

[...]

 

https://www.nationalgeographic.com/science/2019/12/betelgeuse-is-acting-strange-astronomers-are-buzzing-about-supernova/

[Panzermann]

What? Mercury is closer?

 

 

 

 

 

2 Mar 2019 in Commentary & Reviews

Venus is not Earth’s closest neighbor

Calculations and simulations confirm that on average, Mercury is the nearest planet to Earth—and to every other planet in the solar system.

Tom Stockman

Quick: Which planet is closest to Earth? Ask an astronomer or a search engine, and you’ll probably hear that though the situation changes frequently, Venus is the closest when averaged over time. Several educational websites, such as The Planets and Space Dictionary, publish the distance between each pair of planets, and they all show that Venus is nearest to Earth on average. They’re all wrong. NASA literature even tells us Venus is “our closest planetary neighbor,” which is true if we are talking about which planet has the closest approach to Earth but not if we want to know which planet is closest on average.

As it turns out, by some phenomenon of carelessness, ambiguity, or groupthink, science popularizers have disseminated information based on a flawed assumption about the average distance between planets. Using a mathematical method that we devised, we determine that when averaged over time, Earth’s nearest neighbor is in fact Mercury.

That correction is relevant to more than just Earth’s neighbors. The solution can be generalized to include any two bodies in roughly circular, concentric, and coplanar orbits. By using a more accurate method for estimating the average distance between two orbiting bodies, we find that this distance is proportional to the relative radius of the inner orbit. In other words, Mercury is closer to Earth, on average, than Venus is because it orbits the Sun more closely. Further, Mercury is the closest neighbor, on average, to each of the other seven planets in the solar system.

Simple but wrong

To calculate the average distance between two planets, The Planets and other websites assume the orbits are coplanar and subtract the average radius of the inner orbit, r1, from the average radius of the outer orbit, r2. The distance between Earth (1 astronomical unit from the Sun) and Venus (0.72 AU) comes out to 0.28 AU. The table at the bottom of the article shows the calculated distance between each pair of planets using that method.

Although it feels intuitive that the average distance between every point on two concentric ellipses would be the difference in their radii, in reality that difference determines only the average distance of the ellipses’ closest points. Indeed, when Earth and Venus are at their closest approach, their separation is roughly 0.28 AU—no other planet gets nearer to Earth. But just as often, the two planets are at their most distant, when Venus is on the side of the Sun opposite Earth, 1.72 AU away. We can improve the flawed calculation by averaging the distances of closest and farthest approach (resulting in an average distance of 1 AU between Earth and Venus), but finding the true solution requires a bit more effort.

A better approach

To more accurately capture the average distance between planets, we devised the point-circle method. The PCM treats the orbits of two objects as circular, concentric, and coplanar. For our solar system, that’s a pretty reasonable assumption: The eight planets have an average orbital inclination of 2.6° ± 2.2°, and the average eccentricity is 0.06 ± 0.06. An object in a circular orbit maintains constant velocity, which means that over a sufficiently long period, it is equally likely to be in any position in that orbit. We consider a planet’s position at any given time as a uniform probabilistic distribution around a circle defined by the average orbital radius, as shown in figure 1a. The average distance between two planets can therefore be described as the average distance of every point on the circle c2, defined by r2, to every point on the circle c1, defined by r1.

(...)

​

read the whole thing with graphs and stuff: https://physicstoday.scitation.org/do/10.1063/PT.6.3.20190312a/full/

for the reading impaired there is a video:

I really like how he happily talks about his findings and how he did it. You can really hear the joy of science.

Edited January 25, 2020 by Panzermann

[Mobius]

 

What? Mercury is closer?

 

 

 

 

 

2 Mar 2019 in Commentary & Reviews

Venus is not Earth’s closest neighbor

Calculations and simulations confirm that on average, Mercury is the nearest planet to Earth—and to every other planet in the solar system.

Tom Stockman

Quick: Which planet is closest to Earth? Ask an astronomer or a search engine, and you’ll probably hear that though the situation changes frequently, Venus is the closest when averaged over time. Several educational websites, such as The Planets and Space Dictionary, publish the distance between each pair of planets, and they all show that Venus is nearest to Earth on average. They’re all wrong. NASA literature even tells us Venus is “our closest planetary neighbor,” which is true if we are talking about which planet has the closest approach to Earth but not if we want to know which planet is closest on average.

As it turns out, by some phenomenon of carelessness, ambiguity, or groupthink, science popularizers have disseminated information based on a flawed assumption about the average distance between planets. Using a mathematical method that we devised, we determine that when averaged over time, Earth’s nearest neighbor is in fact Mercury.

That correction is relevant to more than just Earth’s neighbors. The solution can be generalized to include any two bodies in roughly circular, concentric, and coplanar orbits. By using a more accurate method for estimating the average distance between two orbiting bodies, we find that this distance is proportional to the relative radius of the inner orbit. In other words, Mercury is closer to Earth, on average, than Venus is because it orbits the Sun more closely. Further, Mercury is the closest neighbor, on average, to each of the other seven planets in the solar system.

Simple but wrong

To calculate the average distance between two planets, The Planets and other websites assume the orbits are coplanar and subtract the average radius of the inner orbit, r1, from the average radius of the outer orbit, r2. The distance between Earth (1 astronomical unit from the Sun) and Venus (0.72 AU) comes out to 0.28 AU. The table at the bottom of the article shows the calculated distance between each pair of planets using that method.

Although it feels intuitive that the average distance between every point on two concentric ellipses would be the difference in their radii, in reality that difference determines only the average distance of the ellipses’ closest points. Indeed, when Earth and Venus are at their closest approach, their separation is roughly 0.28 AU—no other planet gets nearer to Earth. But just as often, the two planets are at their most distant, when Venus is on the side of the Sun opposite Earth, 1.72 AU away. We can improve the flawed calculation by averaging the distances of closest and farthest approach (resulting in an average distance of 1 AU between Earth and Venus), but finding the true solution requires a bit more effort.

A better approach

To more accurately capture the average distance between planets, we devised the point-circle method. The PCM treats the orbits of two objects as circular, concentric, and coplanar. For our solar system, that’s a pretty reasonable assumption: The eight planets have an average orbital inclination of 2.6° ± 2.2°, and the average eccentricity is 0.06 ± 0.06. An object in a circular orbit maintains constant velocity, which means that over a sufficiently long period, it is equally likely to be in any position in that orbit. We consider a planet’s position at any given time as a uniform probabilistic distribution around a circle defined by the average orbital radius, as shown in figure 1a. The average distance between two planets can therefore be described as the average distance of every point on the circle c2, defined by r2, to every point on the circle c1, defined by r1.

(...)

​

read the whole thing with graphs and stuff: https://physicstoday.scitation.org/do/10.1063/PT.6.3.20190312a/full/

for the reading impaired there is a video:

I really like how he happily talks about his findings and how he did it. You can really hear the joy of science.

 

I understand the theory but if he is going to go through the theoretical by comparing every point in the orbits he might as well tell us the closest average in the next and past 100 years. Then the answers might be different. Using the theory the sun is closer on average than any two planets are to each other.

Edited January 26, 2020 by Mobius

[JamesR]

Finished up my first image of 2020! This is an image of an open star cluster known as Melotte 15. This star cluster is at the center of the Heart Nebula, near the constellation Cassiopeia. This picture is focused on the center, the entire nebula really does look like a heart. The stars at the center are young and some of the big ones are 50 times as massive as our own sun. The light from the nebula region is mostly coming from ionized hydrogen with some sulfur and oxygen. The heart nebula is around 7500 light years from us. This image has 21 hours of exposure, taken with a 70mm triplet refractor, a monochrome camera and three filters (Ha, O3 & S2).

 

 

[Tim Sielbeck]

Sweet!

[Corinthian]

Beautiful shot, JamesR!

 

I am missing one piece of my astrophotography rig which is the ASIAir Pro. Alas, recent issues means I'll be able to get it later in the year. I will instead have to use my laptop which severely limits the places where I can shoot the night sky.

 

My current rig:

 

Lumix GX85

Olympus 50-150mm f4-5.6 telefoto

Leica Summilux 15mm prime

iOptron SkyGuider Pro tracker

ZSO120mini + ZSO 30mm guidescope

 

Would really love to have the SpaceCat telescope for astrophotography but the import duties will easily make it almost twice the price.

[lucklucky]

Very nice, What we would see with just our eyes? - i mean if they had more range -

Edited January 28, 2020 by lucklucky

[JamesR]

Beautiful shot, JamesR!

 

I am missing one piece of my astrophotography rig which is the ASIAir Pro. Alas, recent issues means I'll be able to get it later in the year. I will instead have to use my laptop which severely limits the places where I can shoot the night sky.

 

My current rig:

 

Lumix GX85

Olympus 50-150mm f4-5.6 telefoto

Leica Summilux 15mm prime

iOptron SkyGuider Pro tracker

ZSO120mini + ZSO 30mm guidescope

 

Would really love to have the SpaceCat telescope for astrophotography but the import duties will easily make it almost twice the price.

 

Thanks!

 

I'm very fortunate to be doing this from my backyard. We recently moved to a darker area on the outskirts of the population center. My commute is 30 mins longer but it's well worth it.

 

That sucks about the import duties but your rig sounds pretty good. You should still be able to do a lot with it.

[JamesR]

Very nice, What we would see with just our eyes? - i mean if they had more range -

Thanks!

 

If our eyes had increased sensitivity to see the color from great distances, I'm guessing it would be closer to an RGB view, and so it would be very red. Ionized hydrogen (Ha) is the dominate source of light and its red on the visual spectrum. Next would be Sulfur (S2) and its deeper in the red than hydrogen. Oxygen (O3) is a teal color. For this image, I used whats known as the Hubble palette. I mapped Ha to the green channel, used S2 for red and O3 for blue, that way the structures of each are visible.

 

That said, these nebulae stretch for light years and yet their density is very low... so if you were to get up close to it in a spaceship or something.. I don't know that you would see anything.. perhaps a thin fog. Certainly nothing like what you see in the pictures.

[Corinthian]

 

Beautiful shot, JamesR!

 

I am missing one piece of my astrophotography rig which is the ASIAir Pro. Alas, recent issues means I'll be able to get it later in the year. I will instead have to use my laptop which severely limits the places where I can shoot the night sky.

 

My current rig:

 

Lumix GX85

Olympus 50-150mm f4-5.6 telefoto

Leica Summilux 15mm prime

iOptron SkyGuider Pro tracker

ZSO120mini + ZSO 30mm guidescope

 

Would really love to have the SpaceCat telescope for astrophotography but the import duties will easily make it almost twice the price.

 

Thanks!

 

I'm very fortunate to be doing this from my backyard. We recently moved to a darker area on the outskirts of the population center. My commute is 30 mins longer but it's well worth it.

 

That sucks about the import duties but your rig sounds pretty good. You should still be able to do a lot with it.

 

True. I just need an external power source that I can bring with me to power my laptop because the software for autotracking needs a plugged laptop. The cheapest solution is to use the car and plug the laptop through the cigarette lighter port. But again, that limits the places I could shoot.

[lucklucky]

 

Very nice, What we would see with just our eyes? - i mean if they had more range -

Thanks!

 

If our eyes had increased sensitivity to see the color from great distances, I'm guessing it would be closer to an RGB view, and so it would be very red. Ionized hydrogen (Ha) is the dominate source of light and its red on the visual spectrum. Next would be Sulfur (S2) and its deeper in the red than hydrogen. Oxygen (O3) is a teal color. For this image, I used whats known as the Hubble palette. I mapped Ha to the green channel, used S2 for red and O3 for blue, that way the structures of each are visible.

 

That said, these nebulae stretch for light years and yet their density is very low... so if you were to get up close to it in a spaceship or something.. I don't know that you would see anything.. perhaps a thin fog. Certainly nothing like what you see in the pictures.

 

 

Yeah i guess it would very smallish fog, are we seeing some sort of atmosphere ?

 

[Ssnake]

I just need an external power source that I can bring with me to power my laptop because the software for autotracking needs a plugged laptop. The cheapest solution is to use the car and plug the laptop through the cigarette lighter port. But again, that limits the places I could shoot.

 

A cigarette port connected to a car battery, and a car batter charger?

Lugging car batteries around sucks, too. But it might give you that little extra mobility. Could serve as a tripod stabilizer, too.

[JamesR]

 

 

Very nice, What we would see with just our eyes? - i mean if they had more range -

Thanks!

 

If our eyes had increased sensitivity to see the color from great distances, I'm guessing it would be closer to an RGB view, and so it would be very red. Ionized hydrogen (Ha) is the dominate source of light and its red on the visual spectrum. Next would be Sulfur (S2) and its deeper in the red than hydrogen. Oxygen (O3) is a teal color. For this image, I used whats known as the Hubble palette. I mapped Ha to the green channel, used S2 for red and O3 for blue, that way the structures of each are visible.

 

That said, these nebulae stretch for light years and yet their density is very low... so if you were to get up close to it in a spaceship or something.. I don't know that you would see anything.. perhaps a thin fog. Certainly nothing like what you see in the pictures.

 

 

Yeah i guess it would very smallish fog, are we seeing some sort of atmosphere ?

 

 

 

Just concentrations of ionized gas and dust. The center column in my picture is a region where stars are created.

[lucklucky]

Thanks.

[Panzermann]

 

I just need an external power source that I can bring with me to power my laptop because the software for autotracking needs a plugged laptop. The cheapest solution is to use the car and plug the laptop through the cigarette lighter port. But again, that limits the places I could shoot.

 

A cigarette port connected to a car battery, and a car batter charger?

Lugging car batteries around sucks, too. But it might give you that little extra mobility. Could serve as a tripod stabilizer, too.

 

 

Get a small handcart to transport all the gear? A trailer for your mountain bike?

 

 

---

 

 

in other news:

 

 

we were told by our parents not to look directly into the sun. Better leave this to the professionals:

 

 

Astronomers have just released the highest-resolution image of the sun. Taken by the Daniel K. Inouye Solar Telescope in Maui, it gives us an unprecedented view of our nearest star and brings us closer to solving several long-standing mysteries.

The new image demonstrates the telescope’s potential power. It shows off a surface that’s divided up into discrete, Texas-size cells, like cracked sections in the desert soil. You can see plasma oozing off the surface, rising high into the solar atmosphere before sinking back into darker lanes.

“We have now seen the smallest details on the largest object in our solar system,” says Thomas Rimmele, the director of DKIST. The new image was taken December 10, when the telescope achieved first light. It is still technically under construction, with three more instruments set to come online.

(...)

 

more and photos at linky:

https://www.technologyreview.com/s/615113/these-are-the-highest-resolution-photos-of-the-sun-ever-taken/

Edited January 30, 2020 by Panzermann

[Corinthian]

Panzermann: Yes, was thinking of a cart carrying a car battery and modified to have a second shelf/platform to put the laptop on. A DC-AC power inverter in the 500 watt range I think will be sufficient. The autoguiding software won't work if the laptop is operating on its own battery, so the need to hook it up to a car battery. The problem though is that while mobile, it is difficult to haul in the places where I'd like to bring it (far from parking and up the hill on foot trails). Still, a solution.

 

I'm looking at the cost though, and it's just a bit less expensive and much more prone to failure (e.g., laptop can accidentally be dropped or get wet and it's done) than the ASIAir Pro, so I might just wait for the funding to arrive and plonk the serious cash on the ASIAir Pro instead.

 

2020 should be the year I get the ASIAir Pro.

 

2021 is the year I get the Spacecat telescope.

 

Edited February 2, 2020 by Corinthian

[JamesR]

Panzermann: Yes, was thinking of a cart carrying a car battery and modified to have a second shelf/platform to put the laptop on. A DC-AC power inverter in the 500 watt range I think will be sufficient. The autoguiding software won't work if the laptop is operating on its own battery, so the need to hook it up to a car battery. The problem though is that while mobile, it is difficult to haul in the places where I'd like to bring it (far from parking and up the hill on foot trails). Still, a solution.

 

I'm looking at the cost though, and it's just a bit less expensive and much more prone to failure (e.g., laptop can accidentally be dropped or get wet and it's done) than the ASIAir Pro, so I might just wait for the funding to arrive and plonk the serious cash on the ASIAir Pro instead.

 

2020 should be the year I get the ASIAir Pro.

 

2021 is the year I get the Spacecat telescope.

 

The spacecat looks likes a pretty slick setup. I've seen a number of really nice shots taken with them.