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Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Sun Sep 03, 2023 8:27 pm
by johnnydeep
orin stepanek wrote: βSun Sep 03, 2023 7:20 pm
emc wrote: βSun Sep 03, 2023 9:28 am
orin stepanek wrote: βSat Sep 02, 2023 8:26 pm
268_lorand_fenyes_iris_ngc7023_1024.jpg
I grow Iris flowers and I love them! I even have a pretty blue one
like the nebula!
I finally got your joke but I had to visit your Flowers Around the House thread to get it. You funny Orin!
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
Me slow!
Hi; I really do grow Iris; And I love the Iris Nebula! To me The Iris is an orchid; as it is a very delicate flower! I'll try to get a photo of it when it is in bloom. I have been having trouble downloading photos from my Canon 100 lately, but by the time the orchids are in bloom I should get it figured out!
At the risk of showing zero sense of humor, what's the joke? This is the Iris Nebula and Orin apparently grow irises.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Sun Sep 03, 2023 11:46 pm
by Chris Peterson
johnnydeep wrote: βSun Sep 03, 2023 6:49 pm
In response to Ann's explanation of electrons changing quantum orbits, why is it that a high energy photon can raise an electron into a higher orbit, but it can emit a lower energy photon to transition back down to a lower orbit? Does that only happen if the electron steps down in orbital stages, which requires a less energetic photon to be emitted at each step down, but the sum total of energy of the photons emitted would still add up to the energy of the initial photon that raised the orbit multiple levels?
The absorption of an energetic photon by a hydrogen atom almost never results in elevating an electron into a higher orbital. What usually happens is that the atom is ionized- the electron is completely ejected. At some point the ionized hydrogen atom picks up a free electron, and the wavelength that is emitted depends on the specific transition or transitions that occur (cascades to the lowest energy level are common, and in that cascade the n=3 to n=2 transition happens half the time, so ionized H regions are strong emitters of H-alpha light.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Sun Sep 03, 2023 11:57 pm
by Chris Peterson
Ann wrote: βSun Sep 03, 2023 5:58 pm
Nitin Khuthia wrote: βSun Sep 03, 2023 5:10 pm
this is my first post and as i cant find any place to start or join discussion i am using this. please guide me to right place if this not. my apologies beforehand.
with reference to the explanation
" the star's invisible ultraviolet radiation to visible red light. I"
i believe the nearest spectrum to ultraviolet is violet and not red so is it actually ultraviolet is converted to red or infrared converted to red?
if there is some mistake it may be corrected.
thanks
It works something like this...
Something like that. But it's still quite different. Your example describes what happens in a cloud of ionized gas- a nicely simple system. Here we're talking about photoluminescence- a much more complex process that occurs when an electron is absorbed in a solid material (so you have multiple atoms involved) and an assortment of quantum effects become involved. For one thing there can be a very long delay between the absorption and subsequent emission (think about things that glow in the dark for a long time after being exposed to light). For another, there is no single emission wavelength. The red light that is emitted by interstellar dust when stimulated by UV light is called
Extended Red Emission, ERE. It has a broad wavelength range, starting as low as 540 nm and extending to the near IR... with the actual peak dependent upon the intensity of the stimulating light, the size of the dust particle, the angle of incidence, and maybe other things. And this broad emission appears to have no structure (like embedded peaks).
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 12:51 am
by alter-ego
johnnydeep wrote: βSun Sep 03, 2023 12:55 pm
Ann wrote: βSun Sep 03, 2023 4:50 am
alter-ego wrote: βSun Sep 03, 2023 12:16 am
Based on GAIA pm data for this star, I calculate the time difference to be ~23 years.
β’ There is a large proper motion in declination. Proper motion in RA and Dec = 5.6 mas/yr and 101 mas/yr respectively, or a total pm β 102 mas/yr
β’ The angular change β 2.3 arcseconds
β 2.3 arcseconds Γ· 0.1 arcseconds/yr = 23 years
Thanks, alter-ego, I'm so impressed by your skills in math! Thanks for using it here at Starship Asterisk* to help us understand things that have to do with APODs!
You have apparently identified the "flying star". I used Simbad to try to identify it, to get a designation for it, but I failed.
All I got was the star next to it (to the west of it), 2MASS J21010772+6808005.
Did you get a designation for the fast moving star? How else could you get a proper motion for it?
In order to know the star's proper motion we need to know its true distance, right? Oh, you just calculated its displacement across the sky between the two images, right?
No, wait, you used Gaia! How did you do that? I have never used Gaia to try to find a star!
Ann
And even more importantly, how fast does this mean the star is actually moving in km/s?
The parallax of this star = 3.29 Β± 0.1 β β 304 Β± 10pc
The total velocity β 147 Β± 5 km/s
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 2:08 am
by alter-ego
Ann wrote: βSun Sep 03, 2023 4:50 am
alter-ego wrote: βSun Sep 03, 2023 12:16 am
AVAO wrote: βSat Sep 02, 2023 8:28 pm
Good question. DSS2 was produced between 1996 and 2006. That means there should be 17-27 years between the two pictures...
Based on GAIA pm data for this star, I calculate the time difference to be ~23 years.
β’ There is a large proper motion in declination. Proper motion in RA and Dec = 5.6 mas/yr and 101 mas/yr respectively, or a total pm β 102 mas/yr
β’ The angular change β 2.3 arcseconds
β 2.3 arcseconds Γ· 0.1 arcseconds/yr = 23 years
Thanks, alter-ego, I'm so impressed by your skills in math! Thanks for using it here at Starship Asterisk* to help us understand things that have to do with APODs!
You have apparently identified the "flying star". I used Simbad to try to identify it, to get a designation for it, but I failed.
All I got was the star next to it (to the west of it), 2MASS J21010772+6808005.
Did you get a designation for the fast moving star? How else could you get a proper motion for it?
In order to know the star's proper motion we need to know its true distance, right? Oh, you just calculated its displacement across the sky between the two images, right?
No, wait, you used Gaia! How did you do that? I have never used Gaia to try to find a star!
Ann
Thank you, I'm glad I could help.
If you can independently find the coordinates for a star in question, you can enter them in a search box at the Gaia website:
Gaia Home page, then click search tab. Depending on how well you know the coordinates you can also enter a search area size to include the star. However, it's probably better to go to the Aladin website via the
CDS website. Search for the Iris nebula. Here you'll get a familiar scalable image of the nebula. You can select the Gaia DR3 layer (may take a while to load). Click on the star in question (Gaia layer shows hollow squares) and the data shows up on the screen:
Turns out this star only has numbering ID:
Gaia DR3 2270239585757069312.
Alternatively, I like using the free downloadable Aladin desktop which is easier to get more results with less work:
Β
Enabling the DR3 layer, and clicking on the star, you'll see a scrollable row of Gaia data at the bottom. Clicking on the
Source_ID box takes you a Vizier page which includes other star cross-IDs:
Β
Hope this helps you.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 12:49 pm
by johnnydeep
alter-ego wrote: βMon Sep 04, 2023 12:51 am
johnnydeep wrote: βSun Sep 03, 2023 12:55 pm
Ann wrote: βSun Sep 03, 2023 4:50 am
Thanks, alter-ego, I'm so impressed by your skills in math! Thanks for using it here at Starship Asterisk* to help us understand things that have to do with APODs!
You have apparently identified the "flying star". I used Simbad to try to identify it, to get a designation for it, but I failed.
All I got was the star next to it (to the west of it), 2MASS J21010772+6808005.
Did you get a designation for the fast moving star? How else could you get a proper motion for it?
In order to know the star's proper motion we need to know its true distance, right? Oh, you just calculated its displacement across the sky between the two images, right?
No, wait, you used Gaia! How did you do that? I have never used Gaia to try to find a star!
Ann
And even more importantly, how fast does this mean the star is actually moving in km/s?
The parallax of this star = 3.29 Β± 0.1 β β 304 Β± 10pc
The total velocity β 147 Β± 5 km/s
Thanks! That's only about 330,000 mph. Surprisingly - to me - that seems not very fast at all.
[ EDIT: but, wait - this is just the speed perpendicular (or parallel?) to our line of sight, right? And if so, it could be moving much faster along its direction of motion. ]
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 12:57 pm
by johnnydeep
Chris Peterson wrote: βSun Sep 03, 2023 11:46 pm
johnnydeep wrote: βSun Sep 03, 2023 6:49 pm
In response to Ann's explanation of electrons changing quantum orbits, why is it that a high energy photon can raise an electron into a higher orbit, but it can emit a lower energy photon to transition back down to a lower orbit? Does that only happen if the electron steps down in orbital stages, which requires a less energetic photon to be emitted at each step down, but the sum total of energy of the photons emitted would still add up to the energy of the initial photon that raised the orbit multiple levels?
The absorption of an energetic photon by a hydrogen atom almost never results in elevating an electron into a higher orbital. What usually happens is that the atom is ionized- the electron is completely ejected. At some point the ionized hydrogen atom picks up a free electron, and the wavelength that is emitted depends on the specific transition or transitions that occur (cascades to the lowest energy level are common, and in that cascade the n=3 to n=2 transition happens half the time, so ionized H regions are strong emitters of H-alpha light.
Ah, ok, thanks. Hopefully I'll remember this when it comes time to ask about it again.
![:) :ssmile:](./images/smilies/smile.gif)
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 1:40 pm
by Chris Peterson
johnnydeep wrote: βMon Sep 04, 2023 12:49 pm
alter-ego wrote: βMon Sep 04, 2023 12:51 am
johnnydeep wrote: βSun Sep 03, 2023 12:55 pm
And even more importantly, how fast does this mean the star is actually moving in km/s?
The parallax of this star = 3.29 Β± 0.1 β β 304 Β± 10pc
The total velocity β 147 Β± 5 km/s
Thanks! That's only about 330,000 mph. Surprisingly - to me - that seems not very fast at all.
[ EDIT: but, wait - this is just the speed perpendicular (or parallel?) to our line of sight, right? And if so, it could be moving much faster along its direction of motion. ]
Proper motion gives us the tangential speed. Doppler shift gives us the radial speed. The two vectors can be combined to give us the (3D) velocity.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 1:48 pm
by johnnydeep
Chris Peterson wrote: βMon Sep 04, 2023 1:40 pm
johnnydeep wrote: βMon Sep 04, 2023 12:49 pm
alter-ego wrote: βMon Sep 04, 2023 12:51 am
The parallax of this star = 3.29 Β± 0.1 β β 304 Β± 10pc
The total velocity β 147 Β± 5 km/s
Thanks! That's only about 330,000 mph. Surprisingly - to me - that seems not very fast at all.
[ EDIT: but, wait - this is just the speed perpendicular (or parallel?) to our line of sight, right? And if so, it could be moving much faster along its direction of motion. ]
Proper motion gives us the tangential speed. Doppler shift gives us the radial speed. The two vectors can be combined to give us the (3D) velocity.
Ah, right - of course! So the calculation with
parallax parsecs (distance, determined by Doppler shift of the spectrum) gives the radial speed, and the visually observed mas change over 23 years will provide the tangential (along a line perpendicular to our line of sight) speed.
[ Note: edited to correct my typo of parallax for parsecs. ]
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 1:51 pm
by johnnydeep
orin stepanek wrote: βSun Sep 03, 2023 7:20 pm
emc wrote: βSun Sep 03, 2023 9:28 am
orin stepanek wrote: βSat Sep 02, 2023 8:26 pm
268_lorand_fenyes_iris_ngc7023_1024.jpg
I grow Iris flowers and I love them! I even have a pretty blue one
like the nebula!
I finally got your joke but I had to visit your Flowers Around the House thread to get it. You funny Orin!
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
Me slow!
Hi; I really do grow Iris; And I love the Iris Nebula! To me The Iris is an orchid; as it is a very delicate flower! I'll try to get a photo of it when it is in bloom. I have been having trouble downloading photos from my Canon 100 lately, but by the time the orchids are in bloom I should get it figured out!
Ok, nice. Please post one of your best Iris pics to this thread when you do.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 1:56 pm
by Chris Peterson
johnnydeep wrote: βMon Sep 04, 2023 1:48 pm
Chris Peterson wrote: βMon Sep 04, 2023 1:40 pm
johnnydeep wrote: βMon Sep 04, 2023 12:49 pm
Thanks! That's only about 330,000 mph. Surprisingly - to me - that seems not very fast at all.
[ EDIT: but, wait - this is just the speed perpendicular (or parallel?) to our line of sight, right? And if so, it could be moving much faster along its direction of motion. ]
Proper motion gives us the tangential speed. Doppler shift gives us the radial speed. The two vectors can be combined to give us the (3D) velocity.
Ah, right - of course! So the calculation with parallax gives the radial speed, and the mas change over 23 years will provide the tangential (to our line of sight) speed.
We don't need the parallax measurement for radial speed, just the Doppler shift. Two or more measurements of position where that value changes gives us the proper motion, and the proper motion, combined with parallax (i.e. distance) gives us tangential speed.
Gaia is fundamentally a position measuring instrument, although it does have instrumentation capable of measuring spectra.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 2:00 pm
by johnnydeep
Chris Peterson wrote: βMon Sep 04, 2023 1:56 pm
johnnydeep wrote: βMon Sep 04, 2023 1:48 pm
Chris Peterson wrote: βMon Sep 04, 2023 1:40 pm
Proper motion gives us the tangential speed. Doppler shift gives us the radial speed. The two vectors can be combined to give us the (3D) velocity.
Ah, right - of course! So the calculation with parallax gives the radial speed, and the mas change over 23 years will provide the tangential (to our line of sight) speed.
We don't need the parallax measurement for radial speed, just the Doppler shift. Two or more measurements of position where that value changes gives us the proper motion, and the proper motion, combined with parallax (i.e. distance) gives us tangential speed.
Gaia is fundamentally a position measuring instrument, although it does have instrumentation capable of measuring spectra.
Thanks. Damn, I mangled my words, and was thinking "parsec" (distance measurement) when I wrote parallax. D'oh!
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 4:54 pm
by Ann
johnnydeep wrote: βMon Sep 04, 2023 2:00 pm
Chris Peterson wrote: βMon Sep 04, 2023 1:56 pm
johnnydeep wrote: βMon Sep 04, 2023 1:48 pm
Ah, right - of course! So the calculation with parallax gives the radial speed, and the mas change over 23 years will provide the tangential (to our line of sight) speed.
We don't need the parallax measurement for radial speed, just the Doppler shift. Two or more measurements of position where that value changes gives us the proper motion, and the proper motion, combined with parallax (i.e. distance) gives us tangential speed.
Gaia is fundamentally a position measuring instrument, although it does have instrumentation capable of measuring spectra.
Thanks. Damn, I mangled my words, and was thinking "parsec" (distance measurement) when I wrote parallax. D'oh!
Like Han Solo saying his Millennium Falcon made the Kessel run in less than twelve parsecs?
(And I'm not laughing at you, but at the mistakes and logical flip flops that I'm guilty of myself. Oh, and maybe I'm laughing at whoever wrote that part of the script for Star Wars...)
Ann
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 5:01 pm
by Ann
alter-ego wrote: βMon Sep 04, 2023 2:08 am
Ann wrote: βSun Sep 03, 2023 4:50 am
alter-ego wrote: βSun Sep 03, 2023 12:16 am
Based on GAIA pm data for this star, I calculate the time difference to be ~23 years.
β’ There is a large proper motion in declination. Proper motion in RA and Dec = 5.6 mas/yr and 101 mas/yr respectively, or a total pm β 102 mas/yr
β’ The angular change β 2.3 arcseconds
β 2.3 arcseconds Γ· 0.1 arcseconds/yr = 23 years
Thanks, alter-ego, I'm so impressed by your skills in math! Thanks for using it here at Starship Asterisk* to help us understand things that have to do with APODs!
You have apparently identified the "flying star". I used Simbad to try to identify it, to get a designation for it, but I failed.
All I got was the star next to it (to the west of it), 2MASS J21010772+6808005.
Did you get a designation for the fast moving star? How else could you get a proper motion for it?
In order to know the star's proper motion we need to know its true distance, right? Oh, you just calculated its displacement across the sky between the two images, right?
No, wait, you used Gaia! How did you do that? I have never used Gaia to try to find a star!
Ann
Thank you, I'm glad I could help.
If you can independently find the coordinates for a star in question, you can enter them in a search box at the Gaia website:
Gaia Home page, then click search tab. Depending on how well you know the coordinates you can also enter a search area size to include the star. However, it's probably better to go to the Aladin website via the
CDS website. Search for the Iris nebula. Here you'll get a familiar scalable image of the nebula. You can select the Gaia DR3 layer (may take a while to load). Click on the star in question (Gaia layer shows hollow squares) and the data shows up on the screen:
Aladin Lite.jpg
Turns out this star only has numbering ID:
Gaia DR3 2270239585757069312.
Alternatively, I like using the free downloadable Aladin desktop which is easier to get more results with less work:
Aladin Desktop.jpg
Β
Enabling the DR3 layer, and clicking on the star, you'll see a scrollable row of Gaia data at the bottom. Clicking on the
Source_ID box takes you a Vizier page which includes other star cross-IDs:
Vizier Cross-IDs.jpg
Β
Hope this helps you.
Thank you so much for your help! Maybe I'll be able to use Gaia myself in the future, but I
am slow on the uptake, really. I remember how much bystander had to sweat in order to make me understand how to post large images as attachments without uploading them to my computer. Remember that, bystander?
But thanks again, alter-ego! I very much appreciate your help! Maybe I'll even be able to use Gaia myself thanks to you, but I make no promises.
Ann
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 6:01 pm
by johnnydeep
Ann wrote: βMon Sep 04, 2023 4:54 pm
johnnydeep wrote: βMon Sep 04, 2023 2:00 pm
Chris Peterson wrote: βMon Sep 04, 2023 1:56 pm
We don't need the parallax measurement for radial speed, just the Doppler shift. Two or more measurements of position where that value changes gives us the proper motion, and the proper motion, combined with parallax (i.e. distance) gives us tangential speed.
Gaia is fundamentally a position measuring instrument, although it does have instrumentation capable of measuring spectra.
Thanks. Damn, I mangled my words, and was thinking "parsec" (distance measurement) when I wrote parallax. D'oh!
Like Han Solo saying his Millennium Falcon made the Kessel run in less than twelve parsecs?
(And I'm not laughing at you, but at the mistakes and logical flip flops that I'm guilty of myself. Oh, and maybe I'm laughing at whoever wrote that part of the script for Star Wars...)
Ann
Star Wars apologists will argue that using parsecs in that way is easily explained by taking the use of parsec in this phrase, not as a blockheaded misconstrued unit of time, but as the proper unit of distance it really is as follows:
https://www.wired.com/2013/02/kessel-run-12-parsecs/ wrote:
According to
Star Wars: The Essential Atlas, the Kessel Run was an 18-parsec (59 light-year) route used by smugglers to get around Imperial blockades. So why would Solo describe how quickly he traveled it using a word that described distance?
It turns out that the expanded universe of the Star Wars franchise β the additional books and content created within the Star Wars universe but outside of the films β contains an answer to that question. The Essential Atlas maps a Kessel Run whose path travels around βThe Maw,β a cluster of black holes. To cut down on the distance traveled, pilots could dangerously skirt the edges of the black holes, while trying to avoid spaghettification. If Solo was a skilled enough β or crazy enough β pilot to deviate from the typical route and fly close enough to the black holes to cut nearly 20 light-years off his space odometer, then his ship was fast indeed β the power required to stay out of the gape of an event horizon is something worth bragging about.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 6:28 pm
by Ann
johnnydeep wrote: βMon Sep 04, 2023 6:01 pm
Ann wrote: βMon Sep 04, 2023 4:54 pm
johnnydeep wrote: βMon Sep 04, 2023 2:00 pm
Thanks. Damn, I mangled my words, and was thinking "parsec" (distance measurement) when I wrote parallax. D'oh!
Like Han Solo saying his Millennium Falcon made the Kessel run in less than twelve parsecs?
(And I'm not laughing at you, but at the mistakes and logical flip flops that I'm guilty of myself. Oh, and maybe I'm laughing at whoever wrote that part of the script for Star Wars...)
Ann
Star Wars apologists will argue that using parsecs in that way is easily explained by taking the use of parsec in this phrase, not as a blockheaded misconstrued unit of time, but as the proper unit of distance it really is as follows:
https://www.wired.com/2013/02/kessel-run-12-parsecs/ wrote:
According to
Star Wars: The Essential Atlas, the Kessel Run was an 18-parsec (59 light-year) route used by smugglers to get around Imperial blockades. So why would Solo describe how quickly he traveled it using a word that described distance?
It turns out that the expanded universe of the Star Wars franchise β the additional books and content created within the Star Wars universe but outside of the films β contains an answer to that question. The Essential Atlas maps a Kessel Run whose path travels around βThe Maw,β a cluster of black holes. To cut down on the distance traveled, pilots could dangerously skirt the edges of the black holes, while trying to avoid spaghettification. If Solo was a skilled enough β or crazy enough β pilot to deviate from the typical route and fly close enough to the black holes to cut nearly 20 light-years off his space odometer, then his ship was fast indeed β the power required to stay out of the gape of an event horizon is something worth bragging about.
Yeah, yeah, yeah.
I once argued with a creationist and told him that astronomy and science in general does not, in fact, corroborate his claim that humans and dinosaurs were contemporaries - you should have heard his long-winded and huffy defense for his position that Noah did, in fact, invite a pair of dinosaurs to his ark...
![π¦](//cdn.jsdelivr.net/gh/twitter/twemoji@latest/assets/svg/1f995.svg)
![π¦](//cdn.jsdelivr.net/gh/twitter/twemoji@latest/assets/svg/1f995.svg)
I guess that believing that Star Wars tells you the truth about space is not quite so serious as believing in dinosaurs on Noah's ark (and believing in Noah's ark in the first place) - or is it?
Ann
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 6:47 pm
by johnnydeep
Ann wrote: βMon Sep 04, 2023 6:28 pm
johnnydeep wrote: βMon Sep 04, 2023 6:01 pm
Ann wrote: βMon Sep 04, 2023 4:54 pm
Like Han Solo saying his Millennium Falcon made the Kessel run in less than twelve parsecs?
(And I'm not laughing at you, but at the mistakes and logical flip flops that I'm guilty of myself. Oh, and maybe I'm laughing at whoever wrote that part of the script for Star Wars...)
Ann
Star Wars apologists will argue that using parsecs in that way is easily explained by taking the use of parsec in this phrase, not as a blockheaded misconstrued unit of time, but as the proper unit of distance it really is as follows:
https://www.wired.com/2013/02/kessel-run-12-parsecs/ wrote:
According to
Star Wars: The Essential Atlas, the Kessel Run was an 18-parsec (59 light-year) route used by smugglers to get around Imperial blockades. So why would Solo describe how quickly he traveled it using a word that described distance?
It turns out that the expanded universe of the Star Wars franchise β the additional books and content created within the Star Wars universe but outside of the films β contains an answer to that question. The Essential Atlas maps a Kessel Run whose path travels around βThe Maw,β a cluster of black holes. To cut down on the distance traveled, pilots could dangerously skirt the edges of the black holes, while trying to avoid spaghettification. If Solo was a skilled enough β or crazy enough β pilot to deviate from the typical route and fly close enough to the black holes to cut nearly 20 light-years off his space odometer, then his ship was fast indeed β the power required to stay out of the gape of an event horizon is something worth bragging about.
Yeah, yeah, yeah.
I once argued with a creationist and told him that astronomy and science in general does not, in fact, corroborate his claim that humans and dinosaurs were contemporaries - you should have heard his long-winded and huffy defense for his position that Noah did, in fact, invite a pair of dinosaurs to his ark...
![π¦](//cdn.jsdelivr.net/gh/twitter/twemoji@latest/assets/svg/1f995.svg)
![π¦](//cdn.jsdelivr.net/gh/twitter/twemoji@latest/assets/svg/1f995.svg)
I guess that believing that Star Wars tells you the truth about space is not quite so serious as believing in dinosaurs on Noah's ark (and believing in Noah's ark in the first place) - or is it?
Ann
The parsec explanation was no doubt contrived after the fact of the script blunder, but it is believable under that path length interpretation, unlike all creationist arguments.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Mon Sep 04, 2023 7:11 pm
by Chris Peterson
orin stepanek wrote: βSun Sep 03, 2023 7:20 pm
emc wrote: βSun Sep 03, 2023 9:28 am
orin stepanek wrote: βSat Sep 02, 2023 8:26 pm
268_lorand_fenyes_iris_ngc7023_1024.jpg
I grow Iris flowers and I love them! I even have a pretty blue one
like the nebula! :D
I finally got your joke but I had to visit your Flowers Around the House thread to get it. You funny Orin! :mrgreen: Me slow! :mrgreen:
Hi; I really do grow Iris; And I love the Iris Nebula! To me The Iris is an orchid; as it is a very delicate flower! I'll try to get a photo of it when it is in bloom. I have been having trouble downloading photos from my Canon 100 lately, but by the time the orchids are in bloom I should get it figured out! π
I don't need to grow them... they grow wild here, in abundance in late spring! Certainly one of my favorite wildflowers (but they aren't orchids). So from here in Colorado, here's what I see looking up, and then looking down.
_
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Tue Sep 05, 2023 3:10 pm
by orin stepanek
Chris Peterson wrote: βMon Sep 04, 2023 7:11 pm
orin stepanek wrote: βSun Sep 03, 2023 7:20 pm
emc wrote: βSun Sep 03, 2023 9:28 am
I finally got your joke but I had to visit your Flowers Around the House thread to get it. You funny Orin!
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
Me slow!
Hi; I really do grow Iris; And I love the Iris Nebula! To me The Iris is an orchid; as it is a very delicate flower! I'll try to get a photo of it when it is in bloom. I have been having trouble downloading photos from my Canon 100 lately, but by the time the orchids are in bloom I should get it figured out!
I don't need to grow them... they grow wild here, in abundance in late spring! Certainly one of my favorite wildflowers (but they aren't orchids). So from here in Colorado, here's what I see looking up, and then looking down.
_
two-irises.jpg
Ah Chris; To me they are like orchids and I know they aren't but I looked it up and they are related! Mine are more like this!
![OIP.jpg](./download/file.php?id=48266&sid=459e8bb3f78f4e1f96e50dc785cb89f4)
- OIP.jpg (9.68 KiB) Viewed 5683 times
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Tue Sep 05, 2023 6:17 pm
by johnnydeep
orin stepanek wrote: βTue Sep 05, 2023 3:10 pm
Chris Peterson wrote: βMon Sep 04, 2023 7:11 pm
orin stepanek wrote: βSun Sep 03, 2023 7:20 pm
Hi; I really do grow Iris; And I love the Iris Nebula! To me The Iris is an orchid; as it is a very delicate flower! I'll try to get a photo of it when it is in bloom. I have been having trouble downloading photos from my Canon 100 lately, but by the time the orchids are in bloom I should get it figured out!
I don't need to grow them... they grow wild here, in abundance in late spring! Certainly one of my favorite wildflowers (but they aren't orchids). So from here in Colorado, here's what I see looking up, and then looking down.
_
two-irises.jpg
Ah Chris; To me they are like orchids and I know they aren't but I looked it up and they are related! Mine are more like this!OIP.jpg
I'd say they're really not that related. They're in different phylogenetic families (Orchidaceae versus Iridaceae), but are at least in the same order (Monocot).
From
https://flowerpursuits.com/are-orchids- ... s-related/
Short Answer
Orchids and irises belong to different plant families.
Orchids are part of the Orchidaceae family, and irises are part of the Iridaceae family.
However, both families are part of the larger monocot order of plants, which includes grasses, lilies, and palms.
They also both share some similar characteristics such as having showy blooms and sword-shaped foliage
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Tue Sep 05, 2023 6:40 pm
by Ann
Chris Peterson wrote: βMon Sep 04, 2023 7:11 pm
orin stepanek wrote: βSun Sep 03, 2023 7:20 pm
emc wrote: βSun Sep 03, 2023 9:28 am
I finally got your joke but I had to visit your Flowers Around the House thread to get it. You funny Orin!
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
Me slow!
Hi; I really do grow Iris; And I love the Iris Nebula! To me The Iris is an orchid; as it is a very delicate flower! I'll try to get a photo of it when it is in bloom. I have been having trouble downloading photos from my Canon 100 lately, but by the time the orchids are in bloom I should get it figured out!
I don't need to grow them... they grow wild here, in abundance in late spring! Certainly one of my favorite wildflowers (but they aren't orchids). So from here in Colorado, here's what I see looking up, and then looking down.
_
Absolutely lovely, Chris!
Ann
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Wed Sep 06, 2023 12:04 am
by orin stepanek
johnnydeep wrote: βTue Sep 05, 2023 6:17 pm
orin stepanek wrote: βTue Sep 05, 2023 3:10 pm
Chris Peterson wrote: βMon Sep 04, 2023 7:11 pm
I don't need to grow them... they grow wild here, in abundance in late spring! Certainly one of my favorite wildflowers (but they aren't orchids). So from here in Colorado, here's what I see looking up, and then looking down.
_
two-irises.jpg
Ah Chris; To me they are like orchids and I know they aren't but I looked it up and they are related! Mine are more like this!OIP.jpg
I'd say they're really not that related. They're in different phylogenetic families (Orchidaceae versus Iridaceae), but are at least in the same order (Monocot).
From
https://flowerpursuits.com/are-orchids- ... s-related/
Short Answer
Orchids and irises belong to different plant families.
Orchids are part of the Orchidaceae family, and irises are part of the Iridaceae family.
However, both families are part of the larger monocot order of plants, which includes grasses, lilies, and palms.
They also both share some similar characteristics such as having showy blooms and sword-shaped foliage
I just repeated what was in the info file of the computer! what difference does it make anyway! I just gave my feelings about it anyhow!
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Wed Sep 06, 2023 3:52 am
by Ann
orin stepanek wrote: βWed Sep 06, 2023 12:04 am
johnnydeep wrote: βTue Sep 05, 2023 6:17 pm
orin stepanek wrote: βTue Sep 05, 2023 3:10 pm
Ah Chris; To me they are like orchids and I know they aren't but I looked it up and they are related! Mine are more like this!OIP.jpg
I'd say they're really not that related. They're in different phylogenetic families (Orchidaceae versus Iridaceae), but are at least in the same order (Monocot).
From
https://flowerpursuits.com/are-orchids- ... s-related/
Short Answer
Orchids and irises belong to different plant families.
Orchids are part of the Orchidaceae family, and irises are part of the Iridaceae family.
However, both families are part of the larger monocot order of plants, which includes grasses, lilies, and palms.
They also both share some similar characteristics such as having showy blooms and sword-shaped foliage
I just repeated what was in the info file of the computer! what difference does it make anyway! I just gave my feelings about it anyhow!
No sweat, Orin. I remember that in his
Cosmos TV show (from back in the eighties?), Carl Sagan said that humans and oak trees are closely related!
I bet irises and orchids are a bit more closely related than that!
Ann
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Wed Sep 06, 2023 3:56 am
by Chris Peterson
Ann wrote: βWed Sep 06, 2023 3:52 am
orin stepanek wrote: βWed Sep 06, 2023 12:04 am
I just repeated what was in the info file of the computer! what difference does it make anyway! I just gave my feelings about it anyhow!
No sweat, Orin. I remember that in his
Cosmos TV show (from back in the eighties?), Carl Sagan said that humans and oak trees are closely related!
I bet irises and orchids are a bit more closely related than that! :D
Ann
Go back far enough, and we're all related. Every living thing on Earth descends from LUCA, the last universal common ancestor. About 4 billion years ago.
Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Posted: Wed Sep 06, 2023 12:56 pm
by johnnydeep
Chris Peterson wrote: βWed Sep 06, 2023 3:56 am
Ann wrote: βWed Sep 06, 2023 3:52 am
orin stepanek wrote: βWed Sep 06, 2023 12:04 am
I just repeated what was in the info file of the computer! what difference does it make anyway! I just gave my feelings about it anyhow!
No sweat, Orin. I remember that in his
Cosmos TV show (from back in the eighties?), Carl Sagan said that humans and oak trees are closely related!
I bet irises and orchids are a bit more closely related than that!
Ann
Go back far enough, and we're all related. Every living thing on Earth descends from LUCA, the last universal common ancestor. About 4 billion years ago.
Yeah, and in another sense, literally
everything is related - rocks, stars, humans, microbes, water, plasma, etc. - since we're all made out of the same fundamental particles adhering to the same fundamental forces. ...Well, perhaps black holes are in a class by themselves.