by Ann » Fri Oct 20, 2023 6:44 am
Well, nice! It's always interesting to see comets in the company of deep-sky objects. Some absolutely lovely images were taken when Comet C/2014 Q2 Lovejoy passed near the Pleiades (and the Hyades, and the California Nebula). A gorgeous picture was taken by Leonardo Orazi:
Compared with the sizzling colors of the deep-sky objects in Leonardo Orazi's image, the background galaxies in today's APOD look bland. And indeed, the most famous picture of galaxy M106 is so much more colorful than what we can see in today's APOD:
Wow, sizzling!!! But the colors here are either mapped (the infrared data) or very saturated. The appearance of M106 in today's APOD is not wrong, but the colors are very
unsaturated. However, other objects in the APOD are nicely colored, for example
blue B-type star HD 106420,
orange K-type star SAO 44089 and
yellowish late G-type star HD 106556 (which is whiter in color than I just suggested):
The star colors here look good. So we have very good reasons to believe that NGC 4217 (at left in the picture) is dominated by stars like yellow HD 106556 and orange SAO 44089.
And of course it's really funny that a green comet is called C/2023 H2 Lemmon! It doesn't look much like a lemon.
But frankly it doesn't look much like a lime either, but more like a green traffic light:
Neither a lemon nor a lime, but a green traffic light! That's what almost all comets are. And the light is always green when comets are moving along their own orbital "roads" in the solar system.
Unless, of course, their orbital roads cause the comets to hit an obstacle. Such as the Sun.
Click to play embedded YouTube video.
Ouch! There should have been a red light for that comet! Instead, there was blinding white light, incredible heat and incineration.
Ann
[img3="Galaxies and a Comet.
Image Credit & Copyright: Dan Bartlett"]https://apod.nasa.gov/apod/image/2310/C2023H2LemmonGalaxies1024.jpg[/img3]
Well, nice! It's always interesting to see comets in the company of deep-sky objects. Some absolutely lovely images were taken when Comet C/2014 Q2 Lovejoy passed near the Pleiades (and the Hyades, and the California Nebula). A gorgeous picture was taken by Leonardo Orazi:
[img3="Cyan-green comet with a blue tail, C/2014 Q2 Lovejoy passing near yellow-orange Aldebaran in the Hyades, blue Pleiades and red California Nebula. Credit and copyright: Leonardo Orazi."]https://www.universetoday.com/wp-content/uploads/2015/01/15665979044_41f01d051f_z.jpg[/img3]
Compared with the sizzling colors of the deep-sky objects in Leonardo Orazi's image, the background galaxies in today's APOD look bland. And indeed, the most famous picture of galaxy M106 is so much more colorful than what we can see in today's APOD:
[img3="M106 in visible and infrared light. Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany"]https://upload.wikimedia.org/wikipedia/commons/thumb/2/2d/Messier_106_visible_and_infrared_composite.jpg/1280px-Messier_106_visible_and_infrared_composite.jpg[/img3]
Wow, sizzling!!! But the colors here are either mapped (the infrared data) or very saturated. The appearance of M106 in today's APOD is not wrong, but the colors are very [b][i][color=#FF0000]un[/color][/i][/b]saturated. However, other objects in the APOD are nicely colored, for example [b][color=#0080FF]blue[/color][/b] B-type star HD 106420, [b][color=#FF8000]orange[/color][/b] K-type star SAO 44089 and [b][color=#FFBF00]yellowish[/color][/b] late G-type star HD 106556 (which is whiter in color than I just suggested):
[attachment=0]NGC 4217 plus yellow HD 106556 orange SAO 44089 and blue HD 106420 Dan Bartlett.png[/attachment]
The star colors here look good. So we have very good reasons to believe that NGC 4217 (at left in the picture) is dominated by stars like yellow HD 106556 and orange SAO 44089.
And of course it's really funny that a green comet is called C/2023 H2 Lemmon! It doesn't look much like a lemon. 🍋 But frankly it doesn't look much like a lime either, but more like a green traffic light:
[float=right][img3="A green traffic light."]https://www.rightsdirect.com/wp-content/uploads/sites/6/2018/08/Die-Loesung-ist-so-einfach-300x200.jpg[/img3][/float][float=left][img3="A lime."]https://amblerpurespa.com/wp-content/uploads/2016/08/Lime-web.jpeg[/img3][/float]
[clear][/clear]
Neither a lemon nor a lime, but a green traffic light! That's what almost all comets are. And the light is always green when comets are moving along their own orbital "roads" in the solar system.
Unless, of course, their orbital roads cause the comets to hit an obstacle. Such as the Sun.
[youtube]https://www.youtube.com/watch?v=QNhlflwVHj0[/youtube]
Ouch! There should have been a red light for that comet! Instead, there was blinding white light, incredible heat and incineration.
Ann