Difúzní mlhovina
Difúzní mlhovina je astronomický objekt tvořen oblaky mezihvězdné hmoty nacházející se v blízkosti hvězd a hvězdokup. Jasné mlhoviny jsou obvykle tvořeny ohromnými koncentracemi plynů a prachu ze kterých byly, či právě jsou tvořeny hvězdy. Od temné mlhoviny se liší tím, že v ní dochází k rozptylu světla.
Rozdělení difúzních mlhovin
Difúzní mlhoviny lze rozdělit do následujících kategorií:
Emisní mlhovina
Emisní mlhovina je mezihvězdný oblak vodíku, který září díky intenzivní radiaci šířící se z velmi horké hmotné hvězdy skrývající se v jeho nitru. Mračna těchto mlhovin jsou často zbarvena dočervena.
- Ukázky emisních mlhovin
Jasná mlhovina N 164
Mlhovina DR6
Reflexní mlhovina
Reflexní mlhoviny jsou prachová a plynová mračna, která žádné světlo sama nevyzařují, ale světlo díky vysoké koncentraci prachu odráží od blízkých hvězd. Odražené světlo má barvu dle spektra hvězdy, jejíž světlo odráží, nejčastěji však modrou či modrobílou.
- Ukázky reflexních mlhovin
IRAS 12116-6001
NGC 1579
IC 349
Mlhovina v blízkosti hvězdy HD 87643
WR 102ka
Pozůstatek supernovy
Zvláštní kategorií mlhovin je pozůstatek po supernově. Pozůstatek supernovy vzniká na sklonku života velmi hmotné hvězdy, která exploduje a tím vyvrhne své vnější vrstvy do mezihvězdného prostoru.
Nejznámějším takovýmto pozůstatkem je Krabí mlhovina, jež vznikla po výbuchu supernovy, která byla pozorována roku 1054.
- Ukázky pozůstatků supernov
(c) Vatican Observatory, CC BY-SA 3.0
SNR 0543-689
Puppis A Chandra + ROSAT
N 63A
Poměrně často lze pozorovat, že některé difuzní mlhoviny vykazují vlastnosti jak emisních, tak také reflexních mlhovin.
Média použitá na této stránce
IRAS 12116-6001.jpg
Image of the reflection nebula IRAS 12116-6001. This cloud of interstellar dust cannot be seen directly in visible light, but WISE’s detectors observed the nebula at infrared wavelengths. The bright blue star on the right side of the image is the variable star Epsilon Crucis. The colours used in this image represent specific wavelengths of infrared light. The blue colour of Epsilon Crucis represents light emitted at 3.4 and 4.6 microns. The green-coloured star seen beside Epsilon Crucis is emitting light at 12 microns. This star is IRAS 12194-6007, a carbon star that is near the end of its life-cycle. Since the infrared wavelengths emitted by this star are longer than those from Epsilon Crucis, it is cooler. The green and red colours seen in the reflection nebula represent 12- and 22-micron light coming from the nebula’s dust grains warmed by nearby stars.
Image of the reflection nebula IRAS 12116-6001. This cloud of interstellar dust cannot be seen directly in visible light, but WISE’s detectors observed the nebula at infrared wavelengths. The bright blue star on the right side of the image is the variable star Epsilon Crucis. The colours used in this image represent specific wavelengths of infrared light. The blue colour of Epsilon Crucis represents light emitted at 3.4 and 4.6 microns. The green-coloured star seen beside Epsilon Crucis is emitting light at 12 microns. This star is IRAS 12194-6007, a carbon star that is near the end of its life-cycle. Since the infrared wavelengths emitted by this star are longer than those from Epsilon Crucis, it is cooler. The green and red colours seen in the reflection nebula represent 12- and 22-micron light coming from the nebula’s dust grains warmed by nearby stars.
N1579atlas.jpg
NGC 1579
NGC 1579
ESO- Reflection Nebula around HD 87643-phot-28a-09-fullres.jpg
Autor: ESO, Licence: CC BY 3.0
This image, centred on the B[e] star HD 87643, beautifully shows the extended nebula of gas and dust that reflects the light from the star. The central star's wind appears to have shaped the nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years. The image, taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla, is based on data obtained through different filters: B, V and R.
Autor: ESO, Licence: CC BY 3.0
This image, centred on the B[e] star HD 87643, beautifully shows the extended nebula of gas and dust that reflects the light from the star. The central star's wind appears to have shaped the nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years. The image, taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla, is based on data obtained through different filters: B, V and R.
Peony nebula.jpg
The Peony Nebula star taken by NASA's Spitzer Space Telescope in its naturally dusty region
The Peony Nebula star taken by NASA's Spitzer Space Telescope in its naturally dusty region
DR6nebula.jpg
The DR 6 cluster of stars
The DR 6 cluster of stars
Puppis A Chandra + ROSAT.jpg
The Chandra three-color image (inset) of a region of the supernova remnant Puppis A (wide-angle view from ROSAT in blue) reveals a cloud being torn apart by a shock wave produced in a supernova explosion. This is the first X-ray identification of such a process in an advanced phase. In the inset, the blue vertical bar and the blue fuzzy ball or cap to the right show how the cloud has been spread out into an oval-shaped structure that is almost empty in the center. The Chandra data also provides information on the temperature in and around the cloud, with blue representing higher temperature gas. The oval structure strongly resembles those seen on much smaller size scales in experimental simulations of the interaction of supernova shock waves with dense interstellar clouds (see sequence of laboratory images). In these experiments, a strong shock wave sweeps over a vaporized copper ball that has a diameter roughly equal to a human hair. The cloud is compressed, and then expands in about 40 nanoseconds to form an oval bar and cap structure much like that seen in Puppis A.
The Chandra three-color image (inset) of a region of the supernova remnant Puppis A (wide-angle view from ROSAT in blue) reveals a cloud being torn apart by a shock wave produced in a supernova explosion. This is the first X-ray identification of such a process in an advanced phase. In the inset, the blue vertical bar and the blue fuzzy ball or cap to the right show how the cloud has been spread out into an oval-shaped structure that is almost empty in the center. The Chandra data also provides information on the temperature in and around the cloud, with blue representing higher temperature gas. The oval structure strongly resembles those seen on much smaller size scales in experimental simulations of the interaction of supernova shock waves with dense interstellar clouds (see sequence of laboratory images). In these experiments, a strong shock wave sweeps over a vaporized copper ball that has a diameter roughly equal to a human hair. The cloud is compressed, and then expands in about 40 nanoseconds to form an oval bar and cap structure much like that seen in Puppis A.
FlamingStarHunterWilson.jpg
Autor: Hewholooks, Licence: CC BY-SA 3.0
IC 405 - The "Flaming Star Nebula"
Autor: Hewholooks, Licence: CC BY-SA 3.0
IC 405 - The "Flaming Star Nebula"
SBIG ST-4000XCM 15x15min Imager Temp -20C APM/TMB 130/780 Field Flattenerref. http://hwilson.zenfolio.com/emission/h3590e589#h3590e589
Reflection nebula IC 349 near Merope.jpg
Reflection nebula IC 349 near Merope in the Pleiades. From http://hubblesite.org/newscenter/newsdesk/archive/releases/2000/36/.
Reflection nebula IC 349 near Merope in the Pleiades. From http://hubblesite.org/newscenter/newsdesk/archive/releases/2000/36/.
ESO- N 164 Nebula in the LMC-phot-34e-04-fullres.jpg
Autor: ESO, Licence: CC BY 3.0
N 164, a bright nebula, the glow of which is caused by hot stars inside it. The heating of the gas by these stars increases the pressure and causes such nebulae to expand, pushing outwards against their surroundings. A careful look at this nebula reveals locations where the expansion is encountering resistance by denser clouds of gas, producing bright, thin rims. The sky field measures 3.6 x 3.5 arcmin. North is up and East is left.
Autor: ESO, Licence: CC BY 3.0
N 164, a bright nebula, the glow of which is caused by hot stars inside it. The heating of the gas by these stars increases the pressure and causes such nebulae to expand, pushing outwards against their surroundings. A careful look at this nebula reveals locations where the expansion is encountering resistance by denser clouds of gas, producing bright, thin rims. The sky field measures 3.6 x 3.5 arcmin. North is up and East is left.
STScl-2005-15.png
A Hubble Space Telescope image of the supernova remnant N 63A in the Large Magellanic Cloud.
A Hubble Space Telescope image of the supernova remnant N 63A in the Large Magellanic Cloud.
ESO-SNR 0543-689 in the LMC-phot-34c-04-fullres.jpg
Autor: ESO, Licence: CC BY 3.0
This is a bright, compact nebula that is located on the North-Western rim of the ringshaped nebula DEM L 299. It is known as SNR 0543-689 and it is the remnant of a more recent supernova explosion. The sky field measures 3.6 x 3.5 arcmin. North is up and East is left.
Autor: ESO, Licence: CC BY 3.0
This is a bright, compact nebula that is located on the North-Western rim of the ringshaped nebula DEM L 299. It is known as SNR 0543-689 and it is the remnant of a more recent supernova explosion. The sky field measures 3.6 x 3.5 arcmin. North is up and East is left.
CrabNebula VATT.jpg
(c) Vatican Observatory, CC BY-SA 3.0
The Crab Nebula (Messier 1) is a well-known supernova remnant (the remains from massive star whose life ended in a massive explosion). This false-color image of the Crab Nebula was taken at the Vatican Observatory on Mount Graham using Sloan u’, g’, and r’ filters. The yellow filaments on the outside of the remnant are primarily ionized hydrogen gas and show up in both the u’ and r’ filters. The gas in the interior of the nebula is heated by the neutron star left by the explosion and its glowing light is visible in all the filters. While the neutron star itself is too faint to be see in the visible, the glowing disk of gas and debris that surround it also shows up quite clearly in the g’ filter (blue-white colors). One of the jets thrown off by the accreting neutron star is also partially visible in the g’ filter to the lower-left of the accretion disk.
(c) Vatican Observatory, CC BY-SA 3.0
The Crab Nebula (Messier 1) is a well-known supernova remnant (the remains from massive star whose life ended in a massive explosion). This false-color image of the Crab Nebula was taken at the Vatican Observatory on Mount Graham using Sloan u’, g’, and r’ filters. The yellow filaments on the outside of the remnant are primarily ionized hydrogen gas and show up in both the u’ and r’ filters. The gas in the interior of the nebula is heated by the neutron star left by the explosion and its glowing light is visible in all the filters. While the neutron star itself is too faint to be see in the visible, the glowing disk of gas and debris that surround it also shows up quite clearly in the g’ filter (blue-white colors). One of the jets thrown off by the accreting neutron star is also partially visible in the g’ filter to the lower-left of the accretion disk.
CaveHunterWilson.jpg
Autor: Hewholooks, Licence: CC BY-SA 3.0
Sh2-155 - Cave Nebula in Cepheus by amateur equipment. Blue reflection nebula vdB 155 is present at the lower right. LDN1215 an LDN1214 are protruding in from the right over top of vdB 155. Other interesting structures, such as the curly spring or "pig tail" dark nebula on the left seems to be nameless.
Autor: Hewholooks, Licence: CC BY-SA 3.0
Sh2-155 - Cave Nebula in Cepheus by amateur equipment. Blue reflection nebula vdB 155 is present at the lower right. LDN1215 an LDN1214 are protruding in from the right over top of vdB 155. Other interesting structures, such as the curly spring or "pig tail" dark nebula on the left seems to be nameless.