APOD: NGC 1499: The California Nebula (2011 Mar 02)

[APOD Robot]

NGC 1499: The California Nebula

Explanation: What's California doing in space? Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun also lies within the Milky Way's Orion Arm, only about 1,500 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. On many images, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. In the above image, however, hydrogen is colored green, while sulfur is mapped to red and oxygen mapped to blue. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei, just outside the right image edge. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark sky toward the constellation of Perseus, not far from the Pleiades.

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[Beyond]

Hey!! Depending on your 'state of being', you can get free beer at the California Nebula!! Hip-Hip Hooray!

[neufer]

The Island of California, from a map circa 1650. Restored.

---

<<In the minds of European explorers, an island populated by Amazons off the coast of the Indies was a long-established expectation. The earliest known application of the name "California" to this island of the Amazons was in the romance novel Las Sergas de Esplandián (The Adventures of Esplandián) by Spanish author Garci Rodríguez de Montalvo, whose earliest surviving edition (but not first edition) is from 1510. The book described the Island of California as being east of the Asian mainland, "very close to the side of the Terrestrial Paradise; and it is peopled by black women, without any man among them, for they live in the manner of Amazons." The Island was ruled by Queen Calafia. In his work, the author drew on a long-standing European belief in such an island.

• Know that on the right hand from the Indies exists an island called California very close to a side of the Earthly Paradise; and it was populated by black women, without any man existing there, because they lived in the way of the Amazons. They had beautiful and robust bodies, and were brave and very strong. Their island was the strongest of the World, with its cliffs and rocky shores. Their weapons were golden and so were the harnesses of the wild beasts that they were accustomed to domesticate and ride, because there was no other metal in the island than gold.
  –Las Sergas de Esplandián, (novela de caballería) by García Ordóñez de Montalvo. Published in Seville in 1510.

Since then, that unknown Amazon's Island came to be known as California.

Some scholars speculate the Song of Roland, an 11th century Old French epic poem, may have served as the inspiration for the name California. It refers to the defeat suffered August 15, 778, in the retreat of Charlemagne's army at the hands of the Muslim army in Battle of Roncevaux Pass in the Pyrenees. On line 2924 of the poem, which is in verse number CCIX (209), the word Califerne is one of the lands mentioned, with no indication of its geographic location. It is, however, named after a reference to Affrike, or Africa.

• My nephew's dead, who won for me such realms!
  Against me then the Saxon will rebel,
  Hungar, Bulgar, and many hostile men,
  Romain, Puillain, all those are in Palerne,
  And in Affrike, and those in Califerne;
  –Song of Roland, Verse CCIX (i.e. 209; lines 2920–2924), 11th c.

"Since the Roland poem concerns the "evil" Saracens, it's possible that the poet derived Califerne from caliph. Montalvo might also have been influenced by such similar names as Californo and Calafornina in Sicily or Calahorra in Spain."

This notion of a place of women without men echoes a passage from the diary of Christopher Columbus's first voyage:

• The Indians told him that along that route he would find the island of Matinino, which they said was populated by women without men, to which the admiral replied he wanted very much to bring five or six of them to the king and queen… but they said that it was certain that [the women] existed and that at a certain time of the year men came to [the women] from the aforementioned island of Carib, which they said was ten or twelve leagues away, and if they gave birth to a son they sent it to the island of the men, and if a girl, they kept her with them.

The lure of an earthly paradise, as well as the search for the fabled Strait of Anián, helped motivate Hernán Cortés, following his conquest of Mexico, to send several expeditions in the late 1530s and early 1540s to the west coast of New Spain. The first expedition reached the Gulf of California and the Baja California peninsula, and proved that California was in fact a peninsula. Nevertheless, the idea that California was an island persisted for well over a century and was included on many maps. The Spanish gave the name "Las Californias" to the lower Baja California peninsula and to the upper northern mainlands later known as Alta California and U.S. California.>>

[tekic545]

The explanation of this image of NGC 1499 says that "silicon" is mapped to red. Ionized silicon? That's interesting. Who am I to question the professional astronomers who write these things? But somehow "sulfur" might make more sense.

Bob

[Chris Peterson]

The explanation of this image of NGC 1499 says that "silicon" is mapped to red. Ionized silicon? That's interesting. Who am I to question the professional astronomers who write these things? But somehow "sulfur" might make more sense.

Indeed, as can be seen from the link to the original image, red is mapped to SII, which is, of course, ionized sulfur.

(Silicon does show some strong emission lines in the visible spectrum, and can be isolated in various stars and nebulas.)

[neufer]

The explanation of this image of NGC 1499 says that "silicon" is mapped to red. Ionized silicon? That's interesting. Who am I to question the professional astronomers who write these things? But somehow "sulfur" might make more sense.

Indeed, as can be seen from the link to the original image, red is mapped to SII, which is, of course, ionized sulfur.

Then how do you explain the strong red color of Silicon Valley?

[tekic545]

I wouldnt attempt to explain Silicon Valley, but I do think the good folks at APOD, not being infallible, owe a small correction, or as news people call it in a vivid metaphor that conveys the pain involved in publicly acknowledging a mistake, a "skinback."

Bob

[owlice]

The text has been fixed.

[tekic545]

Good. Now to Chris Peterson's note that silicon does in fact show strong emission lines in some nebulae. Are these emissions strong enough that amateur equipment could capture them? If so, are silicon emission filters commercially available in the usual sizes?

Tnx,

Bob

[neufer]

Now to Chris Peterson's note that silicon does in fact show strong emission lines in some nebulae. Are these emissions strong enough that amateur equipment could capture them? If so, are silicon emission filters commercially available in the usual sizes?

How are you fixed for observing 34.8-micron radiation? (Or is that a Si II y question?)

Thus, most of the observed forbidden Si II 34.8-micron emission in Orion does not arise in the H II region.

[Chris Peterson]

Good. Now to Chris Peterson's note that silicon does in fact show strong emission lines in some nebulae. Are these emissions strong enough that amateur equipment could capture them? If so, are silicon emission filters commercially available in the usual sizes?

Yes to both. Triply ionized silicon (SiIV) is commonly observed from ground-based instruments. The strongest lines are around 315nm, which is technically near UV, but can be detected (with low efficiency) through the atmosphere by unmodified silicon detectors. There are several weaker lines at 410nm and longer which are perhaps easier.

[bystander]

Triply ionized silicon (SiIV)

Wouldn't (Si IV) be quadruply ionized silicon? Isn't that what the IV means?

[Chris Peterson]

Triply ionized silicon (SiIV)

Wouldn't (Si IV) be quadruply ionized silicon? Isn't that what the IV means?

SiI - neutral silicon
SiII - singly ionized silicon
SiIII - doubly ionized silicon
SiIV - triply ionized silicon

[bystander]

Ok, thanks. I've been reading these wrong.

Note to self: Start with 1 not 0. It's not C programming.

[Beyond]

Ok, thanks. I've been reading these wrong.

Note to self: Start with 1 not 0. It's not C programming.

That's ok, bystander. It's all Oscar's fault. He erased the line and no one knows quite where to stand when starting something anymore.

[NoelC]

Ok, thanks. I've been reading these wrong.

Likewise, and we're not alone. Randomly chosen, one of the first matches of a Google search for "SII ionized": http://www.flickriver.com/photos/eifels ... 639672682/

-Noel

[neufer]

I'm Halogen the septuply ionized I am
Halogen the septuply ionized I am, I am
I got separated from the electron next door
She's been removed six times before
And every one was from an Halogen (Halogen)
She wouldn't leave a Willy or a Sam (no Sam)
I'm her septuply ionized Halogen (Halogen)
Halogen the septuply ionized I am

[owlice]

Oh, neufer!!!

That song -- with the original text -- brings back memories from so long ago!
Oh!

[bystander]

Second verse, same as the first

[Beyond]

How many Hen-erys we got here? Eight

[Crash]

Are we loosing the proverbial forest?
Big question is, how close does one have to be to CalNeb to see it flip over. (See enlarged images)
Crash

[garry]

Electrons stripped away by energetic starlight? What an unscientific phrase! It would be more scientific to call it plasma.Plasma will strip away electrons, starlight will not. Energetic starlight sounds as though it was written by a 12 year old who is clueless as to the forces at work in the Universe.

[bystander]

I think you are the one who is clueless. Light (electromagnetic radiation) can and does strip electrons.