Starship Asterisk*

neufer wrote:

geckzilla wrote:I think what I'm really getting caught up on is that I never understood how a camera attaches to and works with a telescope.

The simplest way is to remove the lens of the camera and position the film/plate/CCD to be at the focal plane.

geckzilla wrote:
I think what I'm really getting caught up on is that I never understood how a camera attaches to and works with a telescope.

geckzilla wrote:I think I need a picture book for dummies on this.

rstevenson wrote:

geckzilla wrote:
What do you mean by flash photo? The "flash" part is confusing me. Surely you don't mean firing a flash.

Shirley rarely means what he says.

http://en.wikipedia.org/wiki/The_Travels_of_the_Three_English_Brothers wrote:
<<The Travels of the Three English Brothers is an early Jacobean era stage play, an adventure drama written in 1607 by John Day, William Rowley, and George Wilkins. The drama was based on the true-life experiences of the three Shirley brothers, Sir Anthony Shirley, Sir Thomas Shirley, and Robert Shirley. Since George Wilkins is thought by some to have worked with Shakespeare on Pericles, Prince of Tyre around 1607, the question of his participation in this collaboration has drawn the attention of some Shakespeare scholars. The play was acted by Queen Anne's Men. Its 29 July Register entry states that the play was performed at the Curtain Theatre, though this information is likely inaccurate; The Queen's company is thought to have moved on to the Red Bull Theatre in 1604 or 1605. Francis Beaumont's The Knight of the Burning Pestle, also of 1607, refers to The Travels as a Red Bull play.

Beyond the sheer entertainment value of the Shirleys' story, the dramatists were eager to draw cultural contrasts between Christian England and Muslim Persia, the key locale of much of the Shirley saga. Their play stresses the violence and brutality of Persian society (especially the practice of beheading) as a blatant discriminator between Persia and England. The English display their valor and resourcefulness when assaulted by violence and treachery; when an unarmed Sir Thomas Shirley is attacked by four Turks, he defends himself with rocks. The splendid English move the Persian "Sophy" (the play's version of the Shah) to verbal raptures — and inspire him to grant Christians tolerance in his dominions.

In addition to other real-life figures in the cast of characters (including the Pope), the comic Will Kempe appears in one scene. Himself noted for his travels, Kempe is shown in Venice, where he has a bawdy exchange with a Signor Harlakin (that is, harlequin) and his wife. Kempe reportedly met Sir Anthony Shirley in Rome; but whether this Venetian scene with Kempe is based on anything more substantial that the playwrights' imaginations is uncertain.

The final scene in The Travels of the Three English Brothers contains a noteworthy feature: the three Shirley brothers and their father, widely separate geographically, see and speak with each other through a magical device called a "perspective glass." This device is part of the traditional lore of magic, and occurs in other contexts: Robert Greene includes it in his Friar Bacon and Friar Bungay. Though the perspective glass operates thaumaturgically rather than technologically, it nonetheless provides a striking anticipation of modern communications.>>

geckzilla wrote:What do you mean by flash photo? The "flash" part is confusing me. Surely you don't mean firing a flash.

neufer wrote:

geckzilla wrote:
What I've been wondering is whether it's a projection on to a black surface which one can then take a photo of or if the light goes straight into a camera something else. Sadly, I don't have a telescope so there are a few things that mystify me.

Project on to a black surface and then take a flash photo of it.

geckzilla wrote:
What do you mean by flash photo? The "flash" part is confusing me.

Surely you don't mean firing a flash.

geckzilla wrote:
What I've been wondering is whether it's a projection on to a black surface which one can then take a photo of or if the light goes straight into a camera something else. Sadly, I don't have a telescope so there are a few things that mystify me.

geckzilla wrote:It might be too much to ask but I am interested in a more detailed explanation for how this was made.

Ann wrote:

neufer wrote:

Ann wrote:
shouldn't we see a few obvious lines from other elements than hydrogen?

http://spaceweather.com/gallery/indiv_u ... d_id=85616

Thanks, Art, I appreciate your reply. However, I don't really understand it. The link you provided seems to say that we really only do see hydrogen lines in the spectrum of Nova Delphini. I was wondering about this very fact. Why aren't there other lines in the spectrum of Nova Delphini?

• The APOD clearly shows other lines which my link identifies as FeII lines.

http://astrobob.areavoices.com/2013/08/23/nova-in-delphinus-transforms-into-a-celestial-chameleon/ wrote:

[b][color=#FF0000]Nova Delphini 2013 on Aug. 21. Credit: John Chumack[/color][/b]

---

Nova in Delphinus transforms into a celestial chameleon
by Astrobob, Aug. 23, 2013

<<Through the telescope the nova has been a colorful sight. Early on it twinkled pale yellow but now has deepened in hue to yellow-orange. It’s still in the fireball phase with the white dwarf star hidden by fiery hydrogen gas and an expanding cloud of debris.

As novae evolve they’ll often turn from white or yellow to red. Emission of what’s called hydrogen alpha light gives novae their warm, red color. Hydrogen, the most common element in stars, gets excited through intense radiation or collisions with atoms (heat). Once energized, hydrogen’s electrons “move upstairs”, ie. jump from a lower energy level to a higher one. Just as quickly, they can drop back down “downstairs”. When they do, each releases a smidge of light in the deep red end of the rainbow spectrum called hydrogen alpha or H-alpha. Nova-red comes from electrons dropping from the “third floor” to the “second floor” inside the hydrogen atom.

Novae take on a pink or red color for several reasons according to Arne Henden, director of the American Association of Variable Star Observers (AAVSO). “Energy from the explosion gets absorbed by the surrounding material in a nova and re-emitted as H-alpha,” said Henden. Not only that but as the explosion expands over time, the same amount of energy is spread over a larger area. “The temperature drops,” said Henden, “causing the fireball to cool and turn redder on its own.” As the eruption expands and cools, materials blasted into the surrounding space condense into a shell of soot that absorbs that reddens the nova much the same way dusty air reddens the sun.

So why does it appear yellow-orange right now? “That’s the underlying continuum (bluish light from the explosion) mixing with the H-alpha from the expanding fireball. Red and blue together make orange.”

Finally, I’m often asked how far away the nova is. According to two studies based on the rate of decline in the nova’s brightness, the star is either 11,400 or 17,900 light years from Earth. Very far! That means it must be incredibly brilliant. A lot’s going on right now with Nova Delphini – an expanding fireball, formation of a debris cloud, cooling and reddening. And to think you can sample all this with little more than a pair of binoculars from your front yard. Amazing.>>

neufer wrote:

Ann wrote:
shouldn't we see a few obvious lines from other elements than hydrogen?

http://spaceweather.com/gallery/indiv_u ... d_id=85616

Ann wrote:
shouldn't we see a few obvious lines from other elements than hydrogen?

neufer wrote:Sounds good to me.

Anthony Barreiro wrote:
Why are the absorption lines blueshifted relative to the emission lines? I'm trying to picture the sequence of events, but my mental house of cards collapses before reaching a stable equilibrium. Hydrogen from a companion star falls onto a white dwarf, eventually triggering a thermonuclear explosion which we see as a nova. The explosion blows hydrogen out into space. The hydrogen in the cloud around the white dwarf is absorbing and emitting photons at the Balmer wavelengths, thus we see the Hydrogen alpha, etc. emission lines. The hydrogen in the gas that is directly between us and the still glowing nova absorbs photons at the Balmer wavelengths and re-emits them in random directions, causing the absorption lines. The gas that is directly between us and the white dwarf is traveling toward us faster than any of the other gas, so the absorption lines appear slightly blue-shifted.

After trying three or four times, I think I've figured it out. Is this right?

Ann wrote:I love this picture, and I have already written a rather long comment on what can be learnt from these spectra. I'm going to paste my previous comment here:

...

8) We can see that there appear to be bright emission lines right next to the dark absorption lines. Nova Delphini therefore appears to have a P Cygni spectrum, where dark absorption lines are bordered (on the red side) by bright emission lines. This feature means that we are looking at ejecta coming our way, or, in other words, we are looking at fragments from an explosion.

So the picture is indeed highly informative!

Ann

drollere wrote:
Hipparcos is the preferred spelling for the satellite and catalog.

• And though thou hadst small Latine, and lesse Greeke,
  From thence to honour thee, I would not seeke

Giza Guy wrote:

3.162277660168379 wrote:Absolutely wonderful and so educational.

sqrt 2 X sqrt 5 = 3.162277660168379