Tuesday, April 20, 2010

How Much For Guests To Attend Destination Wedding

Doublet

variable star observers, especially those monitoring cataclysmic variables, these days are going to be a bit busier. Outbursts of this kind of stars are giving to a certain frequency, nonperiodic, but most of the time these systems are in a state of minimum brightness.

U Geminorum

Sometimes, however, may overlap in time the eruptions, as a purely fortuitous no other impact that we can enjoy the sight of two peaks simultaneously, as happened between 18 and 20 April 2010 with two well-known dwarf novae: U Geminorum and SS Aurigae (the latter has occupied a post month past) .

SS Aurigae

us not lose these two explosions.

Monday, April 12, 2010

Mojave Indian Tribe Folklore

A star explodes in the bowels of the galaxy NGC2357

The supernova number 63 of 2010 was discovered on 27 March, Cox and Puckett observers in the galaxy NGC 2357. As shown in the picture, the 2357 is a spiral galaxy presumably ready to sing, so before us as a thin object, well defined borders reminiscent of the drawing of a cigar.

is assumed that the supernova exploded in a peripheral area of \u200b\u200bthe galaxy, otherwise, in a location closer to the center can be significantly obscured by dust and interstellar gas of NGC 2357 to make very hard to detect. Evidence of this is the supernovae that have occurred in M82 galaxy also ready to chant, usually difficult to observe because of the material interposed between us and the phenomenon.


This is the strong wind and which encouraged the search for supernovas in galaxies that we face "in front" with the entire structure of arms to the eye and in the thickness of dust and gas is minimal and will not exercise an obstacle to detect this cataclysm in all its glory. But perhaps not as photogenic as this bj, although clearly detected, but this fascination with seeing that faint star embedded in the galaxy. In the Bishop supernovae page more and much better images.

The 2010 is of type IIp. Is supposed to be a very massive star that had come to obtain fusion energy of all elements, successively, from hydrogen to iron (through Helium, Carbon, Neon, Oxygen and Silicon) begins a catastrophic melting of the latter in the nucleus, giving rise to what we see as a star that for a days or weeks can get to shine as bright as its host galaxy, or harder yet.

Friday, April 2, 2010

Pinnacle Pctv 150e/55e Program

greet Venus and Mercury

This Friday night the sky opened and let us wanted to see a little. My place of observation is facing west, which this month takes place April favorable simultaneous appearance Venus and Mercury. Although do not become a real conjunction, these days can be seen near sunset, to a minimum of 3 on 4 April.

Venus (the brightest, left) and Mercury (right) on the evening of April 2, 2010. Exhibition 2.5s F7.1 ISO200, 55mm F

is a great opportunity to delight with these two stars and take beautiful photographs of both planets on the horizon. A few seconds at ISO 200 with a digital SLR or a compact even on a tripod, give excellent Results like that can give an idea the photo I've taken a few minutes ago.

Thursday, April 1, 2010

Does Breast Cancer Metastasis To The Throat

dusk telescopes Fraunhoffer SS Aurigae

This entry is off the subject of variable stars to enter the world of astronomy back in the nineteenth and Joseph Fraunhoffer telescopes.

In February I had the opportunity to visit Munich, a city that has pretty good museums, and other attractions (besides the famous brewery). Not only the enjoyment of the collections of art and archeology museums invited to visit Munich, also, frankly, the need to remain covered with very cold weather prevailing in the area.



All of you blog readers, you are people, I guess interested in science and technology. Therefore I emphatically recommend visit the German Museum (Deutsches Museum ) of Munich. It is a compendium of technology and science in all its branches (in which Germany has been developing a role of protagonist in many cases). Created in the early twentieth century, remains in its original building, with appropriate upgrades, if While still a traditional exhibition in their collections, which are different from the modern science museum today, but subtract this interest to its contents.


has a good section devoted to astronomy, with special attention to observing instruments, plus a planetarium and observatory own. Of all that is exposed particularly caught my attention the historic instruments, including two telescopes were built by the great optical physicist Joseph von Fraunhofer (1787-1826) in the early 1820.
Refractor of 24 inches in diameter

The first of these, a doublet refractor Achromatic 24 cm aperture. This is already enough diameter for a refractor (refractors are rare in the openings between medium and large, since larger diameter, it is very difficult to make good lenses without defects, while the development of a mirror has fewer complications). It already had an equatorial mount, quite novel for its time, with the advantage of monitoring more convenient than counteracts the Earth's rotation for the observations.

And it has pedigree, this telescope was operating at the observatory in Berlin and was with that Galle discovered the planet Neptune by the calculations of Adams and Leverrier. Must be the second time I am facing a telescope with which new stars were discovered, the first being the 30-cm reflector opening of John Lacroix to be discovered dozens of asteroids in the observatory of La CaƱada ( Avila).
Fraunhoffer heliometer of

And then I admire heliometer approximately 8 cm in diameter, also Fraunfoffer. What is a heliometer? is a dedicated telescope to measure angular distances in the sky. For this objective lens is divided into two equal halves, and one of them can be turned respect to each other by a micrometer mechanism.

If the two halves are exactly aligned, the telescope will be observed for a normal image, but if we move one, we see a double image. with a shift in function of the angle in which they are rotated the lens sections.

That is the basis for measuring angular distances, like a micrometer traditional but more convenient and accurate, precisely for this purpose was invented by John Dollond optician in 1755. If we in the field view a double star, just have to move semiobjective until both stars of the pair together, so that the micrometer system, properly calibrated, can measure the angular distance of separation. Previously would have to rotate the shaft part the two halves to a perpendicular angle to the angle of position, which we would be measuring the second number that characterizes a par.

Fraunhoffer Portrait (Wikimedia commons)

This gadget has also served on the same ground, to measure with high precision the Sun's diameter, and hence its name. Until the advent of photography meridian circles and has been instrumental angular measurement more precise, to the extent that served a similar Bessel in 1838 for the first time to calculate the distance to land a star, 61 Cygni, using the parallax. You have to realize the precision to be reached this optical system to be able to measure such small angular distance of the order of tenths of a second of arc.

parallax diagram Barnard's Star, one of the closest to the Sun, as well as 61 Cygni. Both have a high annual proper motion, and therefore rightly astronomers had to be inferred that close and parallax could be measured with available techniques. David Richards diagram their own astrometric observations.



Portrait of Friedrich Wilhelm Bessel (1784-1846). Wikimedia Commons