On Thursday, Nadine shared a DVD with us by Louie Giglio – Indescribable. Cool, cool stuff about our truly INDESCRIBABLE GOD! Anyhow, it got me to poking around the NASA website today where I found their Photo-of-the-Day archives. Just wanted to share a couple I found particularly lovely. The text from here on down in this post is from NASA.gov.

Andromeda in UltravioletIn a break from its usual task of searching for distant cosmic explosions, NASA’s Swift satellite acquired the highest-resolution view of a neighboring spiral galaxy ever attained in the ultraviolet. The galaxy, known as M31 in the constellation Andromeda, is the largest and closest spiral galaxy to our own. This mosaic of M31 merges 330 individual images taken by Swift’s Ultraviolet/Optical Telescope. The image shows a region 200,000 light-years wide and 100,000 light-years high (100 arcminutes by 50 arcminutes).

Image Credit: NASA/Swift/Stefan Immler (GSFC) and Erin Grand (UMCP)

Omega Centauri

NASA’s Hubble Space Telescope snapped this panoramic view of a colorful assortment of 100,000 stars residing in the crowded core of a giant star cluster. This is one of the first images taken by the new Wide Field Camera 3 that was installed aboard Hubble in May 2009 during Servicing Mission 4, which can snap sharp images over a broad range of wavelengths.

Image Credit: NASA

M31-Andromeda Galaxy on 11/25/09

I recently bought a 135mm f/2.8 lens off of eBay. It’s an old Soligar (it’s about my age) and has a manual focus, Because my DSI uses a T-mount as well as this lens, I just bought a couple spacers and now I’m able to use my DSI to take widefield shots like this one. With my telescope, I can’t get the entire Andromeda Galaxy into the frame with my DSLR, but with this lens, it fits on my little DSI just fine. I hope to do a more imaging like this soon.

Here we see Andromeda galaxy as viewed from above. The spiral arms and structure becomes visible clearly in this processed image with a distortion nearly equivalent to a change of the observer location from our galaxy to a point in the void intergalactic space just above M31.

The original image from which this perspective has been obtained was a 4 minutes exposure with a 300mm telephoto lens and a DSLR Canon EOS 450d (Rebel XTi) camera.

Os dejo una impresionante imagen de la galaxia M31, en la constelación de Andrómeda, la más grande y cercana galaxia en espiral a nosotros. Es una combinación de 330 imágenes tomadas por el Swift’s Ultraviolet/Optical Telescope.

Andrómeda en ultravioleta

Ofrecida por la NASA.

Considering how long it’s been since my last post, I felt that this entry needed to be truly stellar. The trouble was, in doing research, much of the most interesting material I came across regarding stars seemed to be made up.¹ That wouldn’t do. Then, with expectations flagging, I found it: galactic collisions. Galactic collisions make for beautiful pictures and take place on a massive, galaxy-shattering scale that can only be described by words like “epic,” “monumental,” and “holy shit!”² They also take an interesting variety of forms. Some galaxies dance peacefully together, ever so slightly avoiding actual collision. Others merge like lovers, taking all the metaphor out of the phrase “when two become one.” For other galaxies, their collisions are more akin to hit-and-run accidents, or even cannibalism.

The Whirlpool galaxy and its companion NGC 5195 are a wonderful example of cosmic dance. The little NGC 5195 has been passing alongside the Whirlpool galaxy for millions of years. The gravitational interaction of these two partners has likely had great effect on both, sharpening the larger’s two distinct spiral arms and contributing to the smaller’s own amorphous form.

More intimately, the Antennae galaxies have forgone mere dancing, to merge together in blissful, if fiery, harmony. Once, they were two independent spiral galaxies, but hundreds of millions of years of courtship has brought them together so that they are barely distinguishable from one another. A few hundred million years more may find them merged completely, but give them time; in cosmic terms, they’re a young couple yet.

Another young couple is the Mice galaxies. While they are expected to merge like the Antennae, the Mice are still in the less intense phase of their merge, still dancing around one another, interacting, but still relatively distinct, flirting with the idea of union.

In stark contrast to these lover galaxies is the Cartwheel galaxy, who looks like a hit-and-run victim. The Cartwheel’s distinctive ripple-in-a-pond look is the result of a nasty head-on collision with a smaller galaxy, which then continued on its merry way, leaving the Cartwheel galaxy to sort itself out alone.

On the flip side of the smaller galaxy’s David-versus-Goliath drubbing of the Cartwheel, is galactic cannibalism, which occurs when large galaxies devour their smaller companions whole or in part. This can be seen in the nearby Andromeda galaxy which has stripped stars from its satellites M32 and NGC 205. It even appears to be syphoning off stars from the Triangulum galaxy, from a distance of a million light-years.

The same can be seen in our own Milky Way galaxy, which has numerous star streams and clusters that could be the remnants of dwarf galaxies slowly being digested.

The cannibalism of Andromeda and the Milky Way may serve as a common interest when the two galaxies meet, as they are expected to, in a few billion years. Perhaps they will slam together merging themselves like the Antennae, or perhaps they will dance around each other for a time, merging slowly and cautiously like the Mice galaxies. One thing we can know for sure: it will be a love affair of astronomical proportions.

—
1. Many of the interesting and bizarre types of stars and stellar phenomenon, like fuzzballs* and Quark stars* are purely hypothetical, or in rare instances theoretically confirmed only by the scantiest of evidence. My favorite is the preon star, a hypothetical star made up of a hypothetical type of particle known as preons. Seems like someone would confirm the preon’s existence before pretending things can be made out of it.

2. Yes, I know “holy shit” is a phrase, not a word.

More Information/Sources:
http://blogs.discovermagazine.com/badastronomy/2009/10/13/the-beauty-of-cosmic-collisions/
http://csep10.phys.utk.edu/astr162/lect/galaxies/colliding.html

The Whirlpool:
http://www.spacetelescope.org/images/html/heic0506a.html
http://usproxy.bbc.com/2/hi/science/nature/1263664.stm
http://apod.nasa.gov/apod/ap090526.html

The Antennae:
http://www.nasa.gov/multimedia/imagegallery/image_feature_1086.html
http://www.spacetelescope.org/news/html/heic0615.html
http://www.spaceref.com/news/viewpr.html?pid=25413

The Mice:
http://hubblesite.org/newscenter/archive/releases/2002/11/image/d
http://www.daviddarling.info/encyclopedia/M/Mice.html

The Cartwheel:
http://hubblesite.org/newscenter/archive/releases/1995/02/
http://apod.nasa.gov/apod/ap010612.html
http://csep10.phys.utk.edu/astr162/lect/galaxies/Cartwheel.html
http://www.spacedaily.com/reports/Cartwheel_Galaxy_Makes_Waves_In_New_NASA_Image.html

Cannibalism, Andromeda, and Milky Way:
http://www.space.com/scienceastronomy/astronomy/andromeda_010705.html
http://www.newscientist.com/article/dn17728-milky-ways-twin-caught-dismembering-neighbour.html
http://www.newscientist.com/article/dn14549-eleven-new-streams-of-stars-found-in-milky-way.html
http://www.spacedaily.com/reports/Sloan_Survey_Identifies_New_Dwarf_Galaxy_Inside_Milky_Way.html
http://www.guardian.co.uk/science/2009/jan/05/galaxy-collision-space-milky-way

M31-The Andromeda Galaxy on 10/18/09

It was very cold this evening, but the sky was clear and so I finally had a chance to try out my new imaging filter with my Nikon D50 camera. I decided to image the Andromeda Galaxy, M31 and I think it did a good job. I need to take some good flats to get the levelling right, but overall, I’m pretty pleased with the image.

Since it’s so popular right now, I give you: More Space Pictures! (as taken by NASA’s Hubble space telescope)

The Horsehead nebula:

M42 (a different view of the Orion Nebula):

The Rosette Nebula:

The Eta Carinae Nebula:

The Veil Nebula, sometimes called witch’s broomstick:

M31 galaxy (messier object 31, better known as the Andromeda Galaxy):

Seeing a bow, a demon,  and a few hundred billion stars  – meanwhile, Jupiter slams it into forward!

Please note: All charts with this post are for observers in mid-nothern latitudes centered on 40° N. If you are 10 or more degrees south or north of that – or if you’re not sure of your latitude – please go here to make your own custom star charts.

On tap this month is a new asterism,  the bow; a variable, Algol, the “demon star;” a neighboring galaxy you can see with the naked eye or binoculars; and yes, Jupiter, which appears to abruptly change directions as it moves against the background stars.

To begin our monthly exploration of the night sky, you can take a slide down Andromeda’s Couch to Mirfak and the Bow of Perseus in the northeast, assuming you learned these last month. If these are new to you, simply start by looking for the rising low in the northeast.

As usual, go out 45 minutes after sunset and watch the stars emerge. It may take another 15 minutes for  to see the bow  clearly, but what you are looking for is three stars in a vertical arc, with the middle one – Mirfak -  the brightest. How big an arc are we talking about? Just make a fist and hold it vertically at arm’s length, and your fist should just cover these three stars. How high? The bottom one should be about a first above the horizon.  Here’s a chart modified from Starry Nights Pro software..

Click chart for much larger view. If you observed last month you know the Great Square and Andromeda's Couch and can slide down the "Couch" to Mirfak, the brightest star in the bow of Perseus. If this is your first month of learning the sky, simply look to the northeast and find the bow.

Now if you want to be a stickler about mythology, Perseus doesn’t carry a bow – he wields a sword instead, which he is holding in his right hand high over his head, while in the left hand he holds the severed head of Medusa. Here’s how the 1822 “Urania’s Mirror” depicted it.

Perseus - click for alarger version.

Oh boy – and if you can see all that in these stars, then you have a very vivid imagination. I never would have learned the night sky if I had to try to trace out these complex constellations as imagined by ancient cultures and depicted in star guides up until fairly recently.  And for the purposes of helping you find your way around the night sky I think remembering the Bow of Perseus is easier. Mirfak, is just a tad dim to serve as one of our guidepost stars, but it does come in handy when identifying the “Demon Star,” whose proper name is Algol.

Getting sharp about brightness

As you start to learn the stars, it may surprise you how precise you can be about their brightness.  At first you may have difficulty just telling a first magnitude star from a second, but if you get to know Algol, the “Demon Star,” I bet you’ll find that you can quickly become quite sophisticated in assessing brightness and shaving your estimates down to a tenth of a magnitude.

Imagine a star that regularly varies in brightness every few days – that’s what Algol does. Exactly every 2 days, 20 hours and 49 minutes it begins a 10 hour period where its brightness dims more than a full magnitude. If you look during the right two hours, you’ll catch it at or near its dimmest – and most of the rest of the time you’ll catch it at peak brightness. And it’s quite easy to judge. But first let’s find it. Here’s the chart we’ll use.

Notice how Algol makes a very nice triangle with two companions, and all three stars are close to the same brightness – Almach, the bottom star in Andromeda’s Couch; Mirfak, the central star in the Bow of Perseus; and Algol. That brings us to our first challenge: Go out any clear night and study these three stars and decide which is the brightest. Two are equal in brightness, but one is a tad brighter than the other two. Which is it? Algol? Mirfak? Almach? (The answer is at the end of this text so you can ignore that answer until you actually have an opportunity to test yourself.)

However . . .

Because Algol is a variable, sometimes when you look at it, Algol will actually be significantly dimmer than either Mirfak or Almach. In fact, there’s a reasonable chance it will be dimmer than either of Mirfak’s two fainter companions that make up the Bow of Perseus. If when you test yourself, this is the case, congratulations! Make note of the date and time.

Algol is a special kind of variable star known as an eclipsing binary. That is, what looks like one star to us is really two stars, and when we see Algol’s light start to dim it means its companion is passing between Algol and us causing an eclipse. Since the stars are locked in orbit around one another this happens with clockwork regularity.

The above diagram came from this astronomy class web site which includes amore detailed scientific explanation.

Since either star of the pair can cause an eclipse, there is a much fainter, secondary eclipse of Algol – really too faint to be noticed by most observers. Why is one eclipse fainter – because one star is blue, Class B – and much hotter/brighter than the other star which is “K” class. (Remember – OBAFGKM.)  It is when the cooler star is in front that we see the dramatic change in light.

It’s fun to catch Algol in mid eclipse, but I suggest you not read about when to do this right now. Instead, do the little challenge first. Then when you’re ready, go to the final item in this, which explains how and when to catch Algol in eclipse and in the process, tells you the brightness of its companions.

OK – second project – Jupiter changes direction!

I described this in an earlier post an am quotingit in its entirety here.

The idea here is simple – connect what we can see in the sky this month with what’s actually going on. We’ll do this by watching Jupiter, the easiest object to find right now since it is the brightest “star” fairly high in the southeast shortly after sunset.

With just a few quick checks with binoculars we should be able to track the movement of Jupiter in relation to a bright, nearby star. You should start this project on or before October 1, 2009 if at all possible and plan to observe two or more nights between your start time and October 13. Then observe again in about a week and again near the end of the month.Your first couple of checks should show Jupiter in “retrograde” moving westward among the background stars. Your next two checks should show Juputer has resumed it’s normal eastward movement.

Use the following chart as both your guide and your log. That is, click on it to get a version you can print, take out under the stars, and record your observations on with a pencil.

So why does Jupiter appear to first go one way, then the other? Afterall, it isn’t really doing that, is it? Like the other planets – and us – it’s simply continuing a steady, eastward journey around the Sun. But so are we – and we are moving much faster because we’re much closer to the Sun. So what you are seeing is partly the movement of Jupiter – but also the apparent change in its position caused by our rapidly changing position.

I made the following animation from Solar System Live charts. It shows how Jupiter’s position changes slowly in relation to Earth and the other planets, particularly Neptune. The animation starts with September 1, 2009  and moves a month at a time for six months. The arrow shows our changing view of Jupiter with relation to Neptune, a much more distant – and even more slowly moving, planet. Notice that in late December Jupiter makes another close approach to Neptune – the third this year – which will make especially easy at that time to find this distant and faint planet. Right now you can use the chart above to track it down – it would be just visible in binoculars on a moonless night.

So let’s review the movements we’re dealing with here.

1. The daily rotation of the Earth causes Jupiter to appear to rise inthe east and move westward as the night progresses.

2. The revolution of the Eartha round the sun at a much higher speed than Jupiter makes it so that for some time the huge planet appears to be moving westward in relation to background stars and the more distant planet Jupiter. That apparent westward motion comes to a stop October 13, 2009.

3. Jupiter’s own motion is more apparent after October 13, as it appears to move eastward against the background stars. This general motion will carry it about 30 degrees eastward – very close to where Uranus can be found now – in about a year. It takes Jupiter almost 12 of our years to make a complete circuit of the sky.

The idea here is simple – connect what we can see in the sky this month with what’s actually going on. We’ll do this by watching Jupiter, the easiest object to find right now since it is the brightest “star” fairly high in the southeast shortly after sunset.

See a few hundred billion stars at one glance!

Yes, you can do it if you have good dark skies, you have allowed your eyes to dark adapt, and you are looking at the right place.  Once again, Andromeda’s Couch is our guide, and what we are looking for this time is the Great Andromeda Galaxy aka M31.

This is our “neighbor” in space if you can wrap your mind around the idea that something “just” 2.5 million light years away is a “neighbor.” ( As you try to do that remind yourself that a single light year is about 6 trillion miles – of course, good luck if you can imagine a trillion of anything!)

But seriously, you can see this with  your naked eye – and even in normal, light-polluted skies, you can see it with binoculars. In fact, this is one object where the binocular view can be almost as rewarding as the view through a telescope. Here’s a wide field chart for mid-month and about 90 minutes after sunset. At that point the galaxy should be roughly half way up your eastern sky.

Click image for larger version.

Starting with the preceding chart – and moving to the chart below:

1. Locate the Great Square
2. Locate Andromeda’s Couch off the northeast corner of the Square.
3. Go down to the middle star in the couch, then count up two stars and bingo!
4. You can also find the general vicinity by using the western end of the “W” of Cassiopeia as if it were a huge arrow head pointing right at the Andromeda Galaxy.

Click image for larger chart.

Well, “bingo” if you have been doing this with binoculars. With the naked eye it’s more an “oh yeah – I see it – I think!” But what do you expect? Think about it. The light from the near side of this object started its journey about 150,000 years before the light from the more distant side did! And think of where the human race was 2.5 million years ago when these photons began their journey – or for that matter, where all these stars really are today! Nothing is really standing still -everything is in motion.

You might also want to think about the folks who are on a planet orbiting one of those stars in the Andromeda Galaxy and looking off in our direction. What will they see? A very faint patch – probably fainter than what we see when we look at the Andromeda Galaxy, but in binoculars and telescopes roughly similar in size and shape.  Both Andromeda and the Milky Way Galaxy we inhabit are huge conglomerations of stars. We’re about 100,000 light years in diameter – Andromeda is about 150,000 light years in diameter. The Milky Way contains perhaps 100 billion stars – the Andromeda Galaxy maybe 300 billion.  (Don’t quibble over the numbers – even the best estimates are just estimates. )

And yes, in a few billion years we will probably “collide” with the Andromeda Galaxy, for we are hurtling towards one another. Such galaxy collisions are not that unusual  and probably aren’t as violent as the word “collision” makes them sound – but they do, in slow motion, bring about radical changes.

But all that is for the professional astronomers to concern themselves with – for us, there’s the simple beauty and awe of knowing that with our naked eye – or modest binoculars – we can let the ancient photons from hundreds of billions of stars ping our brains after a journey of millions of years.

And now the truth about Algol and companions

Have you done the Algol test yet? Looked at Algol, Mirfak, and Almach and tried to decide which is brightest? If so, you can check your answer by continuing to read. If not, I suggest you first do that exercise, then come back to this.

Chances are that when you look at Algol, it will be at its brightest – but how can you tell? Well, as we mentioned, you can compare it to Mirfak – but there’s an even closer match with another nearby bright star – Almach.  That’s the third star in Andromeda’s Couch  – the one neareast Algol.

Mirfak is the brightest of the three at magnitude 1.8.

Almach is magnitude 2.1 – the exact brightness of Algol when Algol is at its brightest – which is most of the time. OK – for the hair splitters, Almach is a tad dimmer, but the difference is far too little to be able to tell with your eye.

Here’s a chart showing the magnitude of the stars near Algol that you can use to compare it to and see if it is going through an eclipse.  People who look at variable stars use charts like this, but with one important exception – the numbers are given like they were whole numbers so you will not confuse a decimal point with another star. Thus, a star like Mirfak, of magnitude 1.8, would have the number “18” next to it. I broke a convention here because there are just a few bright stars on the chart, so I didn’t worry about the possible confusion of a decimal point being another star.

So If Algol and Almach are the same, no eclipse is going on at the moment.  If Algol appears dimmer than Almach, then an eclipse is in progress. If it’s as dim or dimmer than either of the companions of Mirfak in the Bow, then you can be pretty sure you’ve caught Algol at or near  its darkest. In two hours – or less – it will start to brighten and will return to full brightness fairly quickly.

Catching Almach at its dimmest is fun, but not as easy as it may seem. Why? Because although  an eclipse happens every few days, it may happen during the daylight hours, or in the early morning, or some other time when it’s inconvenient. And, of course, you need clear skies.  So when I want to observe an Algol eclipse, I go to a handy predicting tool on the Web that you can find here.

I then note the dates and times and pick out only those dates when the times are convenient to me – that is, happening during my early evening observing sessions. Then, given the  iffiness of the weather, I usually find that there are only one or two times a month when I’ll get a good look at an eclipse of Algol.

If I do this for October I find that out of 11 Algol minima, just three hit at the right time for me. Those dates and times are:

• 10/01/2009  9:09 pm EDT
• 10/21/2009  10:50 pm EDT
• 10/24/2009  07:39 pm EDT

Of course the dates and time may be different for you, depending on where you live, and none of us can escape the whims of the weather! So here’s hoping for clear skies for you so you can find a winking demon, follow the actions of Jupiter, and capture in your own eye the photos from a few hundred billion stars in the Andromeda Galaxy!

Ytterligare en bild på Andromedagalaxen, M31. Ovanför M31 ligger M11o. Klicka på bilden för en större  version.

• 17 september 2009
• Canon EOS 40D
• William Optics Zenithstar 80 ED APO & MkIII x.8 Reducer/Flattener (436 mm – f/5,44)
• Exponering 14 x 2 min.
• ISO: 800

Se trata de una de las galaxias más grandes y brillantes. Andrómeda pertenece al denominado “grupo local” que también integra la Vía Láctea, donde se encuentra la Tierra. Investigadores de la Sociedad Astronómica de España afirman que esta semana observarse con mayor claridad este espiral gigante.

El diario español “El País” publicó que la magnitud de la constelación es 3.4 y es visible a simple vista, aunque se encuentra a 2,5 millones de años luz. Los expertos afirman que se acerca al globo terráqueo a una velocidad de 140 kilómetros por segundo, por lo que existe la posibilidad de que dentro de unos 3.000 a 5.000 millones de años esta galaxia pueda colisionar con la nuestra.

Días atrás, por primera vez, un equipo de astrónomos trazó el mapa de las estrellas de Andrómeda, la cual se expande a gran velocidad al devorar a otras más pequeñas. Así lo publicó la revista “Nature” en su edición más reciente.

Con el empleo de un potente telescopio, los expertos midieron las inmensas fuerzas que absorben a la galaxia. Según el equipo, el estudio confirma el modelo jerárquico de formación de galaxias…[]

Fuente www.lagaceta.com.ar

NASA’s Swift satellite has acquired the highest-resolution view of the neighboring spiral galaxy M31. Also known as the Andromeda Galaxy, M31 is the largest and closest such galaxy to our own. It’s more than 220,000 light-years across and lies 2.5 million light-years away in the constellation Andromeda. Between May 25 and July 26, 2008, Swift’s Ultraviolet/Optical Telescope (UVOT) acquired 330 images of M31 at wavelengths of 192.8, 224.6, and 260 nanometers. The images represent a total exposure time of 24 hours. Some 20,000 ultraviolet sources are visible in the image, including M32, a small galaxy in orbit around M31. Dense clusters of hot, young, blue stars sparkle in the disk beyond the galaxy’s smooth, redder central bulge. Star clusters are especially plentiful along a ring about 150,000 light-years across.

http://www.nasa.gov/mission_pages/swift/bursts/uv_andromeda.html

AAS 211th Meeting: Star Formation Histories in the Andromeda Galaxy

Location: at home in Tomball, TX
Cloud cover: 0%
Transparency: above average (4/5)
Seeing: est. avg (3 or 4 out of 5)
Darkness: no moon, city glow
Wind: almost none (see below)
Temperature: 80º-85º
Humidity: 70%-85%
Dew Point: 72º-75º
Time: 9:00 pm – 1:00 am CDT
OTA: 8″ SC

Began with visual observation of Jupiter. Best view I have ever seen. Two main belts easily seen, two thin faint belts also visible in steadier seeing. All four Galilean moons visible: one left and three right.

Took photos of many targets using the D50. Most images had elongated stars varied in length and direction. In a couple of photos the stars are almost doughnut-shaped with dark centers. A few photos had no elongation, even at long exposures. Magnification shows elongated shapes are often irregularly shaped. My best explanation for the elongation is wind, although I felt no wind all night with only rare light gusts. Shutter is on 5 second timer. Perhaps I will try a longer timer next time.

Photos of M103 and M31 suffered from elongation. Photos of η Cas and Albireo (shown below) came out well. M76 was barely discernible even with a 30 second exposure at ISO 1600. Cat’s Eye Nebula (NGC6543) small, vivid teal, somewhat hazy — maybe from initial dew buildup that I didn’t recognize until much later.

Also took several photos of Jupiter and its moons, none of which were very good because of (as yet undiscovered) dew on the corrector. Several photos of Neptune and Uranus showed good color but no detail.

Albireo (β Cyg - double star). Click image for large (1500x1000) size.

A week ago, I got an Atlas non go to on lone from a buddy. Last night I got a chance to try it out and it did impress me. The mount is solid, tracking was good dispite the quick alignment. As kind of a test, I pointed the scope to M31, the Andromeda galaxy, piggy backed my modded 20D with a 70-200mm f/4L (non IS) lens and zoomed in to 200mm. At first I was going to do 15×2 minute exposures, but decided to double down and go for an hour. A few clouds changed the hour to 54 minutes, but the noise really cleaned up. I should of shot dark frames, but my battery died (which is another reason I did not make up those last 3 shots, and the moon was rising) and I was tired.

Andromeda galaxy, M31

So I loaded the files on my computer and did a quick and dirty stack and edit (with the help of  Noels Astro Tools) I came up with the image presented above. I must say, I expected more detail. Maybe I processed the image wrong. I know longer exposures would be better but I suspect at 3 minutes with the IDAS filter, the frame would be saturated with light pollution, so I may be at a wall here and galaxies and reflection nebula may have to wait till I am at dark skies and I will just have to stick with using the h-alpha filter from my back yard.

But on the bright side, I did manage to get out and do some astrophotography for the first time in several months.

A Mamyia anunciou três novos backs digitais para seu modelo médio formato 645AFDIII.

Os novos M18, M22 e M31 são baseados em sensores de 18MP, 22.1MP e 31.6MP, respectivamente, e incorporam LCD’s de 2.2″ com modo Live Preview.

Com a maior taxa de captura da linha (0.8 fps), o M18 tem sensor CCD de 44.2 x 33.1mm. O M22 traz um CCD maior, de 48.9 x 36.7mm, e o M31 também com as dimensões do primeiro porém com fotoreceptores de dimensões menores. Cada back pode ser comprado separadamente ou em um kit com a câmera (645AFDIII) e uma objetiva Sekor 80mm f/2.8 D.

Här kommer ett par bilder av Andromedagalaxen, en av våra galaxgrannar.

En vidvinkelbild på M31. En annan galax syns också på bilden, M33 – Triangelgalaxen, till vänster i bild.

• 10 januari 2005
• Pentax MX
• Objektiv: 50 mm – f/4
• Exponering: 10 minuter
• ISO: 800

Strax ovanför M31 syns en av dess satellitgalaxer: M110.

• 27 augusti 2006
• Pentax MX
• Objektiv: 200 mm – f/4
• Exponering: 20 minuter
• Film: Ektachrome E200

Tre satelliter passerade här.

• 22 september 2007
• Canon EOS 350D
• Objektiv: 100 mm – f/2,8
• Exponering: 4 x 3 minuter
• ISO: 400

• 10 oktober 2007
• Cnon EOS 350D
• Objektiv: 300 mm – f/4,5
• Exponering: 8 x 5 minuter
• ISO: 400

• 5 september 2008
• Canon EOS 40D
• Objektiv: 200 mm – f/4
• Exponering: 11 x 3 minuter
• ISO: 800

Närbild på M31. Strax under syns en annan galax, M32; och högst upp till höger syns M110.

• 29 september 2008
• Canon EOS 40D
• Primärfokus GSO 8″ (800 mm – f/4)
• Exponering: 3 x 2 minuter
• ISO: 800

Andromeda (including M31) on 1/24/09

Tonight I took a bunch of widefield shots tonight of part of the Andromeda constellation – you can see M31 – the Andromeda Galaxy in the upper right. For comparison, the image below is of the Andromeda galaxy through my 8″ telescope. It was taken a couple months ago.

M31 – The Andromeda Galaxy (through my telescope)

In three days, on wed 14/1/09, I won’t be an M31 employee anymore.
After 2 years of dedication, addiction, dreams and a lot of fun (thanks to all the lovely people in there, some of the best friends I’ve ever had!), I feel it’s the right time to move on.

Many thanks to all the cool people in there (the ones that make you smile, save your ass, drive you home, drive you mad, drive you crazy, teach you, kiss you, never betray you, and love you) and I wish all the best for M31 (that has been so kind to me during those years).

So.. thank you guys and remember that from 6pm to 9am I’m still a cool friend of you

Enrico

Artist's conception of what the Milky Way looks like from above the galactic plane. Click to enlarge and see labels.

Our galaxy, the Milky Way, appears to be about 50% more massive than we previously thought.  A team of scientists lead by Mark Reid of the Harvard-Smithsonian Center for Astrophysics have conducted a detailed 3-D survey of our galaxy and determined that it’s diameter is about 15% greater than previously believed and it is spinning more rapidly than had been thought.  The greater rotational speed indicates the presence of more mass, most of which is probably dark matter.

It is much harder to measure our own galaxy than those which are a million light years away because we’re embedded within it and can’t see the whole thing.

The Andromeda Galaxy, the most distant object you can see with your naked eye, will crash into our galaxy in about 2-3 billion years.

The new findings, which were presented today at the American Astronomical Society’s convention in Long Beach, California, mean that the Milky Way is about the same size as, not smaller than, our nearest large neighbor: the Andromeda Galaxy.  Andromeda, a.k.a. M31, may be larger in volume than our home galaxy, but appears to only be about the same mass, likely due to differing amounts of dark matter between the two bodies.

The new mass data has another implication for Milky Way-Andromeda relations: the anticipated collision between the two galaxies may now happen sooner than previously thought.  But don’t worry, it’s still 2-3 billion years in the future.  The Sun won’t go nova for about 5-6 billion years, so it will still be around, as will the Earth. However, the expansion of the Sun will make it impossible for liquid water to exist on the Earth’s surface in only one billion years.

The Mice Galaxies (so-called because of their appearance) are colliding and will likely form one larger galaxy, in many millions of years.

Galaxies collide are hardly unique occurrences in the universe.  When they do happen, the stars themselves don’t collide, they’re too far apart for that to be likely; however, a star or star system might be ejected from it’s galaxy or, less likely, the orbits of planets within a star system might be disrupted.  In any event, the gravity of the two galaxies will rip them apart until, millions of years later, they may form a new, bigger galaxy.  It is thought that the Andromeda-Milky War collision will form a large elliptical galaxy, which some have preemptively dubbed Milkomeda.

While you’re waiting for the collision, note that 2009 is the International Year of Astronomy.  Learn more about our endlessly fascinating universe by checking out some of the above links, or research any astronomical topics which are of interest to you.  It’s your universe—learn about it!

Las galaxias rara vez aparecen aisladas y su distribución en el Universo no es uniforme. Muchas se asocian en pares, tríos, grupos de algunas decenas o cúmulos de hasta algunos miles. Estos grupos se mantienen unidos por la gravitación.

Los cúmulos. Ya se conocen varios miles de cúmulos galácticos. Se clasifican en dos categorías principales. Los cúmulos ricos o regulares tienen una concentración central y una simetría esférica, con un predominio de galaxias elípticas o lenticulares. Los cúmulos pobres o irregulares no tienen concentración central ni simetría esférica, y contienen galaxias de todo tipo en proporciones variables. A su vez, los cúmulos se suelen concentrar em supercúmulos de hasta 100 millones de años luz de extensión. Así, se observa en el Universo una estructura jerarqizada en sistemas cada vez más extensos y menos densos, como lo había previsto a principios del siglo XX el sueco C. V. L. Charlier (1862- 1934).

El grupo local. Nuestra galaxia pertenece a un cúmulo de unas 30 galaxias, llamado Grupo local. Tiene una extensión máxima de 7 millones de años luz y una masa total estimada en 650 mil millones de veces la del Sol. Otras galaxias del Grupo local son la galaxia enana de Sagitario, nuestra vecina más cercana, y Dwingeloo 1, casi completamente oculta por la Vía Láctea, ambas descubiertas en 1994, así como la M31 de Andrómeda, una galaxia grande análoga a la nuestra, ubicada a 2,200,000 años luz (es el objeto celeste más lejano perceptible a simple vista). También pertenecen al Grupo local dos pequeñas galaxias irregulares que son satélites de la nuestra: la Nube Mayor de Magallanes (a 170,000 años luz) y la Nube Menor de Magallanes (a 200,000 años luz), visible en el Hemisferio Sur. El Grupo local está formado sobre todo por galaxias enanas. Los dos polos en torno de los cuales se concentran las otras galaxias del cúmulo son, por un lado, M31 de Andrómeda y M33 del Triángulo, y por el otro, nuestra galaxia.

Nuestra verdadera, gran e imaginable casa

Supercúmulos y vacío. En 1953, el astrónomo franco-estadounidense G. de Vaucoulerus estableció que el Grupo local y el conjunto de cúmulos cercanos forman parte de un sistema aplanado más amplio, con un radio de aproximadamente 50 millones de años luz. se llama Supercúmulo local y su centro es el cúmulo Virgo. Las observaciones recientes han demostrado la existencia de otros supercúmulos, entre los cuales hay grandes vacíos. La “Gran Muralla”, descubierta en 1989, es una estructura cósmica gigantesca que mide 500 millones de años luz de largo, 200 millones de años luz de ancho y 15 millones de años luz de espesor. La distribución a gran escala de las galaxias parece indicar que se concentran a lo largo de grandes estructuras filamentarias.

Estructura del Universo. El Universo podría tener una estructura celular parecida a la de espuma de jabón, con las galaxias dispuestas sobre las paredes de “burbujas” gigantescas, cuyo interior estaría prácticamente desprovisto de materia visible. el origen de esta impresionante estructura se remontaría a los primeros instantes despúes del Big Bang.