Twinkle Twinkle Little Star: BGP's Astronomy Thread

Page 6 of I'm sure there are several astronomy enthusiasts here, besides TB&G and myself. I can't get enough of astronomy and I never get tired of learning n... 117 comments | 2131 Views | Go to page 1 →

  1. #76
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    The August eclipse will be incredibly accessible to anyone within a 200-mile drive of its path of totality, but the most important factor in getting a good view is weather.

    But if you’re hoping to make a trip out of the big event, Greatamericaneclipse.com has a list of 10 great places to see the phenomenon based on the best weather odds for clear skies:

    Madras, Oregon: Totality begins at 10:19 a.m. PDT and lasts 2 minutes and 4 seconds.

    Snake River Valley, Idaho: Totality begins at 11:33 a.m. MDT and lasts 2 minutes and 18 seconds.

    Casper, Wyoming: Totality begins at 11:42 a.m. MDT and lasts 2 minutes and 4 seconds.

    Sandhills of western Nebraska: Totality begins at 11:49 a.m. MDT and lasts 2 minutes and 30 seconds.

    St. Joseph, Missouri: Totality begins at 1:06 p.m. CDT and lasts 2 minutes and 39 seconds.

    Carbondale, Illinois: Totality begins at 1:20 p.m. CDT and lasts 2 minutes and 41.6 seconds.

    Hopkinsville, Kentucky: Totality begins at 1:24 p.m. CDT and lasts 2 minutes and 41.2 seconds.

    Nashville, Tennessee: Totality begins at 1:27 p.m. CDT and lasts 1 minute and 57 seconds.

    Great Smoky Mountains National Park: Totality begins at 2:35 p.m. EST and lasts 1 minute and 17 seconds.

    Columbia, South Carolina: Totality begins at 2:43 p.m. EST and lasts 2 minutes and 30 seconds.
    Advertisement

  2. #77
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Here are the times from beginning of eclipse til end of eclipse for some cities in the path of totality:

    Name:  tableeclipse.png
Views: 27
Size:  41.8 KB

  3. #78
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Name:  eclipse path.jpg
Views: 25
Size:  230.5 KB

  4. #79
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Totality, much like most precious moments in our lives, is very fleeting. Totality will last what will seem like for only seconds(2 min, 40 sec will be the max., depending on where you view from). As I said above, I want you to take in the entire eclipse experience. Engage your senses and pay attention not only to the black hole in the sun but everything around you.

    Don't get me wrong, the Sun's Corona is the star of the show !!! Make sure you check it out. If you have binoculars or a telescope, all the better. But don't miss out on all those going on around you. Live the experience!!!! It may be the only chance you will get.

    Now, everything that I mention below is only gonna be relevant if you are inside the Moon's dark umbral shadow. So, I strongly encourage you to do whatever you can to get to a location where you are in the path of totality. You wouldn't think so but there will be quite a difference in your experience if you are in a 96% band versus the path of totality. Take off work, play hooky from school, drive a couple hundred miles if you have to, but GET TO TOTALITY on August 21 !!! You won't regret it. It's been 38 years since we had a total eclipse over parts of the contiguous US and it's been 99 years since we had this large a swatch of the US kissed by this kind of Sun-Moon shadow dance. So enjoy this rare celestial show!!!

    You are going to experience quite the overload of sensory stimulation. This is a celestial phenomenon that truly will overwhelm your senses!!!! Be prepared and soak it in !!! Remember totality will be fleeting, so try not to miss anything. Remember also that you must use a safe solar filter to observe the eclipse if any part of the sun is visible. Else, you risk permanent eye damage or even blindness. Only during the two minutes or so of totality can you can you safely view the eclipse without a filter.

    Here's some things I'm going to watch for and experience and I want every BGP'er to do the same:
    ************************************************** ****************

    First Contact: The Eclipse Begins The Moon touches the Sun and takes its first tiny nibble out of the solar disk. First contact is initially visible through a telescope, then in binoculars, and finally with the unaided eye. Regardless of how you view it, observing with a safe solar filter is an absolute must.
    The Vanishing Sun: During the next hour or so, the Moon hides more and more of the Sun. It’s a leisurely affair, so you have plenty of time to look around. As the eclipse progresses, can you detect any change in the color and quality of the sky, the clouds, nearby objects, and distant landscapes?
    Changing Light: Once more than half the Sun is covered, the light begins to fade, though imperceptibly at first. About 15 minutes prior to totality, the light becomes noticeably dimmer and starts to take on an odd or eerie “tint.” Shadows become sharper and more detailed. Look away from the shrinking solar crescent — has there been a change in the color of the sky and clouds since the eclipse began?
    Sharpening Shadows: As the Sun dwindles to a thin crescent, shadows become much sharper. Look at your own shadow — notice how you can see the shadows of individual hairs on your head or arms.
    Animal and Human Behavior: As the sunlight dims, you may spot the local fauna acting in a peculiar manner. Many start to settle in as if night is falling. Notice the people around you — they’re likely more animated than any local wildlife!
    Weather: As totality nears, you may notice a perceptible drop in the temperature, and the wind may pick up or change direction.
    Deepening Darkness: Look west a few minutes before totality. Can you see the oncoming umbral shadow? Clouds on the horizon will go dark as the Moon’s shadow sweeps over them, making the approaching umbra more noticeable.

    Shadow Bands: Very dim, undulating ripples of dark and light might appear, flowing across the ground or the side of a white building. These hard-to-see features are caused by atmospheric refraction of the thin solar crescent just prior to second contact and/or immediately after third contact.
    Emerging Corona: Some 30 seconds before totality, cover the shrinking solar crescent with your outstretched thumb and remove your eclipse viewers. You’ll likely spot the Sun’s corona (its outer atmosphere) on the side opposite the crescent. But if you do this, you might miss the next two events!
    Baily’s Beads: Just prior to totality, all that remains of the Sun are a few shafts of light shining through deep valleys on the lunar limb (edge). The result is a few brilliant beads that disappear one after another. If you’re using a telescope or binoculars to observe the beads, keep your solar filters on. If not, take the filters off once the number of beads dwindles to two.
    Diamond Ring: The lunar shadow envelops you. Only a single bead remains — it shines like a brilliant diamond set into a pale ring created by the pearly white corona surrounding the Moon’s black silhouette. Filters off!
    Second Contact: Totality Begins! The last bead vanishes, the solar surface is hidden, and the Sun’s ghostly, gossamer corona glows around the black lunar silhouette. Feel free to scream and yell in delight, or just stare in silent awe.
    Chromosphere and Prominences For a brief time after the start of totality, the Sun’s chromosphere (thin middle atmosphere) remains visible along the solar limb (edge) still being covered by the advancing Moon. This vivid arc of red vanishes quickly, so don’t miss it. Depending on how active the Sun is, you may spot several streamers of red stretching up from the chromosphere into the corona. These are solar prominences, and they, too, soon disappear behind the encroaching lunar limb.


    The Corona :Now’s the time to explore the solar corona, the star of the show. Using just your eyes, take a few moments to carefully study the appearance of the corona near the Sun. Can you detect any color? Does the corona look smooth or mottled? Use averted vision (stare at the eclipsed Sun, but concentrate your attention on the corona streaming away from either side of the Sun) to determine how far east and west the faint, outer corona extends. Is it rounded or elongated? Now use binoculars or a telescope to check out detail within the corona. Look for loops and arcs that reveal solar magnetic fields, and compare the structure of the corona at the Sun’s poles and equator (it’s often quite different).
    Planets and Stars: Brilliant Venus will likely be visible even before totality. Some of the other planets (notably Jupiter and perhaps Mars and Mercury too) and a few bright stars (notably Regulus, in Leo) might put in an appearance. But don’t spend too much time looking for them — totality is fleeting!
    Sky and Horizon: Sky darkness during totality varies from eclipse to eclipse. How dark it gets depends on the Moon’s angular size, the presence or absence of clouds, and how close your site is to the centerline. Just outside the path of totality, the Sun is still shining, albeit dimly. This feeble light creates a beautiful 360 sunrise/sunset glow around the horizon. Don’t miss it.
    Experience Totality: Beware of spending totality with your eye glued to your camera’s viewfinder. Taking pictures is fine, but make sure you take time to appreciate what is truly a total sensory spectacle. If you’re using a telescope to examine the stunning detail in the corona, pause for a few moments, look away, and absorb the surrounding vista.


    Totality’s Finale: Yes, both the sky and the edge of the corona opposite where the Sun vanished really are a little brighter now. Fingers of red (prominences) slowly rise from behind the Moon’s retreating limb. They are soon joined by an emerging arc of red light — the chromosphere. The end of totality is imminent.
    Third Contact: Diamond Ring One blazingly bright bead of sunlight erupts into view. Totality is over. Solar filters on! The stages of the eclipse now repeat in reverse order.
    Baily’s Beads: More rays of sunlight burst through lunar valleys and quickly combine to form a very thin crescent. The solar crescent rapidly expands, and the sky brightens quickly. If you want a few more seconds of corona viewing, block the emerging Sun with your thumb.
    Shadow Bands: These dim ripples of dark and light may appear briefly while the solar crescent remains extremely thin.
    Retreating Shadow: If you’re not busy watching for shadow bands or squeezing in a few more seconds of corona viewing, quickly look away from the emerging Sun. Can you see totality’s wave of darkness speeding rapidly into the east?
    Temperature: The temperature will likely continue to cool slightly after totality concludes and begin to rise shortly thereafter. However, the change may be subtle and could be masked by a shift in wind speed and direction.
    Animal and Human Behavior: As the Sun emerges, so too will any wildlife that, as totality approached, decided something odd was happening and started to go to sleep. Meanwhile, your eclipse-watching companions will be happily chatting among themselves, comparing images, and probably ignoring the returning solar disk.
    Sharp Shadows: While the Sun remains a thin crescent, shadows are much sharper than usual. If you forgot to look at your own shadow on the ground before totality, be sure to look now — you'll see crisp shadows of hairs on your head or arms.
    The Returning Sun: Just as it took a while for the Moon to cover the Sun, it will take an equally long interval — more than an hour — for the Moon to move off the solar disk. (The time between third and fourth contact will seem much, much longer than between first and second contact!) But don’t lose track of time — you’ll want to witness the official end of the eclipse.
    Fourth Contact: The Eclipse Ends: The last tiny indentation on the Sun disappears, and the Moon no longer covers any part of the solar surface. The eclipse is officially over.

    If you take the time to experience, and not just observe, this rare celestial phenomenon on the 21st of August, I think you will agree with me that it was almost a spiritual experience. Our connection to the cosmos is a very spiritual thing for me. Every atom in each our bodies came from the inside of some exploding star. We are all intimately connected to the cosmos--- we are all made of stardust!!!!
    Experience that connection next month. Be blessed.
    Last edited by Science Friction; Jul 15, 17 at 05:30 PM.

  5. #80
    The Professor's Avatar
    Join Date
    Jan 04
    Location
    Sag Hollow
    Posts
    19,671

    I think my family will be heading to Cookeville, TN to view the totality. That's the closest from where I live, about 180 miles.the 100% totality is just slightly south of Cookeville. Should be close to 2 minutes of darkness.

  6. #81
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Quote Originally Posted by The Professor View Post
    I think my family will be heading to Cookeville, TN to view the totality. That's the closest from where I live, about 180 miles.the 100% totality is just slightly south of Cookeville. Should be close to 2 minutes of darkness.
    That's terrific!!! I'm excited that you will be viewing totality.

  7. #82
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Enhanced color image of Jupiter's Great Red Spot from the Juno flyby last Monday:

    Name:  red spot.jpg
Views: 20
Size:  122.5 KB

  8. #83
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    And another from last week's flyby:

    Name:  red spot2.jpg
Views: 20
Size:  59.7 KB


    Spacecraft was about 6,130 miles from the tops of the Jovian giant's clouds when this image was taken.
    Last edited by Science Friction; Jul 17, 17 at 06:46 PM.

  9. #84
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Juno reached perijove last Monday at 9:55 EDT, at which time it was just 2,200 miles above Jupiter's cloud tops. Btw, perijove is a term for astronomy nerds like me and it means the point at which the spacecraft's orbit came closest to Jupiter's center.

    Eleven min and 33 sec after reaching perijove, Juno had covered another 24,713 miles , and was passing directly above the coiling, crimson cloud tops of the Great Red Spot. The spacecraft passed about 5,600 miles above the clouds of this iconic feature.

  10. #85
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Btw, for those interested in such things, the Great Red Spot measures about 10,159 miles wide and is about 1.3 times wider than the planet we call home. This giant storm has been monitored by scientist since 1830(though earlier astronmers reportedly saw a red spot , as well). So, I'd say that this storm may have been raging for 350 years or more. In modern times, however, the GRS appears to be shrinking in size.

  11. #86
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Indian astronomers have recently identified a supercluster of galaxies that was previously unknown. They named the superstructure "Saraswati," after a Hindu goddess. This giant superstructure of galaxies, visible in a large spectroscopic survey of distant galaxies, was quite a surprise to its star-gazing discoverers.

    A supercluster is a chain of galaxies and galactic clusters that are bound by gravity and stretch for hundreds of times the size of clusters containing for tens of thousands of galaxies. So, if you do the math you can see just how many galaxies are contained within these superstructures. Specifically, the newly-discovered Saraswati supercluster extends over 600 million LY and likely contains the mass equivalent of more than twenty million billion suns . That's 20,000,000,000,000,000 suns!!!!

    Of course, when we peer into deep space, we look back in time. In the case of this supercluster, which is 4 billion LY away, astronomers are seeing Saraswati when the universe was ten billion years old.

    Most interesting for me is that the discovery of this giant supercluster will force astronomers to re-think popular theories of how the universe got its present form since most forms of the cold dark matter model of the evolution of the universe do not predict the existence of giant structures such as Saraswati within the current age of the universe.

    Saraswati supercluster :

    Name:  saraswati.jpg
Views: 19
Size:  36.0 KB

  12. #87
    Runcible Owl's Avatar
    Join Date
    Apr 17
    Location
    Above ground? Excellent!
    Posts
    278

    @Science Friction - thanks for the follow up on the GRS. Saraswati fascinating. Will be doing a little light year reading later tonight. Great work as always.

  13. #88
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    Quote Originally Posted by Runcible Owl View Post
    @Science Friction - thanks for the follow up on the GRS. Saraswati fascinating. Will be doing a little light year reading later tonight. Great work as always.
    Thank you so much. I appreciate you reading.

  14. #89

    Join Date
    Nov 15
    Posts
    1,701

    We are planning to make the trip to Hopkinsville, if I can travel that far. I'm counting on it. Rooms are already impossible close by. Thanks for all the info, S.F.

  15. #90
    Science Friction's Avatar
    Join Date
    Apr 13
    Location
    "Every atom in our bodies came from a star that exploded. The atoms in your left hand probably came from a different star than your right hand. We are all stardust."
    Posts
    6,989

    A huge sunspot erupted from the sun on July 14th just as the spot faced Earth. The massive sunspot, AR2665, is 75,000 miles wide in diameter. The eruption was in the form of a M2.4 long solar flare and it produced a CME(Coronal Mass Ejection) that bombarded Earth's atmosphere on Sunday the 16th at 6:01 UTC . A G2(Moderate) level geomagnetic storm began about nine hours later.

    Shortly after the July 14 eruption, NOAA's Space Weather Prediction Center had issued a Geomagnetic Storm Watch for Sunday night through Monday for a G2 level storm, which is considered a moderate storm. They use a scale from 0-5 to rate solar storms.

    By the time darkness had had settled in North America Sunday night and the aurora could be seen, the storm was in its waning stages. Still, some vibrant green and purple lights were seen in the higher latitudes of the US and in Canada.

    Here's what the July 14 eruption of that Sunspot produced Sunday night:

    West Vancouver, British Columbia:

    Name:  westvancouverlights.jpg
Views: 10
Size:  48.5 KB

    Nova Scotia:
    Attached Images Attached Images  

Top