Saúl Grijalva Varillas -Astrónomo Amateur

Meteor Borealis (APOD: 2024 Aug 16)
Image Credit & Copyright: Jason Dain
https://apod.nasa.gov/apod/ap240816.html

Explanation: A single exposure made with a camera pointed almost due north on August 12 recorded this bright Perseid meteor in the night sky west of Halifax, Nova Scotia, Canada. The meteor's incandescent trace is fleeting. It appears to cross the stars of the Big Dipper, famous northern asterism and celestial kitchen utensil, while shimmering curtains of aurora borealis, also known as the northern lights, dance in the night. Doubling the wow factor for night skywatchers near the peak of this year's Perseid meteor shower, auroral activity on planet Earth was enhanced by geomagnetic storms. The intense space weather was triggered by flares from an active Sun.

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Late Night Vallentuna (APOD: 2024 Aug 15)
Image Credit & Copyright: P-M Hedén (Clear Skies, TWAN)
https://apod.nasa.gov/apod/ap240815.html

Explanation: Bright Mars and even brighter Jupiter are in close conjunction just above the pine trees in this post-midnight skyscape from Vallentuna, Sweden. Taken on August 12 during a geomagnetic storm, the snapshot records the glow of aurora borealis or northern lights, beaming from the left side of the frame. Of course on that date Perseid meteors rained through planet Earth's skies, grains of dust from the shower's parent, periodic comet Swift-Tuttle. The meteor streak at the upper right is a Perseid plowing through the atmosphere at about 60 kilometers per second. Also well-known in Earth's night sky, the bright Pleides star cluster shines below the Perseid meteor streak. In Greek myth, the Pleiades were seven daughters of the astronomical titan Atlas and sea-nymph Pleione. The Pleiades and their parents' names are given to the cluster's nine brightest stars.

http://www.clearskies.se/
http://www.twanight.org/

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Meteors and Aurora over Germany (APOD: 2024 Aug 14)
Image Credit & Copyright: Chantal Anders
https://apod.nasa.gov/apod/ap240814.html

Explanation: This was an unusual night. For one thing, the night sky of August 11 and 12, earlier this week, occurred near the peak of the annual Perseid Meteor Shower. Therefore, meteors streaked across the dark night as small bits cast off from Comet Swift-Tuttle came crashing into the Earth's atmosphere. Even more unusually, for central Germany at least, the night sky glowed purple. The red-blue hue was due to aurora caused by an explosion of particles from the Sun a few days before. This auroral storm was so intense that it was seen as far south as Texas and Italy, in Earth's northern hemisphere. The featured image composite was built from 7 exposures taken over 26 minutes from Ense, Germany. The Perseids occur predictably every August, but auroras visible this far south are more unusual and less predictable.

https://www.instagram.com/wetter_eule/

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Giant Jet from the International Space Station (APOD: 2024 Aug 13)
Image Credit: NASA, Expedition 71 Crew, JSC, ESRS, Matthew Dominick; Processing: Simeon Schmauß
https://apod.nasa.gov/apod/ap240813.html

Explanation: What's that on the horizon? When circling the Earth on the International Space Station early last month, astronaut Matthew Dominick saw an unusual type of lightning just beyond the Earth's edge: a gigantic jet. The powerful jet appears on the left of the featured image in red and blue. Giant jet lightning has only been known about for the past 23 years. The atmospheric jets are associated with thunderstorms and extend upwards towards Earth's ionosphere. The lower part of the frame shows the Earth at night, with Earth's thin atmosphere tinted green from airglow. City lights are visible, sometimes resolved, but usually creating diffuse white glows in intervening clouds. The top of the frame reveals distant stars in the dark night sky. The nature of gigantic jets and their possible association with other types of Transient Luminous Events (TLEs) such as blue jets and red sprites remains an active topic of research.

https://www.nasa.gov/
https://www.nasa.gov/mission/expedition-71/
https://www.nasa.gov/johnson/
https://eol.jsc.nasa.gov/ESRS/
https://www.nasa.gov/people/matthew-dominick/
https://www.flickr.com/photos/semeion/

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Perseid Meteors over Stonehenge (APOD: 2024 Aug 12)
Image Credit & Copyright: Josh Dury
https://apod.nasa.gov/apod/ap240812.html

Explanation: What's happening in the sky above Stonehenge? A meteor shower: specifically, the Perseid meteor shower. A few nights ago, after the sky darkened, many images of meteors from this year's Perseids were captured separately and merged into a single frame. Although the meteors all traveled on straight paths, these paths appear slightly curved by the wide-angle lens of the capturing camera. The meteor streaks can all be traced back to a single point on the sky called the radiant, here just off the top of the frame in the constellation of Perseus. The same camera took a deep image of the background sky that brought up the central band of our Milky Way galaxy running nearly vertical through the image center. The featured image was taken from Wiltshire, England, being careful to include, at the bottom, the famous astronomical monument of Stonehenge. Although the Perseids peaked last night, some Perseid meteors should still be visible for a few more nights.

https://www.instagram.com/josh_dury_photomedia/

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Animation: Perseid Meteor Shower (APOD: 2024 Aug 11)
Visualization Credit: Ian Webster; Data: NASA, CAMS, Peter Jenniskens (SETI Institute)
https://apod.nasa.gov/apod/ap240811.html

Explanation: Where do Perseid meteors come from? Mostly small bits of stony grit, Perseid meteoroids were once expelled from Comet Swift-Tuttle and continue to follow this comet's orbit as they slowly disperse. The featured animation (here as a freeze-frame) depicts the entire meteoroid stream (in white) as it orbits our Sun. When the Earth nears this stream, as it does every year, the Perseid Meteor Shower occurs. Highlighted as bright in the animation, comet debris this size is usually so dim it is practically undetectable. Only a small fraction of this debris will enter the Earth's atmosphere, heat up and disintegrate brightly. Tonight and the next few nights promise some of the better skies to view the Perseid shower as well as other active showers because the first quarter moon will be absent from the sky from midnight onward.

http://www.ianww.com/
https://www.nasa.gov/
http://cams.seti.org/
https://www.seti.org/our-scientists/peter-jenniskens
https://www.seti.org/

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The Light, Dark, and Dusty Trifid (APOD: 2024 Aug 10)
Image Credit & Copyright: Robert Edelmaier and Gabriele Gegenbauer
https://apod.nasa.gov/apod/ap240810.html

Explanation: Messier 20, popularly known as the Trifid Nebula, lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. The reddish emission region, roughly separated into three parts by obscuring dust lanes, is what lends the Trifid its popular name. The cosmic cloud complex is over 40 light-years across and would cover the area of a full moon on planet Earth's sky. But the Trifid Nebula is too faint to be seen by the unaided eye. Over 75 hours of image data captured under dark night skies was used to create this stunning telescopic view.

https://www.astropicture.at/

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Las lágrimas de San Lorenzo

De acuerdo a la tradición cristiana, el 10 de agosto del año 258, San Lorenzo fue quemado vivo en una hoguera en Roma. Una muerte lenta en una parrilla. La leyenda cuenta que San Lorenzo llegó a decir mientras se quemaba: “Denme la vuelta que por este lado ya estoy hecho”

Las lágrimas de este martirio han pasado a la historia y son las que le dan el nombre a la lluvia de estrellas fugaces del verano; Las Perseidas.

Las Perseidas o lágrimas de San Lorenzo son la lluvia de estrellas fugaces más populares del año y alcanzan su máxima actividad en las noches de agosto. Si bien, Las Perseidas empiezan su actividad desde el 17 de julio y termina el 24 de agosto, alcanza su máximo la noche del 11 y madrugada del 12. El promedio normal de esta lluvia en su máxima actividad es de 50 a 75 meteoros por hora desde una zona rural.

Las partículas del las Perseidas que se incendian en la atmósfera provienen de los restos del cometa 109P/ Swift/Tuttle que va dejando a lo largo de su órbita cada que se acerca al Sol.
Se llaman Perseidas porque su radiante, la región del cielo de donde parecieran venir es la constelación de Perseo. La velocidad de estas partículas es de 60km/s y se queman a una altura de 80km sobre la superficie de la Tierra.

Desafortunadamente estamos en pleno monzón mexicano y los días nubosos son persistentes. Pero, si hay alguna oportunidad de ver esta lluvia, hay que salir a un área rural la noche del 11 y observar hasta la madrugada del 12. La Luna estará en un 44% de su totalidad. Hay que observar hacia cualquier dirección del cielo y esperar por esos trazos de luz. Es aconsejable ropa cómoda y fresca, mucho repelente, si es posible un camastro y, aunque no son necesarios, unos binoculares para aprovechar la vista del cielo de verano con la Vía Láctea en todo su esplendor.

Que tengan Cielos Claros!.

Saúl Grijalva Varillas
*************************
Imagen lluvia de estrellas: Canva AI generated
Imagen Santo: San Lorenzo (83 × 63 cm), obra de Bartolomé Esteban Murillo. Dominio público

A Perseid Below (APOD: 2024 Aug 09)
Image Credit: Ron Garan, ISS Expedition 28 Crew, NASA
https://apod.nasa.gov/apod/ap240809.html

Explanation: Denizens of planet Earth typically watch meteor showers by looking up. But this remarkable view, captured on August 13, 2011 by astronaut Ron Garan, caught a Perseid meteor by looking down. From Garan's perspective on board the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust from comet Swift-Tuttle. The vaporizing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is near frame center, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at a meteor shower? You're in luck, as the 2024 Perseid meteor shower is active now and predicted to peak near August 12. With interfering bright moonlight absent, this year you'll likely see many Perseid meteors under clear, dark skies after midnight.

https://www.nasa.gov/mission_pages/station/expeditions/expedition28/index.html
https://www.nasa.gov/

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Periodic Comet Swift-Tuttle (APOD: 2024 Aug 08)
Image Credit & Copyright: Gerald Rhemann
https://apod.nasa.gov/apod/ap240808.html

Explanation: A Halley-type comet with an orbital period of about 133 years, Comet 109P/Swift-Tuttle is recognized as the parent of the annual Perseid Meteor Shower. The comet's last visit to the inner Solar System was in 1992. Then, it did not become easily visible to the naked eye, but it did become bright enough to see from most locations with binoculars and small telescopes. This stunning color image of Swift-Tuttle's greenish coma, long ion tail and dust tail was recorded using film on November 24, 1992. That was about 16 days after the large periodic comet's closest approach to Earth. Comet Swift-Tuttle is expected to next make an impressive appearance in night skies in 2126. Meanwhile, dusty cometary debris left along the orbit of Swift-Tuttle will continue to be swept up creating planet Earth's best-known July and August meteor shower.

http://www.astrostudio.at/index.php

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¡Perseidas a la vista! 🌠

Llega la lluvia de meteoros más famosa del año, las perseidas. Este año alcanzan su máxima actividad en torno al 12 de agosto. 🗓️ Según avanza el fin de semana, podremos ver cada vez más meteoros. Al comienzo de la noche, la Luna en cuarto creciente 🌓 dificultará la observación de las estrellas fugaces más débiles. Por eso, este año es recomendable observar las perseidas a partir de la medianoche, cuando la Luna se haya puesto, para ver así un número mayor de estrellas fugaces. 👀

El radiante, el punto desde donde parecen surgir los meteoros, situado en la constelación de Perseo, alcanza una mayor altura sobre el horizonte de madrugada; esto contribuye a que tengamos una tasa de meteoros más elevada durante la segunda mitad de la noche. 🌌 Aunque es posible ver estrellas fugaces de esta lluvia desde finales de julio hasta bien avanzado agosto, esperamos que la actividad más intensa se concentre durante las noches del 11 al 12 y del 12 al 13 de agosto. 👀

Estas cautivadoras estrellas fugaces son, en realidad, minúsculos fragmentos del cometa Swift-Tuttle, que se queman al entrar en la atmósfera terrestre. ☄️ También son conocidas como «lágrimas de San Lorenzo» por la proximidad del máximo a esa festividad.

On the morning of August 13, 14, and 15 …
A slowly brightening Mars passes immediately north of the much brighter Jupiter. They already appear close to each other.

1. Look to the east 90 minutes before sunrise
on August 13, 14, and 15.
2. Find Mars and Jupiter shining left of the red star Aldebaran. Mars' brightness will nearly match that of Aldebaran.
3. Aim binoculars at Mars and Jupiter.
4. On the morning of August 14, they will be only 20 minutes apart.
5. They will be just 1.5º southwest of the open cluster NGC 1746.
6. A telescope at > 100 power will reveal Mars' tiny red disk and Jupiter's larger disk along with its four Galilean moons.

Milky Way Behind Three Merlons (APOD: 2024 Aug 07)
Image Credit & Copyright: Donato Lioce; Text: Natalia Lewandowska (SUNY Oswego)
https://apod.nasa.gov/apod/ap240807.html

Explanation: To some, they look like battlements, here protecting us against the center of the Milky Way. The Three Merlons, also called the Three Peaks of Lavaredo, stand tall today because they are made of dense dolomite rock which has better resisted erosion than surrounding softer rock. They formed about 250 million years old and so are comparable in age with the last great extinction of life on Earth. A leading hypothesis is that this great extinction was triggered by an asteroid about 10-km across, larger in size than Mount Everest, impacting the Earth. Humans have gazed up at the stars in the Milky Way and beyond for centuries, making these battlefield-like formations, based in the Sexten Dolomites, a popular place for current and ancient astronomers.

https://www.instagram.com/donamour_photography/
https://ww1.oswego.edu/physics/profile/natalia-lewandowska
https://www.oswego.edu/physics/

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Storm Cloud Over Texas (APOD: 2024 Aug 06)
Image Credit & Copyright: Laura Rowe (Used with permission)
https://apod.nasa.gov/apod/ap240806.html

Explanation: What makes this storm cloud so colorful? First, the cloud itself is composed of millions of tiny droplets of water and ice. Its bottom is almost completely flat -- but this isn't unusual. Bottom flatness in clouds is generally caused by air temperature dropping as you go up, and that above a specific height, water-saturated air condenses out water droplets. The shape of the cloud middle is caused by a water-droplet-laden column of air being blown upward. Most unusual, though, are the orange and yellow colors. Both colors are caused by the cloud's water drops reflecting sunlight. The orange color in the cloud's middle and bottom sections are reflections of a nearly red sunset. In contrast, the yellow color of the cloud's top results from reflection of light from a not-yet-setting Sun, where some -- but less -- blue light is being scattered away. Appearing to float above the plains in Texas, the featured impressive image of a dynamic cumulonimbus cloud was captured in 2021 while investigating a tornado.

https://laurarowe.smugmug.com/About-Laura-Rowe

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M27, the Dumbbell Nebula

M27 is considered by many observers to be the finest planetary nebula visible through small telescopes. The larger the telescope, the more detail is seen. It appears absolutely fantastic in large aperture instruments.

How to find M27:
1. Locate Cygnus and its southernmost star Albireo.
2. Find Vega and the Parallelogram of Lyra.
3. Draw a line from Gamma Lyrae, the southeastern star of the Parallelogram, to Albireo.
3. Extend that line for its same length. It ends on M27.
5. Through binoculars, M27 resembles a dim round smudge.

M27 through a telescope:
• Use a 6 inch or larger telescope.
• View at >100 power.
• Note the northern and southern lobes.
• Use a UHC filter or an OIII filter.

https://youtu.be/xbPZR0MkPrM

Milky Way Over Tunisia (APOD: 2024 Aug 05)
Image Credit & Copyright: Makrem Larnaout
https://apod.nasa.gov/apod/ap240805.html

Explanation: That's no moon. On the ground, that's the Lars Homestead in Tunisia. And that's not just any galaxy. That's the central band of our own Milky Way galaxy. Last, that's not just any meteor. It is a bright fireball likely from last year's Perseids meteor shower. The featured image composite combines consecutive exposures taken by the same camera from the same location. This year's Perseids peak during the coming weekend and is expected to show the most meteors after the first quarter moon sets, near midnight. To best experience a meteor shower, you should have clear and dark skies, a comfortable seat, and patience.

https://www.astrobin.com/users/Makrem_Larnaout/

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Astronomical League’s Featured Double Star for August!

Glory and Fog Bow (APOD: 2024 Aug 03)
Image and Video Credit & Copyright: Cem Özkeser and Yasin İlcebay
https://apod.nasa.gov/apod/ap240803.html

Explanation: On a road trip up Mount Uludağ in Bursa province, Turkey these motorcyclists found themselves above low clouds and fog in late June. With the bright Sun directly behind them, the view down the side of the great mountain revealed a beautiful, atmospheric glory and fog bow. Known to some as the heiligenschein or the Specter of the Brocken, a glory can also sometimes be seen from airplanes or even high buildings. It often appears to be a dark giant surrounded by a bright halo. Of course the dark giant is just the shadow of the observer cast opposite the Sun. The clouds and fog are composed of very small water droplets, smaller than rain drops, that refract and reflect sunlight to create the glory's colorful halo and this more extensive fog bow.

https://cemozkeser.com/about/

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Mars Passing By (APOD: 2024 Aug 02)
Image Credit & Copyright: Tunc Tezel (TWAN)
https://apod.nasa.gov/apod/ap240802.html

Explanation: As Mars wanders through Earth's night, it passes about 5 degrees south of the Pleiades star cluster in this composite astrophoto. The skyview was constructed from a series of images captured over a run of 16 consecutive clear nights beginning on July 12. Mars' march across the field of view begins at the far right, the planet's ruddy hue showing a nice contrast with the blue Pleiades stars. Moving much faster across the sky against the distant stars, the fourth planet from the Sun easily passes seventh planet Uranus, also moving across this field of view. Red planet Mars and the ice giant world were in close conjunction, about 1/2 degree apart, on July 16. Continuing its rapid eastward trek, Mars has now left the sister stars and outer planet behind though, passing north of red giant star Aldebaran. Mars will come within about 1/3 degree of Jupiter in planet Earth's sky on August 14.

http://www.twanight.org/tezel
http://www.twanight.org/

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Esta semana...

Disfrutando del cielo la primera quincena de agosto 🌌

Si miras el cielo al anochecer durante la primera quincena de agosto, verás a la Luna creciente viajar por el sur. 🌒 Además, verás a Venus subir lentamente por el oeste. El lucero vespertino ha venido para quedarse, y acompañará nuestros anocheceres durante el resto del año. 🌟

Aprovecha los amaneceres de esta quincena para ver algunas de las constelaciones favoritas de los aficionados: Orión, Géminis y Tauro. Además las madrugadas del 12-13 podrás ver el máximo de las perseidas 🌠, y el día 14 una conjunción Marte-Júpiter. ¡No te lo pierdas!

Leopard Spots on Martian Rocks (APOD: 2024 Jul 31)
Image Credit: NASA, JPL-Caltech, MSSS, Perseverance Rover
https://apod.nasa.gov/apod/ap240731.html

Explanation: What is creating these unusual spots? Light-colored spots on Martian rocks, each surrounded by a dark border, were discovered earlier this month by NASA's Perseverance Rover currently exploring Mars. Dubbed leopard spots because of their seeming similarity to markings on famous Earth-bound predators, these curious patterns are being studied with the possibility they were created by ancient Martian life. The pictured spots measure only millimeters across and were discovered on a larger rock named Cheyava Falls.

https://www.nasa.gov/
https://www.jpl.nasa.gov/
https://www.msss.com/
https://science.nasa.gov/mission/mars-2020-perseverance/

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Asterisms in Sagittarius

Have fun with Sagittarius. Make it yours!

Sagittarius is found very low in the south-southeast in the early evening in July, south in August, and south-southwest in September. Look for the Teapot shape. The rest extends southeast.

• Can you spot the Teapot with steam (Milky Way star clouds and nebulae) rising out of its spout?
• Can you trace the Tea Spoon and the Milk Dipper?
• How about the lesser known Ice Tea Spoon? (More suitable than a teaspoon for summertime tea.)
• And Herman's Cross in far eastern Sagittarius consisting of three 4.5 magnitude stars and the 4.7 magnitude Omega Sagittarii?

Leopard Spots on Martian Rocks (APOD: 2024 Jul 31)
Image Credit: NASA, JPL-Caltech, MSSS, Perseverance Rover
https://apod.nasa.gov/apod/ap240731.html
Repost with zoomed in image

Explanation: What is creating these unusual spots? Light-colored spots on Martian rocks, each surrounded by a dark border, were discovered earlier this month by NASA's Perseverance Rover currently exploring Mars. Dubbed leopard spots because of their seeming similarity to markings on famous Earth-bound predators, these curious patterns are being studied with the possibility they were created by ancient Martian life. The pictured spots measure only millimeters across and were discovered on a larger rock named Cheyava Falls.

https://www.nasa.gov/
https://www.jpl.nasa.gov/
https://www.msss.com/
https://science.nasa.gov/mission/mars-2020-perseverance/

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Comet Olbers over Kunetice Castle (APOD: 2024 Aug 01)
Image Credit & Copyright: Petr Horálek / Institute of Physics in Opava
https://apod.nasa.gov/apod/ap240801.html

Explanation: A visitor to the inner solar system every 70 years or so Comet 13P/Olbers reached its most recent perihelion, or closest approach to the Sun, on June 30 2024. Now on a return voyage to the distant Oort cloud the Halley-type comet is recorded here sweeping through northern summer night skies over historic Kunetice Castle, Czech Republic. Along with a broad dust tail, and brighter coma, this comet's long ion tail buffeted by storms and winds from the Sun, is revealed in the composite of tracked exposures for comet and sky, and fixed exposures for foreground landscape recorded on July 28. The comet is about 16 light-minutes beyond the castle and seen against faint background stars below the northern constellation Ursa Major. The hilltop castle dates to the 15th century, while Heinrich Olbers discovered the comet in 1815. Captured here low in northwestern skies just after sunset Comet Olbers, for now, offers skywatchers on planet Earth rewarding telescopic and binocular views. Comet 13P/Olbers next perihelion passage will be in 2094.

https://www.petrhoralek.com/ -1
https://www.slu.cz/phys/en/

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