Into A Sea of Stars

 

The Universe That Wasn’t There

Growing up in a big city almost anywhere in the world breeds a certain disinterest in the sky. 

Observing stars in the night sky just isn't something big city people do, or fill any part of their busy lives thinking about. So for most of my childhood, which was in a corner of big city, I never really developed a feel for the the night sky. There was a bookish understanding of stuff up there. Planets were things that existed in text books. The sun moved between imaginary lines of tropics in diagrams of geography lessons. A school teacher once mentioned that সপ্তর্ষি মণ্ডল (the Bengali name for the Big Dipper in the Indian sky culture) was a constellation which looked like a question mark if one looked north at the dead of the night. I only had a vague idea of where "north" was - thanks to a tiny little compass tucked away in a drawer in my grandfather's writing desk. We lived in a bungalow style home wth an open terrace. During warm summer nights, especially with power cuts which were frequent then, my parents and I sometimes went up there to catch a cool breeze. I have vague memories of seeing the moon. But trying to find a constellation at an unearthly hour was an adventure too far. I had no idea where or how to begin. Then there was in a monthly magazine a series titled কালপুরুষ   ("Kalpurush") authored by a famous writer of the time. The title stood out as strange, mysterious and memorable in an awkward way. It literally translated to "temporal man". Though I had no idea what it really was about. I would later learn in the vedic constellation nomenclature, the name was a reference to Orion the hunter. But for that time, the universe lay perfectly hidden behind the everyday things we did in the pursuit of happiness.

Temporal Man 

In the four decades that passed, my own pursuits took me to major cities in India (Delhi and Mumbai) and thereafter to the United States. And eventually I had the good fortune of moving to the suburbs of New Jersey where light pollution had not fully enveloped the night skies and life at night was not a mad rush to get ready for the next day of work. With books, and then phone apps as a guide, I slowly taught myself how to read the night sky. Armed with an SLR and a pair of binoculars, I started my journey into the world of astrophotography - which would become my magic spell to lift the veil of darkness. And one of my first adventures would involve chasing Orion.

Stepping into a Sea of Stars

Somewhere between then and now, ten years had passed. This was a chilly February night with a few wispy clouds. I opened my front door for a "check in" on the universe before retiring for the night. Centered on the vaulted arch of my doorway was this starry humanoid figure majestically towering above me. Orion the hunter was by now a very familiar friend. Betelgeuse on its left shoulder, was visibly ruddy, as was Aldebaran, the eye of Taurus to the far right. There was also no mistaking Sirius the dog-star at its left foot. The bright "eye" aside - I could see the whole Canis Major constellation down to the dog’s tail. In my mind, for a moment every vestige of human settlement below faded away. I felt like I could take a step forward from the threshold of my home and dip into a sea or stars.

Hello Darkness

I had to pause to take a picture. This was a single shot with an SLR on a tripod. I threw in a clip-in light pollution filter to suppress the amber glow of sodium street lamps. A few tries later - I landed on this single 20 second exposure that did the trick. And after a little abracadabra on the computer - it was just  perfect.  Only in hindsight I realized that ten years after my first rendezvous, I had come a full circle standing face to face with the timeless “Temporal Man” again!

From being blind to a whole universe that lies hidden in plain sight, to being able to open the front door and step into a sea of stars - many of which I know by name - has been a long and rewarding journey into realms I did not imagine existed. And for that, I shall remain eternally grateful to life.

It's Raining Gems

 

While most major meteor showers originate from comets, the Geminids are among a few believed to originate from an asteroid. The source is the object called 3200 Phaethon. It is known as a "rock comet" since it had a trajectory like a comet but had no tail . The object was discovered by famous American Astronomer Fred Whipple who realized the object was connected to the meteor shower. Due to its close approach to the Sun, Phaethon is named after the character of Greek myth who drove the Sun-god Helios' chariot. 3200 Phaethon was discovered on Oct. 11, 1983, by the Infrared Astronomical Satellite..

A Geminid in Orion

My 2023 Geminid imaging setup included a DSLR mounted on a start tracker and set up for 3 nights in a row in my backyard with a self timer attached. Despite one lost day to a false start, the resulting composite shows seven Geminid meteors imaged over the nights of Dec 13th to 15th, 2023. The imaging duration spans the predicted peak night of Geminids in 2023.

The image on the left is a crop from the image above. This frames up a single Geminid meteor streaking across the constellation of Orion. It originated near Betelgeuse and travelled past the easternmost belt star, Mintaka. 

All images were taken using a stock Canon 70D DSLR on a tracked mount with a 11 mm ultra wide lens at its widest setting, ISO 800 and 10s exposure. No filters were used.

composite showing seven Geminid meteors imaged over the nights of Dec 13th to 15th, 2023. The imaging duration spans the predicted peak night of Geminids in 2023.

Last Sunset: The Final Bloom

 

Helix Nebula (Eye of God).
Credit: Purnendu Gupta

End of Days

Where do stars like the sun go when they die? At five billion years old, our sun is a middle aged star. It is also a middle class star, in the stellar spectral classification (yellow G type). When stars of this type reach the end of life, they do what humans do at the end of their working lives. They retire. 

That’s right. They do not explode into a supernova like their big brothers, or collapse into black holes like their superstar cousins. They gently walk into ... the sunset. And when they do, they leave behind what is known as a planetary nebula like the one you see in the image above. The Helix Nebula is also known as the Eye of God, for its unique shape. The nearest example of its kind, it is at about 650 light years distant in the constellation of Aquarius. The image above was shot from my backyard in November of 2022 and is light gathered over an hour and a quarter. The image below is a false-color composite of the same, in visible and invisible “light” as seen by four special purpose NASA telescopes that see in different wavelengths.

Helix Nebula, Composite X-Ray, UV, Optical, Infra Red Source: Nasa

Stars are nuclear fusion reactors that exist at a self adjusting balance between the inward pull of gravity and the outward pressure of hot fusing matter. A little bit like a balloon that exists at the sweet spot between the squishing pull of its skin, and the swelling push of the air inside.

A star first lights up when fusion is triggered in the core of the proto-star, among the simplest atom of all - primordial Hydrogen that have atomic number one. This is forced by enormous gravity to combine with its neighbor transforming into the next heavier element in the Periodic Table, Helium, with atomic number two.  As all hydrogen is exhausted, three of these Helium atoms will combine to form Carbon with atomic number six and so on. The nuclear alchemy goes on to magically cook heavier elements from lighter ones releasing energy in the process. 

About 12,000 years ago, the progenitor star of the Helix nebula started to run out of its hydrogen fuel. The star cooled some and lost some of its ability to hold itself up against gravity. The core shrank, and the outer layers slipped away from its grip into space cooling and expanding into a red giant. This was the end of the “middle class sun” phase of life of the star. Any planets in that solar system experienced the last sunset as the shell of expelled gas engulfed the inner planets just as our own sun would engulf Mercury, Venus and possibly the  Earth. 

The Star Within a Star

Once the outer veil got lifted what lay exposed was the star's stopped nuclear engine. While no longer undergoing fusion, it is held up by another force known as electron degeneracy pressure. A bright core made mostly of a soup of electrons, carbon nuclei and some other elements, on its way to becoming a white hot midget star - a white dwarf.

 

A white dwarf contains about half the mass of the original star but is compressed by gravity into a ball merely the size of the earth or only 1/100th of the sun’s original diameter. As a result the densities are enormous. A tea spoon could weigh as much as an average car on earth. For comparison, a spoon ful of the sun’s core would be much lighter at only 750 grams.

By the time the white dwarf forms, the expelled shell has not had time to go very far - and is perhaps a light year or two away from the core. Instead of being a perfect sphere, the expanding shell takes on beautiful shapes due to pre-existing asymmetries. The radiation from the white dwarf core lights up the expanding gas in concentric shells of colors. The Hydrogen glows red and the Oxygen glows blue and green. Like a cosmic flower in final bloom. While the “retired” white dwarf will last many tens of billions of years, the shells of the nebula around it will quickly fade away. 

Forget Me Knots

In 1996, a closer look into the Helix through the Hubble Space Telescope revealed some knot like structures, that were observed to lie in a ring pattern within the outer shell. These appear to be comet-like with a head and a tail pointing radially away from the core of the system. First discovered in the Helix, they were later found in many planetary nebulae. These knots were found to be the size of our solar system formed as the surrounding lighter gas got eroded and stripped back by the stellar wind and radiation from the central white dwarf forming finger like shapes due to a phenomenon known as the Rayleigh-Taylor instability. 

There are some theories that suggest that the origin of these knots may result from interactions of the progenitor star with its binary partner. But since the shell is only a couple of light years in diameter wide, the distances are perhaps too small for typical two star systems. Yet another theory suggests these could be remains of supersized comets the size of planets - the likes of which have not been seen before. A more likely explanation may have to do with remains of large planets that orbited the original star. As the star expanded to a red giant, these bodies may have continued to orbit "inside" the parent star. Over thousands of years, as the stellar wind and radiation from the white dwarf stripped away the lighter gas, all that remained are these comet like streams with the "tails" like little flags of existence. 

Was there life on any of these worlds? Evolution that spanned millions of years and civilizations that thrived for millennia? If so, these cometary knots may be the only signs that they were ever here.     

Imaging Specs:

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25x180s light frames (total 1 h 15 min integration) with calibration frames. Optolong L-enhance narrowband filter. ASI294MC Pro cooled camera. Guided exposure with Celestron 127 SLT Mak-Cass on AVX mount

References:

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The Hubble Helix Observations from stsci.edu

Cometary Knots in the Helix Nebula by O'Dell, C. R. & Handron, K. D., from Astronomical Journal, April 1996

A "FIREWORK" OF H2 KNOTS IN THE PLANETARY NEBULA NGC 7293 (THE HELIX NEBULA)  by M. Matsuura et al., from the Astrophysical Journal Published 2009 July 8

Further Reading:

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White Dwarf Star from Britannica. 

Iridescent Glory of Nearby Planetary Nebula Showcased on Astronomy Day from Hubblesite

HubbleMinute: Helix Nebula from Hubblesite (Video)

Ice Age Minds: The First Constellation

Taurus and Pleiades hang low on the western skies.
Seen from my backyard in March, 2023 

 

19,000 Years Ago

The darkness in the cave, was near perfect. In a little pool of light made by the faint glow of a tallow lamp, stood a man. In his hand was a piece of charcoal. His weathered fingers scratched the charcoal against the cave wall repeating strokes that created the outlines of the neck of an animal. Slowly, in the flicker of the lamp, the shape of a bull began to emerge. The horns, the eye, the hump. The air was filled with the odor of burning animal fat and strange sounds of men working on similar imagery. The distant sound of underground flowing water echoed through the cavernous tunnels some 50 feet underground - in Lascaux Caves, near the village of Montignac, modern day France. 

Some nineteen thousand years before present day, this would have been the creation scene of one of the most famous examples of upper paleolithic art.  Other panels depicting larger than life imagery of horses, deer, bisons, birds and humans that decorated the walls have fascinated researchers since their serendipitous discovery in 1940s. The artistic sophistication of these works from our ancestors rendered in charcoal and ochre have intrigued men. But even among this unique collection of ancient figures, bull number four in the Hall of the Bulls stands out. On the back of the animal, there are six dots that  look remarkably like a familiar shape in the night sky. The asterism Pleiades that is visible to the naked eye from all parts of the world. Placed above the hump of the bull it completes the picture of the star field in the modern constellation of Taurus.

Bull No. 4, Hall of Bulls, Lascaux, France

Ice Age Star Maps?

There have been several theories proposed by researchers on why prehistoric humans took such great pains to create the paintings in hard to reach locations untouched by natural light. These range from creating "art for art's sake" to the proposition that these were part of spiritual / religious rituals supposed to improve the chances of success at hunts which were critical to the survival of these men.

 

However a few researchers have proposed that the cave paintings were not just art but the most ancient star maps made by man. German researcher Dr. Michael Rappenglueck, of the University of Munich is the foremost among the proponents of this theory. According to him "It is a map of the prehistoric cosmos," ... "It was their sky, full of animals and spirit guides". In fact similar star maps have been discovered in ancient cave art in Spain, in Cueva di El Castillo cave, in the mountains of Pico del Castillo Dr. Rappenglueck has identified more constellations such as the Northern Crown. Many agree his findings and postulates are reasonable. 

So what was going on in the minds of these ancient artists of the ice age? Were the caves spiritual places like temples? Or were they planetariums of sorts?  Regardless of purpose, these ancient caves left their first explorers enthralled by a profound experience of reaching across time. In the words of the first explorers the Chauvet Cave in Ardeche France:   

"...Alone in that vastness, lit by the feeble beam of our lamps, we were seized by a strange feeling. Everything was so beautiful, so fresh, almost too much so. Time was abolished, as if the tens of thousands of years that separated us from the producers of these paintings no longer existed. ... Deeply impressed, we were weighed down by the feeling that we were not alone; the artists souls and spirits surrounded us..."

We may never fully know their minds. But if these were indeed star maps, and since constellations are figments of human imagination, bull number 4, in the Hall of the Bulls in Lascaux, may well have been Taurus, the first constellation to be ever recorded in the history of mankind. And today when we stand in our backyards and gaze at these enormous figures in the sky - we may feel a sense of kinship with early humans that once walked the earth..

Reference

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Ice Age star map discovered from BBC March, 2000

Virtual Tour of Lascaux

The Mind in the Cave - Consciousness and the Origins of Art, David Lewis - Williams

From Nova to Naught

 

Lady Luck called. But I wasn’t ready.

In fact I didn’t even recognize her since just as Thomas Edison predicted, she looked like work, dressed in overalls. 

On May 19, at 2 a.m. from my New Jersey backyard, I was testing my telescope tracking on an object I have never imaged before. The Pinwheel galaxy (Messier 101). The next day I heard that the 75 year old supernova hunter extraordinaire, Koichi Itagaki had done it again. Beating research grade observatories to the punch, he had reported a supernova in the same galaxy that very night.

I went back to check my images, and sure enough, amidst the wispy arms of the spiral, a new dot had appeared. An exploding star that outshone all its peers 21 million light years away. I had imaged a new supernovae only once before, a month after its discovery. But this time it was different. My time of capture was BEFORE that of Itagaki. More than 9 hours ahead.

“So you discovered it too.” My nine year old quipped, eyes slightly wider. 

“Nope.” I said. “Whoever reports it first gets credit.”

On a website that tracks these, there are 8 confirmed reports of others around the world who have reported imaging this pre-discovery, me included. None of them, was as prepared as Itagaki to confirm it’s appearance. 

So, what’s the lesson? 

When you see a lady in overalls, look again.

Else it may just be your chance of a lifetime coming to naught.

http://www.rochesterastronomy.org/sn2023/sn2023ixf.html

https://flic.kr/p/2oBJuNc

A "Smoking" Cigar

 

Cigar Galaxy (M82), May 12, 2023

One Eyed Wonder

The young man had only one good eye, yet he saw things no one had seen before.  

It was New Year’s eve, the year 1774. In the port city of Hamburg in what would become present day Germany, the 27 year old  astronomer was observing the night sky, about to make a discovery that would bear his name.

Seven

Venus and Pleiades put on a a little show in the western skies around 10 pm on April 13, 2023.This photo was taken near the date of conjunction when the planet is still very close to the asterism. The "seven sisters" of Greek mythology appear within arms reach from the rooftops and windows where earthlings go about their nightly lives, largely oblivious of the scene above. 

Ben Trovato

Winter Hexagon, March 20, 2023

A hunter raises his bow to take aim. Two hunting dogs at his feet give chase. An angry bull with enormous horns and a bloodshot eye charges forward.  A chariot rolls in, while a pair of twins, their hands entwined, tower above it all and keep watchful eye over the unfolding drama.

In late winter / early spring evenings this ancient tapestry of light covers a wide swath of south western sky stretching as far as the eye can see from the horizon up to the zenith. The scene in this image here is captured from my front porch on March 20, the day of the Vernal Equinox.

The Winter Hexagon

Six brightest stars in this patch of the sky, form the giant asterism known as the Winter Hexagon. Each star is part of its own constellation. For five of them, their distances in light years from the earth mirror stages of human life from childhood to old age.

In the Earth’s Shadow

Total lunar eclipse as seen on Tuesday Nov 8, from my backyard. Composite of 15 stills.

While partial lunar eclipses are relatively common, November 8, 2022 presented one of those rare occasions when my backyard lay in the path of totality. 

Lunar eclipses can be either simple or notoriously difficult to photograph depending on what one is trying to do. The last time I captured one was in 2021, and despite my best intents, I had slept through half of the occultation and managed to catch the second half of the event through the exit. This time the moon was supposed to set while fully eclipsed so there would be no such second chance. The next event visible in the Americas would not be until three years later in 2025. So though it was going to be cold, and the ungodly hour of four in the morning, I had to give it a shot. 

The Planets That Were Not

Animation of Jupiter's three nearest moons over 2.5 hours; Credit: Purnendu Gupta; Sep 26, 2022 

It was the night of January 7, 1610. A man in his mid forties stood in the back garden of his three story home in Padua, Italy. In his hand was his home made telescope pointed at the planet Jupiter.  He was the chair of mathematics at the university of Padua. Though well known by then, he had not quite become the icon that he would go on to be. Most of his remarkable achievements still lay in the future. But one that he would make over the next few days would etch his name in the history of astronomy forever.