Comet Neowise from a Chennai terrace part 2

Author: Ravi Kailas (ficustours@gmail.com)

After making a post on my first sighting of Comet Neowise, on Thursday, 23rd July, the sky was clear enough (relatively speaking, but not before a typically dramatic (see video below), July evening cloud build-up in the western sky, threatening a black-out) for another attempt at imaging the comet, on Friday, 24th July. 

While, in the earlier post, I might have suggested that this comet is comparable to Hale-Bopp, that visited three decades ago, I understand that it is barely (although higher in the sky) a naked eye object of late, with a visual magnitude of over 7 (unlike in early July, while it was, reputedly, much brighter in morning sky) and its fuzzy spread of light (unlike pin-point sources like stars), makes it all the more difficult to spot without visual aids. Light polluted city skies, as in Chennai, with veil of high clouds, and additional light from the first quarter moon, do not particularly help matters either and it required a bit of effort, looking through binoculars in the section of the sky, west of Ursa Major, before I can locate a faint greenish-blue blob, with vestiges of a tail. Fortunately these conditions stayed, more or less the same, through a prolonged imaging effort (for an hour or so from about 1920), and I managed a series of multiple images, with a combination of settings (see table below and associated images), all untracked, with an m43 camera (Olympus O-MD E-M5II) and a M. Zuiko 40-150 2.8 lens. 

Image no.     Focal Length                     Settings

1                    150mm                                     ISO 1250 2.5s f 2.8 Stack of 21 Images

2                    150mm                                     ISO 3200 1.6s f 2.8 Stack of 21 images

3                    150mm                                     ISO 1600 3.2s f 2.8 Stack of 18 Images

4                    150 mm                             ISO 2000 1.6s f 2.8 Stack of 21 Images

While the results, after much post processing (alignment and stacking to start with) with Lightroom 6.0 and Nebulosity 4.0, were a tad better at eking out some of the faint tail, than my first effort, the resultant images were riddled with unattractive artefacts from the pp effort of pushing the image data to reveal the fainter details of the comet. But, I will let you decide, whether or what you like, or otherwise, from the images below!

Image 1

Image 2

Image 3

Image 4

I suspect that this will be among the last of my imaging efforts of Comet Neowise, with the brightening moon promising to interfere with what little is visible of the comet as it is, while it is still predicted to remain in our view until the end of the month, after which the comet will disappear, on its travels to other parts of the solar system, for over 6000 years. 

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Comet Neowise from a Chennai terrace

Author: Ravi Kailas

The barely discernible Comet Neowise in the only image I managed to capture, before the clouds took over

An unusually (relatively speaking) clear July sky over Chennai (13N 80 E) yesterday evening (21/07/2020), prompted me to drag my behemoth 8" Dobsonian telescope onto the terrace, to enjoy the spectacles that the summer night sky, with the star rich regions of the Milky Way, its numerous star clusters, star clouds and Nebulae, (potentially!) visible in the early hours of the night. Saturn (just past opposition, incidentally) and Jupiter, also rise just after sunset and plonk (not exactly) themselves at a nice height to view, at an 'earthly' time of the night. While fiddling around with pointing the telescope at Saturn, with a temperamental base (that rotates smoothly for 358 degrees and tightens up for the other 2, invariably, just in the part of the sky that I want to look) and guide scope, I happened to turn around and look at the section of the barely exposed (from my terrace, given a tall building that blocks a chunk of the sky in this direction) northwest section of the sky, through my 10x42 binoculars, to find a faint, fuzzy bluish-green source of light. Suitably interested, I clicked a hasty picture with a 40-150 2.8 lens on an M43 camera, at 150mm (300mm full frame equivalent) for 5 seconds @f2.8, ISO 200 (I would have pushed this to 3200, if I had a bit of time to think) which showed up the faint vestiges of a tail (light pollution and high clouds in that section of the sky, the culprits, I suspect, apart from likely imperfect focus, given the hasty set-up), confirming that it was indeed a comet and my Star Walk 2 app, confirmed that it was Neowise. While it was a far cry from the brilliant pictures circulating online, and, I am given to believe, views through the binoculars, that this comet (a naked eye object, the likes of which was last seen when Comet Hale-Bopp graced our skies in the 90s) has delighted watchers of the northern skies with, over the last month or so,  it was nice to see  it all the same, in Chennai's almost perennially hazy skies (I did try earlier as well, in a brief window of somewhat clear sky, around sunset, a couple of days ago but no go). Hoping to get an opportunity at a better view though! The good news, that the Comet is projected to stay longer  above the horizon in the early part of the night, for the next few days at least. Just for reference, I saw the comet at around 19.40, a few degrees below and southwest of Ursa Major's pointer star, but as for all celestial objects, its position is dynamic and if you are seeking an audience with this tailed wonder, you would be well advised to look at its current position, rising/setting times, with a night-sky app. 

However the night was not just about the comet, and I had good views of the double double (Epsilon Lyrae - a star system that appears as a single star to the naked eye, but reveals itself, with the appropriate magnification/resolution, as a double star, and look closer, with a companion each - a great test for your optics and eyes!) in Lyra, Alpha (and one of its companion stars) and Beta Centauri, shining bright, low in the south, the crisply clear summer triangle formed by Vega, Deneb and Altair, the stunning contrast between a golden-yellow star and its bluish-white companion of Albireo, the vast Scorpius Constellation and its nuances, the dense collection of stars that make up Sagittarius Star Cloud, the intricate pattern formed by the bright stars of the Ptolemy Cluster, the tightly knit Butterfly Cluster, Jupiter and Saturn - all told, a satisfactory night of sky-gazing, by Chennai standards, which had both good seeing for the planets and transparency for the fainter objects, albeit marred by high clouds in some parts and fast moving, lower clouds, obscuring views on occasion. 

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