Andrew

The Eagle in Hydrogen Alpha

I have been processing more images from this last week. This one is another classic nebula, the Eagle. The nebula, also known as M16 or NGC 6611 can be found in thick regions of of our galactic core towards the constellation of Serpens.

The eponymous eagle can be seen near the center of the brightest region, a structure of darker material likely held together by the gravity of objects inside it. In this case those objects would be forming stars, or protostars, the result of the dust and gas being drawn together under the influence of gravity.

I have a full set of color filters, once I have had fun re-doing many of these classic nebulae in hydrogen alpha I will probably begin doing full color versions. Color takes a lot more exposure time and much more processing. There are techniques to add H-alpha data to an RGB image to get more definition in the nebula structure, something I have not done and should probably figure out.

Trifid in Hydrogen Alpha

Next up is the Trifid Nebula in Hydrogen Alpha. This bright nebula is less than two degrees above the Lagoon Nebula as seen in the post a few days ago. Indeed, the bright wisps along the bottom of this shot are the northern bits of the Lagoon.

The Trifid, also known as M20 or NGC6514, is another stellar nursery where star formation is occurring as we watch. The dense gas and dust is being carved into a cavity by the stallar winds of these hot young stars within the nebula creating the bright core cut with dark lanes of dust that we see in this image.

To truly capture this region I need to take at lest one more frame of the area and put together the several resulting frames as a mosaic to cover this large and beautiful nebulae complex.

Trifid in Hydrogen Alpha — The Trifid Nebula in Hydrogen Alpha

Sh2-54 in Hydrogen Alpha

Sharpless 2-54 is an often overlooked nebula complex just 2° north of the far more famous Eagle Nebula M16. It is actually part of the same nebula complex the stretches from M17 through M16 to Sh2-54 and beyond. The nebula is much fainter, with not much appreciable without a camera attached to the telescope, thus the complex is not as well known.

The star cluster NGC6604 is found within the nebula, a collection of young stars recently formed from these clouds of gas and dust. In the photo here the cluster is seen just down and right of image center.

Again this image is taken through a hydrogen alpha filter to best show the wisps of glowing gas among the stars.

The nebula complex Sharpless 2-54 in Serpens in Hydrogen Alpha

The Lagoon in Hydrogen-Alpha

With summer upon us the central core of the Milky Way galaxy dominates the late evening sky. This allows an astrophotographer a rich selection of targets well placed for shooting all night long.

Among these targets are the large emission nebulae… M17, M16, NGC4628, NGC6334, NGC6357, SH 2-54, and a long list of others. The brightest among these nebulae is M8, the Lagoon nebula, a rich and complex region of star formation, sweeps of gas, and dark globules.

With a new hydrogen-alpha filter added to the camera’s filter wheel it is time to re-image some of these old favorites. The filter is a narrow-band filter allowing through a slice of the spectrum only a few nano-meters wide. The filter pass-band is centered on 656nm deep in the red, the glow of neutral hydrogen gas, this allows sharp images of these glowing nebulae complexes.

M8, The Lagoon Nebula taken in H-alpha light at 656nm

Another Night, Another Supernova

Supernova 2020jfo in M61 is not the only supernova occurring at the moment. Actually there are over sixty supernova in progress at the moment that we know of. The modern transient search programs locate them by the dozens, and while the average large galaxy might have one supernova a century, there are an enormous number of galaxies we can observe while monitoring for those great explosions.

Currently the brightest supernova is 2020hvf at magnitude 12.4 hosted by galaxy NGC3643 in Leo. Unlike the pretty face-on spiral of M61, this small 14th magnitude galaxy is completely outshone by the supernova. Looking at the image one is struck by the realization that for a week or two that one star is outshining the combined light of the hundreds of billions of other stars that make up an entire galaxy.

NGC3643 with supernova SN2020hvf on the evening of Mar 15, 2020

M61 with a Supernova

M61 has been particularly bountiful when it comes to exploding stars. This should not be a huge surprise as M61 is also experiencing rapid star formation. With a lot of new stars around some of the largest stars will die early and die big.

Early this month the Zwicky Transient Facility noted a new supernova in M61, now cataloged as SN2020jfo. This explosion is now visible at 14.7 magnitude and can be seen by modest amateur telescope of at least 8-10 inches aperture.

Eight supernovae have now been observed in M61: SN 2020jfo, SN 2014dt, SN 2008in, SN 2006ov, SN 1999gn, SN 1964F, SN 1961I, and SN 1926A, an unusual number for any galaxy. In contrast our Milky Way galaxy last experienced a supernova in 1604.

Between shooting other targets I stopped by M61 last night to take a few exposures of the galaxy and see this supernova for myself.

NGC4303 - M61 with supernova SN2020jfo on the evening of Mar 14, 2020 — NGC4303 – M61 with supernova SN2020jfo on the evening of Mar 14, 2020

ʻŌhiʻa Forest

While the beaches may be closed during the pandemic, most of the trails are open. Deb and I did a little walking on the Puʻu Oʻo Trail while coming back over the hill from Hilo.

Nothing unusual to report, no rare native birds. As the ʻōhiʻa are not in bloom few birds were in evidence. Even without blooms or birds this is always a pretty trail, a rugged landscape over recent lava flows and the pioneer plants found on these flows.

WP Photo Sphere (Ohia Forest)

Author: Andrew