Astro Anarchy

Tuesday, March 17, 2020

A rare image, Sharpless 205 and NGC 1491 in constellation Perseus

The imaging season is getting shorter up here 65N, in a few weeks we run out of an astronomical darkness for about six months.

Sharpless lays high at South East at around nine o'clock I can shoot it about five to six hours before my view gets blocked by a punch of antennas and the wall. I have about six degree field of view in my current imaging system, the Sh2-205 and NGC 1491 next to it fits very well in my field.

This is a very dim target, undersampled optical configuration, binning and a longish integration time helps to bring out details and faint surrounding nebulosity. I haven't seen many photos about this target around. Total exposure time 18 hours. (Note! 15 hours of it was shot binned down 2x2, that gives equal signal as 60 hours of 1x1 binned exposures!)

Sharpless 205 & NGC 1491

Click for a large image (~1300 x 1300 pixels)

Mapped colors from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.

H-alpha channel alone, labeled

Click for a large image

Image in light emitted by an ionized hydrogen (H-alpha emission line)

A 1:1 closeup

Full resolution detalji, NGC 1491 at middle up

An older long focal length image of NGC 1491

Click for a large image

Image from Spring 2015, more info here, https://astroanarchy.blogspot.com/2015/04/ngc-1491.html

NGC 1491 is a very dim target in Perseus. Original image from the Spring season 2015. Image is reprocessed, about twenty hours of new data added from the new wide field image. (Unpublished) Added data is very dim background glow from ionized hydrogen, sulfur and oxygen, it's pretty featureless so difference in resolution does no harm the image. The final photo is now deeper with better colors.

INFO

Sharpless 205 (Sh2-205) is a very dim emission nebula in constellation Perseus. The brighter peanut shaped area at the middle is known as Sharpless 205.

NGC 1491 is a little brighter emission nebula that lays at upper right corner of the image. It has a distance of about 11.000 light years from Earth. A strong stellar wind from a star BD +50 ° 886 is blowing the gas away. The radiation from the star makes the gas glow by ionizing elements in the nebula.

Technical details

Processing workflow

Image acquisition, MaxiDL v5.07.

Stacked and calibrated in CCDStack2.

Deconvolution with a CCDStack2 Positive Constraint, 33 iterations, added at 50% weight

Color combine in PS CS3

Levels and curves in PS CS3.

Imaging optics

Tokina AT-x f2.8 camera lens

Mount

10-micron 1000

Cameras and filters

Imaging camera Apogee Alta U16 and Apogee seven slot filter wheel

Guider camera, Lodestar x 2 and an old spotting scope of Meade LX200

Astrodon filters,

5nm H-alpha 3nm S-II and 3nm O-III

Total exposure time 18 hours
(15 hours was shot binned down 2x2, that gives equal signal as 60 hours of 1x1 binned exposures!)

H-alpha, 15 x 1200 s, binned 1x1 = 5 h
H-alpha, 21 x 1200 s, binned 2x2 = 7 h
O-III, 9 x 1200 s, binned 2x2 = 3 h
S-II, 9 x 1200 s. binned 2x2 = 3 h

Saturday, March 14, 2020

From Bubble to Cave, round II

I have published a horizontal version of this image few days ago, it can be seen here, https://astroanarchy.blogspot.com/2020/03/from-bubble-to-cave-nebula-area.html
This vertical version works too, it's little longer, than horizontal one. This area is part of much larger mosaic image of Cepheus, it can be seen here, https://astroanarchy.blogspot.com/2020/03/great-mosaic-of-cepheus.html

From Bubble to Cave Nebula

Click for a large image,

Image is in mapped colors from a light from the ionized elements, hydrogen = green, sulfur = red and oxygen = blue.

Sharpless 157, a Zoom Out Series
Click for a large image, NOTE, 4500 x 1024 pixels!

I made a Zoom out serie about Sharpless 157. It's a complex region near the famous Bubble nebula and it's kind of large. There are not too many photos of it around. I have marked the apparent size of the full Moon in each image. The angular size of a Moon is about 0,5 degrees, that's 30 arc minutes.
This kind of image gives an idea, how complex and fractal the gas structures can be. there are endless amount of variations and new details at every zoom level and beyond.

Technical details

The vertical image is taken with Tokina AT-x camera optics, Apogee Alta U16 astrocamera and Astrodon narrowband filter set. Info about my imaging system can be seen here,

https://astroanarchy.blogspot.com/2020/01/the-frankenstein-monster-my-current.html
Some older parts of the photo are taken back in 2014 with QHY9 astrocam, Baader narrowband filters and Canon EF 200mm f1.8 camera lens.

Photo is taken from downtown Oulu, Finland. Due to an extensive light pollution I can do only narrowband imaging in my location.

Total exposure time is around 20 hours.

Wednesday, March 11, 2020

From the Bubble to Cave nebula area

Yesterday I published a panoramic photo of constellation Cepheus, there is new material in upper left corner area of the panorama. I made an individual composition out of this interesting area, dark clouds of gas and dust are shadowing light from energetic emission areas. Bubble Nebula can be seen as tiny pearl like formation at middle left. Near the Bubble lays much large Sharpless 157, thae bright area at lower left. Cave Nebula is located to upper right area of the photo.

From Bubble to Cave

Click for a large image

Image is in mapped colors from a light from the ionized elements, hydrogen = green, sulfur = red and oxygen = blue.

Orientation

The area of the new image above is marked as a white rectangle.
Large image and information about this Great Mosaic of Cepheus can be seen here,https://astroanarchy.blogspot.com/2020/03/great-mosaic-of-cepheus.html

Technical details

Image is taken with Tokina AT-x camera optics, Apogee Alta U16 astrocamera and Astrodon narrowband filter set. Info about my imaging system can be seen here,

Photo is taken from downtown Oulu, Finland. Due to an extensive light pollution I can do only narrowband imaging in my location.

Total exposure time is around 20 hours.

Tuesday, March 10, 2020

Great Mosaic of Cepheus

At 2014 I published a large mosaic image out of Constellation Cepheus. I have now shot new photos from the area and I was able to update my original panoramic photo mosaic.
This is the second updated mosaic image in a week, first one was the Grande Mosaic of Auriga, it can be seen here, https://astroanarchy.blogspot.com/2020/03/the-grande-mosaic-of-auriga.html

I have now somehow better tools but also my skills has been improved. I have also reprocessed the original photo for better colors and details.

Original mosaic had 10 panels, since my current imaging system has much large image sensor, I was able to cover several panels with just two photos. The mosaic photo has resolution of 13.000 x 7000 pixels and it has twelve panels.
Originally I used The Canon EF 200mm f1.8 camera lens and QHY9 astronomical camera with Baader narrowband filter set. new material is shot with Tokina AT-x 300mm f2.8 camera lens and Apogee Alta U16 astronomical camera with Astrodon 50mm square narrowband filter set.
The total exposure time before current additions was around 92h. With new photos, the exposure time is now over 160h. (Most time is spend for the planetary nebula OU4 at upper right corner. 48 hours.)

Panoramic Photo of Cepheus

Click for a large image, it's worth it! (2400 x 1300 pixels)

Mapped colors from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
Large image 2400 pixels wide and ~4MB. Original resolution was about 13000 x 7000 pixels.

A detalji from a full size image
Click to see a large image