Celestial hemisphere:  Northern  ·  Constellation: Taurus (Tau)  ·  Contains:  Hind's variable nebula  ·  NGC 1554  ·  NGC 1555  ·  Sh2-238  ·  Struve's Lost nebula  ·  VdB28
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NGC 1555 - vdb28 - Hind's Variable Nebula, 



    
        

            Gary Imm
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NGC 1555 - vdb28 - Hind's Variable Nebula

Getting plate-solving status, please wait...
NGC 1555 - vdb28 - Hind's Variable Nebula, 



    
        

            Gary Imm
Powered byPixInsight

NGC 1555 - vdb28 - Hind's Variable Nebula

Acquisition details

Dates:
Nov. 14, 2018 ·  Nov. 16, 2018 ·  Dec. 9, 2018
Frames:
Astrodon Gen2 I-Series Tru-Balance Blue: 120×30(1h) (gain: 139.00) -20°C bin 1×1
Astrodon Gen2 I-Series Tru-Balance Green: 120×30(1h) (gain: 139.00) -20°C bin 1×1
Astrodon Gen2 I-Series Tru-Balance Lum: 180×30(1h 30′) (gain: 139.00) -20°C bin 1×1
Astrodon Gen2 I-Series Tru-Balance Red: 120×30(1h) (gain: 139.00) -20°C bin 1×1
Astrodon H-alpha 5nm: 30×300(2h 30′) (gain: 300.00) -20°C bin 1×1
Integration:
7h
Avg. Moon age:
5.54 days
Avg. Moon phase:
34.21%

RA center: 04h21m48s.312

DEC center: +19°2218.74

Pixel scale: 0.782 arcsec/pixel

Orientation: -88.044 degrees

Field radius: 0.474 degrees

More info:Open 

Resolution: 3536x2582

File size: 7.4 MB

Locations: Backyard (Mag 20.8 - Bortle 4.5), Onalaska, Texas, United States

Data source: Backyard

Description

This image includes a series of objects located 400 light years away in a large molecular cloud in the constellation of Taurus. As usual, I have included this description of what I have learned by researching and observing this object. But a word of warning - of any object I have researched, I have found more inconsistent information related to this object than any other. I have tried to verify my description as much as possible, but there still may be errors due to these inconsistencies. I have also included an annotated image above to help explain the description.

The bright yellow-orange star in the center is T Tauri. This star is the prototype for the class of variable stars called T Tauri stars. These stars are young (less than about ten million years old) pre-main-sequence stars found near molecular clouds. T Tauri is responsible for HH255, a Herbig-Haro object (nebulosity associated with gas jets from newborn stars). This object can be seen in my image if you zoom in - it looks like two horns extending from the star. This object is also called Burnham's nebula, since it was one of the objects observed by Burnham at the end of the 19th century. This nebula is sometimes confused with the more popular Burnham's Nebula, which is NGC 7026.

Immediately above T Tauri is NGC 1555, known as Hind's Variable Nebula since it was discovered in 1852 by John Russell Hind. This reflection nebula is illuminated by T Tauri and is also known as vdB 28. Both the star (T Tauri) and this nebula are seen to vary significantly in brightness over time, but not necessarily consistent with each other. This may be due to another possible HH object, given the name HH155, which is believed to be embedded in this nebula. This nebula is included in the Sharpless catalog of HII regions as object Sh2-238, which is interesting since this nebula is a reflection nebula and not an emission nebula.

Numerous other very faint HH objects have also been identified in this region, all named with the prefix of HH355. Some of these are labelled on the annotated image. I believe that these HH355 objects are associated with T Tauri based on the symmetry of HH335B and HH3335D, located equidistant on each side of T Tauri. However, I could not find any documentation of this.

Also labeled on the annotated image is NGC 1554, nicknamed Struve's Lost Nebula. Nothing unusual has been seen in this location in modern times. It is debated whether this NGC entry is simply an observation mistake, or perhaps if a variable nebula flared up at this location in the 1860's and has not been seen since. I prefer to think the latter, and will continue to look for it in future years.

Comments

Revisions

  • Final
    NGC 1555 - vdb28 - Hind's Variable Nebula, 



    
        

            Gary Imm
    Original
  • NGC 1555 - vdb28 - Hind's Variable Nebula, 



    
        

            Gary Imm
    C

C

Description: Annotated for Herbig-Haro Objects

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NGC 1555 - vdb28 - Hind's Variable Nebula, 



    
        

            Gary Imm