NGC 1554 / 1555 (Sh2-238) Bright Nebula in Taurus

Located at: RA 04 hours 21 minutes 57 seconds, Dec +19 degrees 32 minutes 00 seconds

Size: 1.5' Magnitude: -- Class: Reflection / Emission (Sharpless) 3 2 3

North is up

West to the right


 8" f5 Newtonian reflector


 ST-8XME, self-guided, binned 1x1, temp -25c, camera control MaxIm DL 4.56


Lumicon Red filter, 770 minutes (77 x 10 minute subs), 02/4/8/9/11/2012; seeing 2.8-4.0 FWHM per CCDStack


 CCDStack 2.60.4420.19802, Photoshop CS5.1


 Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s)


Finally gave up on this object ... not much went right during most of my imaging sessions in early February. Could not center the field the same as the 12/2006 image, so I ended up with a faint guide star that needed a 9-11 second exposure. The first two imaging nights had the moon very close to NGC 1554/55, causing reflections in the image. Then came bouts of clouds. And finally, I got my 'primary' drive corrector fixed, and started using it ... but have to get used to the unusual drive rates (slow=53Hz, fast=93Hz). Ended up taking 134 subs, of which this image represents the 'best' 77 subs ...

This image replaces a 220 minute red-filtered image from 12/22/2006.

See here for a link to  my 14.5" f5 Newtonian reflector hypered Kodak Tech Pan film image of this object. See the 14.5" ccd version.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 1554
NGC 1554 = Struve's Lost Nebula = LBN 817 = Ced 32a = Sh 2-238
04 21 43.5 +19 31 14

17.5": at the position of Struve's Lost Nebula is a mag 14 star noted in the 
observation of N1555 (Hind's Variable Nebula).  This star is 4' WSW of T Tauri 
and is not involved with nebulosity.

Struve's Lost Nebula is part of the T Tauri nebulosity with N1555 (Hind's 
Variable Nebula).  Discovered by O. Struve in 1868 and also observed by 
d'Arrest.  Described in the Notes section of NGC by Dreyer as "neb, S, with an 
eccentric nucleus = *14".  He notes that he was unable to perceive any 
nebulosity near the place with Lord Rosse's 6-foot telescope in 1877 and not 
found by Tempel.  In the IC 2 notes and corrections section, Dreyer comments 
that Struve's nebula was not found by Barnard in 1895 or by Keeler on plates 
taken in 1899.

Modern sources such as Sky Catalogue 2000.0 group N1554 and N1555 together as a 
single object, although Corwin notes that NGC 1554 is not visible on the Palomar 
Sky Survey plates.  At the NGC position and Bigourdan's position, there is a mag 
14 star.  RNGC incorrectly groups N1554/1555 together and places them about 1 
tmin too far E.  See NGCBUGS for more of the story.

- by Steve Gottlieb
Historical Research Notes / Correction for NGC 1554
NGC 1554 and NGC 1555 are both involved with the young variable star T Tauri.
They are among the most notorious of the nebulae found during the 19th century
as they are the only nebulae certainly known to vary in brightness -- even to
the point of disappearing, as NGC 1554 has done.  They are most likely 
reflection nebulae, created as thick dust clouds near the star move about, 
mostly casting shadows, but occasionally letting "shafts of sunlight" out to 
illuminate the surrounding dense interstellar gas and dust.

Nebulae were first noticed around the star by Hind in the 1850's, and were 
later observed by d'Arrest, Struve, and Dreyer among others.  Dreyer has brief
synopses of the observations in the NGC and IC Notes, and points (in the IC2
Notes) to a paper by Barnard in Monthly Notices which details most of the 
history of the T Tauri nebulae up to about 1900. 

For all the fuss that these nebulae created in the 19th century, they are all
quite small and very faint at the present time.  As I noted above, NGC 1554 is
not visible on the Palomar Sky Survey plates (taken in the early 1950's).  
Also not visible is a nebula seen only by Bigourdan (B. 144; mislabeled as B.
143 by him in his big table).  He makes it's position 04 19 09.5, +19 21 51 
(B1950.0) from a single observation on 12 Dec 1890.  This is about 4 arcmin 
south-east of T Tauri in a blank patch of sky.

Still, observers might find it fascinating to monitor the area for changes.
 - Dr. Harold G. Corwin, Jr.