Dark Nebulae LDN 1608 & 1609
Beverly T. Lynds Catalogue of Dark Nebulae (LDN)
Using photographs from the National Geographic-Palomar Observatory Sky Atlas in both red and blue, Lynds identified 1802 dark nebulae in the declination range +90° to -33°. This photograph by my Celestron Origin was centred on the star HD 260530 in the constellation Monoceros. Two dark nebulae and an open cluster are in the field of view: LDN 1608, LDN 1609 and NGC 2259.
Lynds used the 48-inch Schmidt at Palomar to find dark nebulae. She rated their opacity on a scale of 1 to 6, with 6 being the darkest. Both LDN 1608 and 1609 were given a rating of 5 on this scale. Distances to the nebulae were not studied in Reference 1. A list of measured distances to many of Lynds's dark clouds was assembled by Hilton and Lahulla (Ref. 2) in 1995, however, LDN 1608 and 1609 were not on the list. The authors hoped that additional distances would be measured in future so the list could be expanded. It does not appear that the distance list was revisited and updated with new measurements.
References
- "Catalogue of dark nebulae," Beverly T. Lynds, Astrophysical Journal Supplement, 7, 1-52 (1962).
- "Distance measurements of Lynds galactic dark nebulae," J. Hilton and J.F. Lahulla, Astronomy & Astrophysics Supplement Series 113, 325-331 (1995).
Logbook
- Date & Time: February 3, 2026, 9:34 pm
- Location: Kempt Shore, Nova Scotia, Canada, 45°N
- Conditions: Clear, light breeze, -5°C
- Moon phase: Waning crescent (13%)
- Sunset: 5:42 pm
- Technical: 10-sec exposures, 50-min integration, battery power, no filter, post-processing using Samsung Galaxy S23 Ultra built-in photo editing tools
Stellar Distances
Let's do a little research on this field of view and assemble a list of the stars with known distances. We start by using data in SIMBAD, the Stellarium Mobile Plus and SkySafari 7 Pro apps, and Ref. 3. All of these distances will have to be verified with original sources.
- GAIA DR2 3327772104399910656, V 12.81, d 1017.85 ly
- HD 46735, V 8.31, d 1212.50 ly, K2 (Star)
- HD 46883 (Karlsson-121), V 7.88, d 1800 ly, B3II (Star)
- HD 47156, V 6.50, d 497.19 ly, K0 (High proper motion star)
- HD 47271, V 8.88, d 248.91 ly, G0 (High proper motion star)
- HD 47337 (Karlsson-240), V 9.06, d 1306.56 ly, A0V (Star)
- HD 47397 (Karlsson-314), V 9.19, d 774.72 ly, A1IV (Emission-line star)
- HD 259856 (Karlsson-23), V 10.00, d 54.5 ly, A0/1 (Star)
- HD 259917, V 9.50, d 886.60 ly, G0 (Star)*
- HD 260016, V 9.88, d 1800 ly, A5V (Star)
- HD 260145 (Karlsson-61), V 10.44, d 1325.16 ly, A2/3 (Star)
- HD 260180, V 10.81, d ?, A5/7 (Star)
- HD 260281 (Karlsson-120), V 10.19, d ?, B3/5 (Star)
- HD 260382, V 10.06, d ?, K5 (Star)
- HD 260413 (Karlsson-119), V 10.81, d 948.25 ly, F0/2 (Star)
- HD 260477, V 9.88, d ?, K2 (Star)
- HD 260503, V 9.56, d 918.74 ly, F0/2 (Star)
- HD 260530, V 9.75, d 877.49 ly, K0 (Star)
- HD 260594 (Karlsson-181), V 9.56, d 139 ly, B6/9 (Star)
- HD 260664 (Karlsson-185), V 10.44, d ?, B6/9 (Star)
- HD 260665 (Karlsson-188), V 9.75, d 1003.54 ly, A5/7 (Star)
- HD 260792, V 9.31, d 470 ly, K0 (Star)
- HD 260932 (Karlsson-186), V 10.75, d ?, A2/3 (Star)
- HD 261051 (Karlsson-238), V 11.13, d ?, A0/1 (Star)
- HD 261052 (Karlsson-242), V 10.94, d ?, F0/2 (Star)
- HD 261200, V 10.75, d 771.01 ly, F5/7 (Star)
- HD 261229 (Karlsson-312), V 10.50, d ?, B3/5 (Star)
- TYC 0737-0282-1, V 11.25, d 674.03 ly, (Star)
- TYC 0737-0527-1, 10.75, d 919.17 ly, G (Star)
- TYC 0737-0533-1, V 10.88, d 1150.79 ly, (Star)
- TYC 0737-0791-1, V 10.56, d 484.13 ly, (Star)
- TYC 0737-0898-1, V 10.50, d ?, OB+ (Be star candidate)
* SkySafari says 86.3 ly vs Stellarium 886.60 ly
References
3. "The distribution of stars and obscuring matter in a Monoceros field," B. Karlsson, Astron. Astrophys. Suppl. 7, 35-81 (1972).