NGC2264 Christmas Tree Cluster & Cone Nebula

NGC2264 Christmas Tree Cluster & Cone Nebula; multi-session image comprised of data captured 29Dec2021, 9Jan2022, 17&29Dec2023 from HCH, Colorado Springs, CO and 28Jan2022 from Kiowa National Grasslands, NM

Fun facts

NGC 2264 is the New General Catalogue designation number identifying two astronomical objects as a single object: the Cone Nebula and the Christmas Tree Cluster.  Two other objects are also within this designation but not officially included, the Snowflake Cluster and the Fox Fur Nebula.  All the objects are located in the Monoceros constellation about 720 parsecs or 2,300 light-years from Earth.  

The Snowflake Cluster was granted its name due to its pinwheel-like shape and its assortment of bright colors. The Christmas Tree star formation consists of young stars obscured by heavy layers of dust clouds. These dust clouds, along with hydrogen and helium are producing luminous new stars. The combination of dense clouds and an array of colors creates a color map filled with varying wavelengths. Photographs taken by the Spitzer Space telescope differentiate between young red stars and older blue stars. With varying youthful stars comes vast changes to the overall structure of the clusters and nebula. For a cluster to be considered a Snowflake, it must remain in the original location the star was formed.

You may have read of NASA releasing Christmas holiday-related images by the James Webb Space Telescope, including the Christmas Tree Galaxy Cluster. This is NOT the same object! The JWST galaxy cluster is 4.3 billion light years from earth… (the story and image is here:

Distance: 2350 ± 52 light years
Apparent dimensions: 20’
Apparent magnitude: 3.9
Constellation: Monoceros
Designations: NGC2264, Cr112


Capture & Processing Notes

Multi-session Notes: December has been a month of experimentation with new equipment and new software. Starting the month with the addition of the ZWO EAF autofocuser and ending the month with the Rainbow Astro RC-300 mount, then upgrading SGPro and PHD2 just to throw a few more variables into the equation! The final imaging session of the year – 29Dec2023, capturing NGC2264 Cone Nebula was probably the most successful (although there were a couple of hours lost when the autoguider camera failed). The result was good but a little monotonic because of the LeXtreme filter against the 90.8% waning Gibbous moon. So, I decided to make a multi-session image with (almost – APP will only handle 5 sessions) the data I’ve captured on this object over the last two years (to the day!).

Capture Notes (29Dec2021 & 9Jan2022): I wasn’t keeping a detailed journal during 2021 and wasn’t fully up to speed with my journaling process until later in January 2022, so I just have the images, session details from the RAW data, but no other notable information for the notes. But, by all accounts (the number of images captured) these data captured with the Canon EOS Ra and Big Bertha before I had any light pollution filters were pretty darn good!

Capture Notes (28Jan2022): These are the only dark skies data in the image. I imaged NGC2264 during both 28Jan2022 and 29Jan2022 during our dark skies trip to Mills Canyon in the Kiowa National Grasslands. Both nights, NGC2264 was the second and final target of the night during cold conditions (16deg Friday, 22 degrees Saturday) and with a setting target. The mount parked the telescope in RA but froze in Dec by the end of each session. Friday night the battery power (of the Beast) was so drained, I couldn’t even power the laptop to capture calibration frames! The original sequence plan to be executed both nights was ISO1600; 50x300sec. On the first night (28Jan2022), I captured 40x300sec. Of those subframes, I captured good frames: 29Jan22, 0034 – 0236 rejecting seventeen (17) frames captured at 0134 and between 0236-0400. On the second night (29Jan2022), I captured 21x300sec, with 15 rejects due to star trailing. Only the data captured on Friday, 28Jan2022 are included in this image.

Capture Notes (17Dec2023): This session was “first light” with the new Rainbow Astro RST-300 mount. I had quite a few start-up issues (the most substantial (and frightening) being the mount thinking it was still in Korea even though I had entered the location, date-time, etc. into the handset prior to starting the session). I had also upgraded my control software to SGPro v4.3.0.1265 and was continuing to have issues with its plate solving directing a change in the camera angle at the meridian flip. It was not as severe during this image capture as it was with IC443 Jellyfish, but still bad enough that I could only include the post-flip subframes in this image. The directed camera angle change of 30 degrees required new flats, thus a “session” of their own in the APP stack (which only allows 5 sessions to be compiled into an image).

Capture Notes (29Dec2023): Ironically two years to the date that I started imaging this target! After spending an inordinate amount of time in December 2023 on IC443 Jellyfish Nebula, I decided to spend the last clear night of 2023 on NGC2264 Cone Nebula. This image was captured with all the “changes” that I’ve made over the last six weeks in place – new mount (RST-300), new autofocuser (ZWO EAF), new software (update to SGPro from v3.2.0.660 to v4.3.0.1265). Yes, violating the scientific method by changing way too many variables at one time!! But, during this session, they all came together just fine. The issue I had during this session was with the autoguider. The guide camera lost connection to the laptop and terminated the sequence (even though I had finally figured out and implemented SGPro’s recovery mode) just before the meridian flip and for a two hour period between 0200-0400MST. Despite that data loss, I still captured 81 subframes. I attribute the electrical disconnect to the way the cable connects to the end of the autoguider camera – it’s precarious. After the 0400 restart, I draped the cable on the EAF’s bracket, which seems to work well.

Sequence Plans

This image is comprised of data collected during five imaging sessions, over a two year period – 29 December 2021 through 29 December 2023. All but one of the sessions was executed from the front patio of our home in Colorado Springs. The data collected on 28 January 2022 was collected from the dark skies of Kiowa National Grasslands, New Mexico. Total imaging time was 24:03 hours.

  • Sequence plan (29Dec2021): ISO1600; 96x3min; captured 29Dec2021, 1918MST – 30Dec2021, 0103MST.  Total exposure time: 4:48hrs.
  • Sequence plan (9Jan2022): ISO1600; 150x3min; captured 9Jan2022, 1912MST – 0322MST.  Total exposure time: 7:30hrs.
  • Sequence plan (28Jan2022): ISO1600; 22x5min; captured 29Jan2022, 0034MST – 0236MST.  Total exposure time: 1:50hrs.  Captured at Mills Canyon K90A, Kiowa National Grasslands, NM
  • Sequence plan (17Dec2023): Gain 158, Offset 30, Temp 0°C; 49x5min. Captured 17Dec2023, 2212MST – 18Dec2023, 0628MST.  Total exposure time: 4:05hrs.  Collection had 30° degree shift in framing at meridian flip (90° to 120°), so this image only contains the post-flip subframes due to APP limitation on 5 sessions (needed separate flat frames).  In this image: Gain 158, Offset 30, Temp 0°C; 38x5min. Captured 18Dec2023, 0234MST – 18Dec2023, 0628MST.  Total exposure time: 3:10hrs. 
  • Sequence plan (29Dec2023): Gain 158, Offset 30, Temp 0°C; 81x5min. Captured 29Dec2023, 1953MST – 30Dec2023, 0515MST.  Total exposure time: 6:45hrs.
  • Total data included in image: 246x3min + 141x5min = 1443min (24:03hours)


Data captured with SGPro. Images culled by viewing with FITS Liberator. Star removal with StarNet++ v2. Processed with Lightroom and Photoshop.


All equipment controlled by HP Probook running Sequence Generator Pro

  • Imaging:
    • Ra-BB (29Dec2021, 9 & 28Jan2022): Canon EOS Ra; Orion 8″ f/8 Ritchey-Chretien Astrograph Telescope
    • ASI2400-BB-FF-LeX-EAF (17 & 29Dec2023): ZWO ASI2400MC imaging camera with Teleskop Service Flattener 1.0x for RC Telescopes (TS-RCFLAT2) and Optolong L-Extreme LP filter; Orion 8″ f/8 Ritchey-Chretien Astrograph Telescope. 
  • Autofocuser:  ZWO EAF Electronic Automatic Focuser – Standard (EAF-5V-STD)
  • Mount:
    • BB – EQ6R (29Dec2021, 9 & 28Jan2022): Sky-Watcher EQ6-R Pro Equatorial Mount (controlled by EQMOD)
    • BB – RST-300 (17 & 29 Dec2023): Rainbow Astro RST-300 (controlled by iHubo)
  • Polar alignment: QHYCCD camera (controlled by Polemaster for polar alignment)
  • Autoguiding:  Orion 60mm Multi-Use Guide Scope with Orion StarShoot AutoGuider Pro Mono Astrophotography Camera (controlled by PHD2);