Saturday, August 27, 2022

processed GRB 34

Assembled Groombridge 34 (GX Andromedae) in using the LRGB data files.

All this talk of late got me thinkin' that I need to see the colours...

The image run was on 28 Sep '17

double star system GRB 34 in colour

Gold orange stars, A and B. The bright star below is wildly different.

C is colourless.

Thursday, August 25, 2022

collected Helix RGB data

Back on 11 Aug '22, I programmed the BGO to get lots of data on the Helix planetary nebula (NGC 7293).

Received good luminance and narrowband on 20 Aug.

And finally the RGB data came in. Transparency was off so I'll try again.

All in an effort to improve on the what was collected back in 2018.

heard back from USNO

I heard back from the US Naval Observatory.

I had sent a message to Rachel Matson. She's in charge of the Washington Double Star database. I let her know of the recently discovered issue with Groombridge 34.

She pinged me ('round midnight, huh).

Thanks for the thorough investigation!  Indeed it does look like GRB 34A = GX And, while GRB 34B = GQ And.  The relevant files have been fixed and will be reflected online after the next WDS update.

Good stuff!

Monday, August 22, 2022

helped with LHS labelling

Melody asked me for some help with an image. 

It was the image I have used in my talks on measuring double stars, emphasising common proper motion (CPM).

example of common proper motion

The image by Ohkura shows a pair of stars moving to the left over the course of 50 years. They maintain the same position and angle to each other but move together against the background stars.

She specifically inquired about the labelling. "Do you know about the numbers directly under the photos? I get Andromeda [constellation] but what does LHS 3=GX and LHS 4=GQ mean?" She wanted to know in case someone asks during her upcoming Nova East talk.

I did a deep dive (as usual)...

"LHS 3 = GX And, LHS 4 = GQ And" means that one of the stars is known has LHS 3 or GX And. And the other star is known as LHS 4 or GQ And. The imager or researcher used the equality symbol (=) as the word "or" to mean "it's called this or that".

The comma (,) is a separator for a short list, indicate two items, the two stars. Although there's an issue with that (which I discuss later)... Again, the GX is one of the stars, the GQ is a different star.

Finally if it is not obvious "And" does not mean "and."

I had to look up the LHS acronym but I suspected (rightly) it was just another catalogue. From amazing wikipedia. "LHS" refers to the Luyten Half-Second Catalogue of stars with proper motions exceeding half a second of arc annually. See the star catalogue topic for more info.

This is a rather specialised catalogue so not commonly referred to except for fast-moving stars (e.g. Barnard's). In general, LHS designations are not used in SkyTools.

Stars with two letters and the constellation are usually variable stars. So one might have greater luck finding these stars by the two-letter designation in Stellarium or Sky Safari or SkyTools, etc. For example, if one looks up GX Andromedae, you'll land at the double (multi-) star system, well known as Groombridge 34 (GRB 34). And that's the primary [discoverer] in the WDS.

I examined Stelle Doppie.

GX refers to the A and C stars while GQ refers to A and B.

LHS 3
WDS ID: 00184+4401 GRB  34AC
GX And - variable star name
GRB 34 (Groombridge) - prime WDS discoverer
Coord 00 18 22.88 +44 01 22.6
https://www.stelledoppie.it/index2.php?iddoppia=1218
i.e. the A and C pairing
separation: 227.0" (super-wide)

LHS 4
WDS ID: 00184+4401 GRB  34AB (CQ And)
CQ And - variable star name ***
GRB 34 - prime WDS discoverer
Coord 00 18 22.88 +44 01 22.6
https://www.stelledoppie.it/index2.php?iddoppia=1217
i.e. the A and B pairing
separation: 34.5" (close)

[Note! Stelle Doppie shows CQ for the AB pair. This appears to be a typo! It should be GQ. CQ And refers to a different star, at RA 02 31 32, Dec +45 56 37, over near Almaak.]

Stelle Doppie, as good as it is, does not show ALL the other designations for the components of this double.

It's better to use SIMBAD...

For example...

https://simbad.cds.unistra.fr/simbad/sim-basic?Ident=gx+and&submit=SIMBAD+search

pulls up GX And

also known as

HIP 1475
HD 1326
GRB 34
SAO 36248

and

LHS 3

I shared one other thought. The C star is not shown in the proper motion images! I think it is such a wide pair that it is out of frame. So it is actually a misleading label! Ha!

§

Melody replied, "How can a person to know all this information?!" Heh. Guess I'm an astro-nerd...

We confirmed various details.

Melody posited, "The stars in the photo are variable red dwarf stars in a binary relationship."

I shared that I didn't know about that. Not sure the stellar class. 

Also: Binary? If one uses the word "binary" to casually to mean two stars, sure. But I use "binary" to mean "orbiting." These aren't orbiting (it seems).

She was happy to find the stars in SkySafari. She felt comfortable and familiar with how I presented the information on the labelling.

She thanked me profusely. "I’d never have figured this one out!"

§

I looked up the LHS numbers for the CPM stars I image with BGO every year.

Barnard's Star: LHS 57

Wolf 359: LHS 36.

§

I re-examined Stelle Doppie.

Actually the AB pair is a binary! But it has a 2600 year period. The "grade" (or certainty) of the orbital data is 5 (out of 9). 1 is definite and 9 is indeterminate. So this is in the middle. We need more data! ;-)

Stelle does say for AB the system is "physical." We know that from CPM studies...

The spectral class of AB is:
M1V + M3.5V (red/red)

So they are red stars!

Unfortunately, there's no spectrum for the C star.

I forgot I imaged this with the BGO!

And I visually observed a couple of years after that. 

Noted the colours.
A yellow-orange
B red
C blue or green

§

Processed GRB 34 in full colour on 27 Aug '22.

learned a word

I wondered this out loud recently, when discussing the Pleiades open cluster.

What does "subaru" mean?

I only learned this today.

To come together. To unite.

I also learned why the car logo has one big and five small stars...

Saturday, August 20, 2022

imaged neglected double STI 2505 (Halifax)

I asked the BGO Robotic Telescope to aim to a part of the sky in Cygnus to get data on a neglected double star.

According to the Washington Double Star database, STI 2505 has only been observed twice, first in 1903 and then in 1917. Data over 100 years old. The most recent position angle is 15; separation 10.2. Faint pair at mags 11.9 and 13.2. No spectroscopic values. 

I initially tried to use the Tycho designation 03940-0251 1 but it was not found in the BGO catalogues. Stelle Doppie did not have any other label except the Gaia. So I used the WDS code. No problemo.

The Burke-Gaffney Observatory returned the following.

region around STI 2505 in luminance

FITS Liberator, GIMP. North is up; east is left. Luminance, 1 second, stack of 12 exposures. Magnitude depth approximate 16.

There's the obvious wide pair near the centre of the image. The upper (north) star is the target, STI 2505. There should be a tighter, fainter star to the north-north-east. Nope...

The faint star to the NNE is J200903.8+554640, mag 14.3. It is actually along the same angle. So the B star of STI 2505 should be between. And B should be slightly brighter. Nope.

I checked the R, G, and B images. Nope.

Curiously, there's another double in the image, near the top-right. That's STI 2502! According to SkyTools 4, this is a pair of stars, mags 11.0 and 12.3, PA 71°, sep 15.1".

That's a good reference: STI 2505 should be similar. A bit tighter and more upright...

Conclusion: B star not visible. Missing. No obvious alternate candidates in the region. Is B a long-period variable star? Did the star quietly end? Did J. Stein goof up on the coordinates?

§

I wondered at all the streaks in the image. Satellites? But they show in the R, G, and B images in the same location. Sensor problems.

aurora tips

Was talking with Rhonda about aurora.

She was a little disappointed at not seeing anything lately, despite hoopla in the media, and legitimately strong indicators.

Frank clarified some things for me recently. You want a few factors aligned nicely to improve chances of seeing aurora in southern Ontario, assuming clear skies, obviously:

  1. kp-index 5 or higher
  2. Bz value negative 
  3. solar wind speeds >= 500 km/s 

I reminded her that the Sun is active now and is on the upswing. In fact, activity is trending above the expected levels. The next 5 years or so should be good.

received cool shirt

Received an early birthday gift!

Over one month early.

Rhonda gave me a neat shirt, like a Hawaiian shirt, but with an astro-theme!

Starry Night shirt for hot summer nights

Thanks!

helped with red film

Helped Don out.

He was looking for red film to cover screens.

Told him there was lots at the CAO.

imaged the Helix again (Halifax)

Wanted to have another go at the Helix Nebula aka NGC 7293.

Avoiding the Moon... (with a 5% maximum filter).

Both images: FITS Liberator, GIMP. North is up; east is left.

Helix planetary in luminance

Luminance only, 60 seconds subexposures, 10 stacked shots.

Helix planetary in hydrogen

H-alpha only, 60 seconds subexposures, 10 stacked shots.

In a separate imaging job, I've requested the RGB data for this Finest NGC object...

Much better results from before, from 1 Aug '18, thanks in part to longer exposures.

Friday, August 19, 2022

complained about forum

Sent a note to RASC national office relaying ongoing problems with the forum environment from Driven.

Newly added members are getting booted and then not receiving messages. We've no idea that they re not present. I myself cannot add them back in even though I'm supposed to be able to, as the moderator. And then we they can added back in, they still don't get messages until they manual subscribe?! Nuts.

Also, the message archives are messed up. Some extremely old messages are present but there's a bit gap, years of missing content. The forum is not a complete record of all our conversations. It is not working from an archival.

I complained to the executive directory and the president.

What a catastrophe.

Thursday, August 18, 2022

returned Dob

Returned the 10-inch Dobsonian. Chris V graciously helped. 

The unit from the David Dunlap Observatory that I repaired.

New Teflon sliders. 

Good to go. Although it needs collimation...

had a quick look

Peeked outside. From the darkened porch.

Clouds dissipating.

Didn't see anything. No glowing green skies to the north.

Wednesday, August 17, 2022

notified of kp-index 7!

Received alerts from the NOAA Space Weather service.

Noting kp-index 7! Haven't seen that for years...

Subject:  WARNING:  Geomagnetic K-index of 7 or greater (G3 or Greater)

Space Weather Message Code:  WARK07
Serial Number:  82
Issue Time:  2022 Aug 17 2035 UTC

WARNING:  Geomagnetic K-index of 7 or greater expected
Valid From:  2022 Aug 17 2031 UTC
Valid To:  2022 Aug 17 2359 UTC
Warning Condition:  Onset
NOAA Scale:  G3 or greater - Strong to Extreme

Potential Impacts:  Area of impact primarily poleward of 50 degrees Geomagnetic Latitude.
Induced Currents - Power system voltage irregularities possible, false alarms may be triggered on some protection devices.
Spacecraft - Systems may experience surface charging; increased drag on low Earth-orbit satellites and orientation problems may occur.
Navigation - Intermittent satellite navigation (GPS) problems, including loss-of-lock and increased range error may occur.
Radio - HF (high frequency) radio may be intermittent.
Aurora - Aurora may be seen as low as Pennsylvania to Iowa to Oregon.

Too bad it is cloudy here

Hopefully no power grids will get knocked out.

Tuesday, August 16, 2022

provided graphs

Melody reached out again. Ahead of her Nova East double stars talk, she's going to briefly discuss RASC observing programs...

She requested some graphs from the Observing Committee certificates database. Such as all certificates issued and those for her home centre.

I fired up Excel and readied to produce the needed charts.

It occurred to me to play with the colour palette. As we had discussed, dark backgrounds, astronomer-friendly.

RASC observing certificates to date

The certificates issued, to date.

watched Occult videos

Watched the recorded videos by David Herald on using the Occult software.

Over two sessions, about one hour each, he gave a fairly in-depth review of the asteroid occultation tool. First on setting up; second on recording and analysing.

These videos were captured as part of the Australian/New Zealand Trans-Tasman Symposium on Occultations (TTSO16) which was held in June and July 2022. I had registered for the events but could not attend live (primarily because of the 12 hour offset).

He's done amazing work. It really is amazing software.

I learned a few things.

And I got an idea, something I might try with Occult and OccultWatcher...

they reproduced it

Heard from the Stellarium crew at Github.

Hello @blakesphere! OK, developers can reproduce the issue. Thanks for the report! 

Hopefully 0.22.3 will have the fix for the Remote Control plugin...

Monday, August 15, 2022

imaged 70 Oph for 2022 (Halifax)

With the BGO, imaged the fast-moving double star 70 Ophiuchi aka Σ2272. 88-year orbit. 

A little late.

It's best around June but I forgot. Lots on my mind.

binary star 70 Oph in luminance

Special Observation method. North is up, east is left. LUM, 0.5 seconds, 12 exposures stacked. FITS Liberator and GIMP. 

Once again aimed at GSC 00434 02340. No Moon around. The pair to the bottom-right.  

Annual image log:

2016 Aug
2017 Jul
2018 May
2019 May
2020 May
2021 May
2022 Aug < you are here

Seven years, wow.

§

Funny. Melody and I were talking about this binary today...

shared SkyTools shortcuts

Read a thread on the Skyhound forums about how the Enter key no longer worked in SkyTools 4 for selecting or tagging items in an observing list.

A fellow user shared that one should use the "s" key instead. And pointed out it was not documented in the help system for the software.

I provided a link to my complete shortcut listing.

§

Back in February, in a different channel, I had noted this change in the application. Greg indicated he had to change it as he wanted the Enter key for something different when in Real Time Mode.

§

Member ledge1962 thanked me for sharing by listing for mouse and keyboard shortcuts. "Nice work." You're welcome.

§

Steve E from Lafayette sent a private email.

Your labor of love and geekdom is greatly appreciated.

Thanks for the tip of the beanie!

double classification

Helped Melody with the definition(s) of double stars.

We chatted by phone, to cover the ground quickly.

I sent a little infographic. She liked the visual.

She'll be at the Nova East star party in two weekends...

Saturday, August 13, 2022

testing Remote Control

Been playing a bit with the Remote Control plugin in Stellarium.

Chris asked me about it. I thought I had used it but I was thinking of StellariumScope...

It is a neat tool. Using a browser and a special GUI (through the Stellarium API) one can remotely control the Stellarium application. The effect in the program is compelling as the interface is not activated. In other words, Stellarium is easily controlled without distracting mouse pointer movement, toolbars flying up or right, and no on-screen windows or dialogues.

main screen of the Remote Control plugin

It offers some extra things such as a 30-degree field.

Chris is attracted to this to silently run Stellarium in his portable dome.

I believe it was invented for this: professional planetarium use. Show the sky and celestial objects without distractions in the app.

I reminded Chris V that the "chrome" in Stellarium can be toggled off with the Ctrl-t keyboard shortcut.

I could see it also being useful in demos, what's up in the sky talks, EPO events, etc.

But, very unfortunately, the search function (Selection tab) does not seem to be working for me. (Stellarium server 0.22.2, Chrome 103, Edge 104, LAN or local.)

Chris and I tested in older versions—works. So it is a new/recent bug.

I reported the issue (number 2568) in GitHub...

Friday, August 12, 2022

learned of mount woes

I've been following the activity at Killarney PP Observatory over the summer.

On reading Bruce's blog, I learned of trouble. The Meade 16 mount is acting up. Sounds serious.

Too bad. But it can still be used manually...  Ugh. That would be tough.

watched measuring video

Watched a video at Boyce Astro on using AstroImageJ to measure double stars.

Grady Boyce gave a relatively quick overview of how to measure PA and sep. for doubles with AIJ,

There is a supplement PDF file with goes into more detail.

A neat feature of AIJ is that it can also provide magnitude information.

Wednesday, August 10, 2022

processed The Whale

Processed the LRGB data for The Whale galaxy aka NGC 4631.

Used the data from 14 Dec '17.

Again, I used GraXpert on the original FITS files to flatten the gradients. Used the Kriging interpolation method this time, with manually placed sample points.

And, like before, this made the post-processing work easier.

The Whale galaxy in colour

GraXpert, FITS Liberator, Photoshop.

Tuesday, August 09, 2022

answered meteor questions

Received a public query to the RASC national Observing Chair address about the Perseid meteor shower.

I tried to reply as best as possible...

§

Meteor observing in general is easy to do.

From a comfortable reclining chair or from a picnic blanket on the ground, observe the whole sky. Some believe you should stare at the origin or source of the meteor shower but it is better to view at a 90 degree angle or more. So don't look directly at the constellation Perseus. Look west or south-east.

Meteor showers are often better after midnight so if you can stay up later, it's good to start viewing at 11:00 PM for a couple of hours or longer. 

Perseus rises in the north-east at midnight.

Unfortunately, the Moon phase is nearly full right now! It will be a full Moon on the 11th with the Perseid meteor shower peak on the 12th-13th. The bright Moon, and the brightened sky, will wash out many of the meteors. While the Perseids can produce over 100 meteors per hour, the fainter ones will be invisible. But hopefully some bright ones will punch through the bright sky.

If there is ANY cloud, the moonlight will illuminate the clouds and further reduce visibility.

I don't want to dash your hopes but this year is not ideal. But give it a try and plan for an even better showing in 2023.

Good luck!

§

They asked about "booking" the Morgan Arboretum. I wasn't sure where they were talking about. Perhaps the reserve in Sainte-Anne-de-Bellevue? I said I didn't know the procedures for the location. I didn't know if it was open to the public for evening use.

§

Visit the IMO or AMS for detailed information, such as peak times.

bon voyage Danuri

South Korea embarked, with the help of a Falcon 9 rocket, on a Moon mission last week.

The Korea Pathfinder Lunar Orbiter (KPLO) named Danuri will join spacecraft from NASA, India, and China. There's a lot of exploration happening of Earth’s neighbour.

It will take four months for Danuri to complete the journey using a ballistic lunar transfer trajectory. Tune in mid-December. The primary science mission should begin in February.

The Korea Aerospace Research Institute of South Korea has also signed up to join the NASA-led Artemis Accords.

received SN Sep-Oct

Received SkyNews comps for Sep/Oct.
 
SkyNews magazine cover with Milky Way core

Oooh. Cover alludes to an article on our galaxy's black holes...

Monday, August 08, 2022

processed again

Had another go with NGC 3628 aka the Hamburger.

Big difference this time is that I applied the gradient removal (splines) to the original FITS files. Then did the normal workflow. It was much easier. And made for a simpler Photoshop stack.

It was worked very well, I think.

Hamburger galaxy in colour - again

GraXpert, FITS Liberator, Photoshop.

Picked up a few suggestions and tips after watching the video by Frank on the GraXpert web site.

Sunday, August 07, 2022

processed the Hamburger

Process the Hamburger galaxy in colour.

Not easy.

Gradients in each channel. Tried a new tool to help. Not real happy with the final result.

Anyhoo, here it is.

NGC 3628 in colour

FITS Liberator, GraXpert, Photoshop.

Used the data from 22 Mar '20.

received aurora notifications

It worked. Received my first notification from the SWPC.

A few of days ago I was reading something and got the impression that alerts for potential aurora could be had for free from the NOAA Space Weather Prediction Center. Many a time I had visited and used the SPWC, in particular the Space Weather Enthusiasts Dashboard, but I had never decoded the notification system. 

I dug a bit deeper on the 4th, learned it was easy, free, created a profile, and registered for a few services.

In the wee hours, an email arrived with "warning" in the subject line. The first aurora notification. Which confirmed I had set things up correctly...

Subject:  WARNING: Geomagnetic K-index of 4 expected
Date:  7 Aug 2022 07:53:42 +0000
From:  SWPC Product Subscription Service 

Space Weather Message Code: WARK04
Serial Number: 4061
Issue Time: 2022 Aug 07 0752 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2022 Aug 07 0752 UTC
Valid To: 2022 Aug 07 1800 UTC
Warning Condition: Onset

Happy with this. Hopefully if something big is coming down the pipe, I'll be able to take advantage.

§

At 8:04 AM, I received an "alert" message.

Subject:  ALERT: Geomagnetic K-index of 4
Date:  7 Aug 2022 12:04:20 +0000
From:  SWPC Product Subscription Service

Space Weather Message Code: ALTK04
Serial Number: 2281
Issue Time: 2022 Aug 07 1203 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2022 Aug 07 1200 UTC
Synoptic Period: 1200-1500 UTC
  Active Warning: Yes

§

Oh ho. Another one. This time, indicating kp-index level 5!

Subject:  WARNING: Geomagnetic K-index of 5 (G1)
Date:  7 Aug 2022 14:30:24 +0000
From:  SWPC Product Subscription Service 

Space Weather Message Code: WARK05
Serial Number: 1654
Issue Time: 2022 Aug 07 1429 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2022 Aug 07 1428 UTC
Valid To: 2022 Aug 07 1800 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Once again, I'm rather pleased with how this all works. Thank you, NOAA and SPWC!

Friday, August 05, 2022

noted deleted request

1 Some time back, I loaded BGO with a request to image the supernova near M60.

2 2022hrs in NGC 4647. Aimed at star GSC0087800222.

Sadly, the queued job was not processed.

Today, the operator deleted the job. Out of season or "stale"...

Thursday, August 04, 2022

testing Our Galaxy

I've been playing around with the Our Galaxy application, app, tool, software thingee...

This is the current incarnation of Where Is M13?

The old astronomy software application (for computers only) was a neat tool that showed a top-down (plan) and side (elevation) view of our galaxy and where selected objects were. As you viewed the two panels, you gained a sense of where the object was in three dimensions. Was it above the plane of the galaxy or below? Was it ahead or behind (from a galactic coordination perspective)? Was it near or far?

I wrote a review of Where Is M13? back in 2016 for my Binary Universe column in the February RASC Journal.

Over the years, I used the tool often for educational purposes (see example 1 and example 2).

Some time ago, I noted some chatter on Cloudy Nights. The author had a new version available.

I downloaded it a couple of days ago. And it's great.

Some of the big improvements are that is offers a true three-dimensional interactive view that may be panned. This further heightens the feeling of flying around in space. Also, it now runs on mobile devices. I tested in on both the Windows 10 (64-bit) and Android. The interface is quite different so that's taking a little while to get used to. Oooh. Red light mode is now available!

I sent a bunch of questions and comments to the developer.

I think I'll do a full proper new review of Our Galaxy in JRASC as it is quite different...

Wednesday, August 03, 2022

returned to the Little Gem (Halifax)

Wanted to have another go at the Little Gem or NGC 6818.

I first imaged this small planetary nebula, during my RASC Finest NGC campaign, back on 12 Jul 2016. At the time, I made a note to get more LRGB data and narrowband.

On 4 Jul 2018, I received more data but the quality was very poor. I gathered data again on 7 Sep 2020 but did not make any remarks on the results.

So, one more time for fun...

Submitted requests to the Burke-Gaffney Observatory on 30 Jul 2022.

And waited for the BGO robot to return from vacation...

The full spectrum, i.e. luminance and colour data, was completed at 00:06:39 ADT.

Little Gem in luminance

Luminance only, 15 seconds subexposures, 20 stacked shots. FITS Liberator, GIMP. North is up; left is east.

Fifty minutes later, the narrowband data was captured.

Little Gem in h-alpha

Hydrogen-alpha, 60 seconds subexposures, 10 stacked shots. FITS Liberator, GIMP. North is up; left is east.

Little Gem in O-III

Ionised oxygen, 60 seconds subexposures, 10 stacked shots. FITS Liberator, GIMP. North is up; left is east.

Curious the image shift in the narrowband filters.

Bright in all channels...

OK. I think I have enough data now.

learned who made a song

Stumbled across a YouTube video on the early Pink Floyd days. In the 70s, I jumped on the bandwagon with the Dark Side of the Moon, after Syd Barrett had left.

While watching fascinating early performances and promotional pieces, I perked up for one particular song, Astronomy Domine. Wait. What?

I thought Voivod did that song! Many moons ago I bought the Canada metal band's 1989 Nothingface album primarily for this song. I just assumed they wrote it...

Wrong.

This was an eye-opener. Pink Floyd made this peculiar song.

Listen to the isolated song by Barrett et all.

Floating down, the sound resounds
Around the icy waters underground
Jupiter and Saturn, Oberon, Miranda and Titania
Neptune, Titan, Stars can frighten

It is widely regarded as their first astronomy-themed psychedelic masterpiece.

Monday, August 01, 2022

reviewed Rosette captures

Back in November and December last year, I spent some time imaging the Rosette Nebula.

Didn't feel like blogging about it at the time. Those were some dark and stressful days...

Anyway, the plan was to get lots of frames to make a mosaic. 

The Rosette Nebula, also known as NGC 2237, is a member of the RASC Finest NGC list. I had first imaged it in January 2021 with a single frame but that didn't do it justice. The one frame showed but a tiny fraction of the fine celestial object.

The Rosette is huge! Wikipedia says the apparent dimension is 1.3 degrees.

mosaic planning for the Rosette Nebula

I did some early planning and testing in October and came to the conclusion that I'd need a 4 by 5 set to encompass the entire nebula. 

Reported some strange offset issues to the human at the Burke-Gaffney Observatory and things settled down after that.

Captured data on the following evenings:

  • 6 Nov '21
  • 9 Nov '21
  • 10 Nov '21
  • 11 Nov '21
  • 12 Nov '21
  • 15 Nov '21
  • 17 Nov '21
  • 21 Nov '21
  • 21 Dec '21
  • 23 Dec '21
  • 26 Dec '21
  • 27 Dec '21
  • 4 Jan '22
  • 21 Jan '22

For each panel, I requested luminance data, hydrogen-alpha, and ionised oxygen (for each, 60 seconds, 10 subexposures). All centred on the star HIP 31130.

incomplete Rosette Nebula mosaic in luminance

Overall, things went well. Good coverage and fair overlap of the frames.

But the seasonal window closed and I had two panels to collect. So, at that time, I shelved it for the near year...

The hard part will be the processing. Not my strong suit.

§

Created a reminder to resume work in mid-October.