The Cat’s Paw or Bear Claw nebula (NGC 6334, Gum 64 and other designations), near the “stinger” of Scorpius.
A 9 minute Seestar S50 image, taken from suburban Adelaide on June 24 at around 1:30am.
This relatively bright emission nebula is slightly larger in angular size in the night sky than the full Moon, and was discovered by John Herschel in 1837.
Also, a picture of an actual cat (called Cowie) with real paws is included for reference. 🙂
An optical transient, initially designated PNV J19450648+1822422, was found in Sagitta with the NMW-TexasTech survey on August 25 as detailed in the Central Bureau for Astronomical Telegrams. Once confirmed as a nova, the designation was changed to N Sge 2026. It’s also known as V0488 Sge since it is (amazingly) the 488th variable in Sagitta.
Sagitta (Sge), the arrow, propelled by the bow of Sagittarius the archer, is a small constellation in the northern sky below Aquila, as shown in the wide-field Stellarium screenshot above. The approximate location of the nova is also shown.
The first image above results from stacking a hundred or so images, with noise removal, taken on August 27 starting at about 10:05pm with my Seestar S50. The nova is at centre and before discovery would not have been visible in this field.
The second image is a screenshot of photometry (using Tycho Tracker) carried out with a median stack of 42 of the best individual images. The small green squares in the lower left and right quadrants mark the location of the comparison stars I used for the photometry, and these stars are also visible in the first image.
The nova has so far reached a maximum visual magnitude of 6.9, up from its precursor magnitude of 21.3. At the time of writing, this is a plot of most visual observations submitted to AAVSO since discovery, with mine under the crosshairs. It is currently in decline but could very well become brighter again, and as always, we’ll see.
Sagitta fills the field of view of my 8×42 binoculars, and although I observed the location of the nova while imaging it with the Seestar, the nova and comparison star magnitudes, combined with a more than 99% illuminated Moon (effectively full) to the upper right of the field, made a visual estimate very difficult. As Luna rises later over the next few days, visual observation will be easier, but the nova may also be dimmer. The Seestar’s small field of view and sensitive imager provides an effective approach under these conditions.
An AAVSO finder chart suitable for attempting a binocular or telescopic visual observation is shown below, at least until it falls below magnitude 9.
In 2020 when other bird flu strains (H7N7, H5N2) led to the killing of hundreds of thousands of chickens and several thousand turkeys and emus on Australian farms, I wrote that:
If these events continue or even increase in frequency, I can’t help but wonder whether there will be calls to dismantle free range, in favour of barn laid or worse, a regress to caged systems; neither, a good outcome for the animals, but I can imagine it being “declared” necessary by authorities.
As I write this, there are 220 confirmed H5N1 bird flu cases in Australia, the last continent to be affected. Most of those cases are in South Australia. To reduce the risk of spread to free range chickens, an ABC News article on Aug 4 reports that the consumer watchdog (ACCC):
…has extended its pause on free-range egg labelling enforcement as some farmers move hens indoors to protect them from H5 bird flu on state government advice.
It goes on to quote the ACCC (Australian Competition and Consumer Commission) as saying that:
If they’ve got their birds housed, there’s an obligation to communicate that, particularly to retailers, but also more widely, to the consumers.
In the same article, the owner of a pasture-raised egg farm in Victoria is quoted as saying that:
I definitely don’t like the idea that someone can be marketing their eggs as free range when they’re not actually living like that.
He wants to see temporary label changes, allowing farmers to use the same cartons.
There’s a two-to-three-month wait to get a carton in … and when we do a minimum order, it’s 60,000 cartons.
It really wouldn’t be hard to have a sticker or something that we applied to our carton saying, ‘Temporarily inside due to government order’ or ‘during this outbreak.
I don’t think they should be able to continue just pumping out cartons of eggs, calling them free range when the birds are locked in for two or three months at a time.
The article ends with this:
SA’s chief vet, Dr Skye Fruean, said it was a “very dynamic situation and we are remaining really closely engaged with our poultry sector.”
She said a mandatory housing order was not in place yet, but was being considered.
Of course we want to reduce the likelihood of spread of diseases like H5N1.
The longer term worry however, is that this could be a slippery slope to a situation in which all chickens are kept inside due to potential pandemic risk. In the case of egg-laying hens, that may mean further delays to ending the caged egg system.
There is of course another approach that avoids the whole problem, but that’s not part of the public conversation.
It has been two and a half months since I first wrote about Nova Musca 2026 (V0419 Musca).
The light curve is somewhat more well developed. Visual band data are shown here.
The nine SeeStar S50 observations I made are shown in purple. Tycho Tracker was used for photometry.
Although the downward trend is clear, there’s a fair amount of up and down.
The astronomer’s telegram reported the discovery of a nova, V0419 Mus, in the constellation Musca on May 24 by K. Stanek of the All-Sky Automated Survey for Supernovae (ASAS-SN). Archival data showed the outburst started on May 10. AAVSO sent out an alert notice on May 29.
Last night was the first opportunity I’d had to attempt an observation. Although the sky conditions were far from ideal, between clouds I obtained enough data (19 cloud-free FITS files with Seestar S50) to carry out photometry.
The field containing V0419 Mus (aka Nova Mus 2026) and photometry in progress (nova in cross hairs and reference stars in green at top right) is shown above.
Another faint star in the field led to the need for careful photometry aperture sizing:
The result of photometry is shown in the plot below (under the cross hairs): a visual (Tri-Color Green) magnitude of 7.966 (with error 0.058). The visual (Johnson V) observation about 3.5 hours immediately before of 7.943 (with error 0.024) was submitted several hours after mine by an observer in Queensland, and the visual magnitude 8 (using eyeball + binoculars or telescope) was made about 4 hours later by an observer in Botswana.
There were only around 70 visual band observations as of around midday today, not surprising given the weather and the nova’s very southern declination, along with about the same number of observations in red and blue bands.
Nova light curves often appear quite non-descript and messy early on.
The following 1.2 degree finder chart needs to be rotated about 45 degrees clockwise to match the Seestar images above:
It’s a fairly sparse patch of sky.
The AAVSO Variable Star Index VSX record gives more detail about the nova including visual band magnitude range, currently 19 to 7.7. Novae often have pre-eruption magnitudes of 19 or dimmer.
We’ll see what happens next with V0419 Mus, whether it brightens again or continues to decline.
In honour of Artemis II that, as I write this, is less than 12 hours away from Earth re-entry on Day 10 of an amazing return to Luna including being witness to a total solar (vs lunar) eclipse while rounding the far side of the Moon.
Some of my total lunar eclipse pics from Tue Mar 3, mostly with Seestar S50.
Images below:
I have been just a little bit excited about Artemis II, that launched just before 9am on Thursday morning, Adelaide time. It’s been a long time since the Apollo program ended (1972).
I still have an enduring memory of (5 year old me) watching the grainy Apollo 11 landing on our B&W TV after getting to school and being told to go home and watch it in 1969.
Watching the launch on NASA TV (YouTube) and ABC News yesterday morning with Karen was wonderful and scary at the same time, especially waiting for the passage through maximum dynamic pressure (MaxQ), solid rocket booster (SRB) separation, and main engine cutoff (MECO).
Despite a few minor problems leading up to and after launch (e.g. a launch abort system battery sensor issue on the pad, fixing the loo and a potable water system valve in orbit), it was about as flawless as it gets.
Then today, we saw a calm lead up to Trans-Lunar Injection (TLI) that sent Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen on their way around the Moon, further than any human has been, on a free return trajectory back to Earth on day 10, similar to the one taken by Apollo 13.
The crew will get to see a solar eclipse on day 6 when the Orion spacecraft is behind the Moon.
That humanity is going back more than half a century after Apollo is the main thing, with another test flight followed by a landing in 2028. I hope it becomes as much about exploration as anything, but I realise that there are also military and commercial interests.
Here are a few useful links for the Artemis II mission:
Enjoy.
Every so often I share a post from another blogger such as Tamino whose views I respect, e.g. on the topic of climate change.
Today I’m sharing a post from someone else whose views I respect: Michael Dowling. You can find out more about his background in the Bio section below.
I’ve had many interesting and wide-ranging conversations with Michael over the last seven years.
In the essay linked to this post, Michael explores some interesting concepts, including the nature of scientific theories, confusions that sometimes arise in science and philosophy, as well as the significance and implications of living systems and consciousness.
Woven through the essay is the thread of awe and wonder.
I hope you enjoy what Michael has to say as much as I did.
The article (PDF format) can be opened in a new browser tab or downloaded.
After completing a B.Sc. (Hons) degree in chemistry, Michael worked for five years as an analytical chemist, before moving into the field of scientific instruments for twenty years, providing technical sales and support for complex scientific instrumentation (e.g. chromatographs and mass spectrometers), to scientists working in a wide range of fields.
Later in life, Michael studied for ordained ministry in the Uniting Church. He worked as a chaplain in aged care for six years and later was the minister of an Adelaide Hill congregation for five years.
Michael maintains an enduring fascination with science and our lived experience in the world.
Michael Dowling is retired, married and lives in the Blackwood area of Adelaide.
I attended an event organised by South Aussies for Animals today, titled “How to Make Drugs: new models of humane research” which showed a recently created documentary called “How to Make Drugs and Feel Great about Everything” (US) and followed this by a number of speakers from the NSW Animal Justice Party (AJP), SA Health and Medical Research Institute (SAHMRI), and Animal-free Science Advocacy (AFSA).
The basic thesis of How to Make Drugs and Feel Great about Everything was that animal models are unethical and ineffective, noting that 95% of drugs that pass animal testing fail at human clinical trial. Numerous people in the medical research and regulatory areas in the US were interviewed.
One of the people interviewed likened this to an aeroplane company saying their planes would crash 95% of the time, then continuing to spend the same amount of money on the same methods (of management, design, construction).
While I had seen that statistic, I was not aware that adverse drug reactions are the fourth most common cause of deaths in US. I don’t know how that translates to Australia.
On the other hand, it was pointed out that there are very likely drugs that are safe for people but that fail in animal testing so don’t get through to human trials. For example, if animal testing had been the gate for aspirin, it may never have seen the light of day (and for example, aspirin is toxic to dogs).
As one of those interviewed said: we keep wasting time on the wrong models, and while certain cancers in mice, for example, have been cured many times over, we we have no cure for pancreatic cancer, breast cancer, traumatic head injury, stroke in humans, just non-human animals. Another remarked that a problem with fundraising events like running for cancer cure is that it not always clear what the funds raised go towards or whether it’s effective.
Put plainly, billions of dollars spent on animal research is simply wasted because we are different enough from the animal “models” that it matters. The local speaker from SAHMRI later reinforced this by saying that nowhere is this more true than in brain research.
We have already seen a move away from animal testing of cosmetics, shampoo, soap etc.
There are alternatives for medical and drug testing too: organ on a chip, 3D bio-printing of organs based on an individual’s cells (for drug/toxin/disease testing and potentially transplants), and in silico methods such as simulation and machine learning.
Medicine is moving towards an era of personalised medicine, in ways other than bio-printing. Zarina Greenberg from SAHMRI talked about the ability of researchers to now take normal cells, such as skin cells, and to coax them into becoming stem cells (from which they arose) again that can then be differentiated into liver, lung, brain etc cells. For people with particular cancers, these cells can be used to understand personal disease trajectory and potential treatments.
Emma Hurst, from the NSW AJP talked about how she introduced a bill into the NSW parliament to have a right-to-release for animals used in medical experimentation and in particular for dogs and cats to be re-homed. This had multi-partisan support. The bill additionally capped use in animal research before release to 3 years. AJP also introduced (and had approved) a bill to outlaw smoking and forced swim tests which experts giving advice during the creation of the bill declared to be unethical and unscientific. Freedom of information regarding secrecy surrounding primate testing is next.
Rachel Smith of Animal-free Science Advocacy talked about work to review, update and strengthen the 3 Rs framework (replace, reduce, refine) including the addition of rehoming/rehabilitation (after use in research), reproducibility (consistent, repeatable results), and relevance (to human health).
As a former animal model researcher said at the end of the documentary, we should not break the principle of non maleficence, first do no harm, i.e. do not harm innocent beings including non-human animals.
I have found the SeeStar S50 to be fantastic for variable star photometry and general night sky imaging.
For those of us with less spare time than we’d like, chronic back pain, and a willingness to allow our hobby to evolve (or some subset of these), devices in the category of “smart telescope” like the SeeStar, are something of a revolution.
The S50 field of view (0.73 x 1.29 degrees) is great for many deep sky objects (nebulae, star clusters, galaxies) variable stars, asteroids, some comets, Luna, and the Sun. My current primary use cases are deep sky objects and variable stars.
The fields in which variable stars appear are often themselves quite varied and beautiful and that deserves a separate post.
Below is a small gallery of some deep sky images I’ve taken with the S50 from my back yard over the last year or so, each with a catalog designation, name, constellation (unless obvious from the name) and total exposure time (from multiple 10 second images stacked by the device). Noise reduction has been applied to most via the SeeStar app.
