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00:00:00 --> 00:00:02 Anna: Hello everyone. Welcome to Astronomy
00:00:02 --> 00:00:05 AstroDailyPod. A molecule
00:00:05 --> 00:00:07 nobody had ever found in space, sitting
00:00:07 --> 00:00:10 around a star that hasn't finished being
00:00:10 --> 00:00:10 born.
00:00:11 --> 00:00:13 Avery: A dead star that would glow green if only
00:00:13 --> 00:00:16 you could get close enough to look at it.
00:00:16 --> 00:00:19 And six pulsars that were hiding in old
00:00:19 --> 00:00:21 Australian radio data the whole time.
00:00:21 --> 00:00:24 Anna: Plus a supernova caught just days
00:00:24 --> 00:00:26 after it went off when the universe was
00:00:26 --> 00:00:29 barely more than a billion years old. And an
00:00:29 --> 00:00:31 update on Hera's big breaking burn.
00:00:32 --> 00:00:34 Avery: It's Friday 16th October
00:00:34 --> 00:00:37 2026, and this is Astronomy AstroDailyPod
00:00:38 --> 00:00:41 series five, episode 206. I'm, um,
00:00:41 --> 00:00:41 Avery.
00:00:41 --> 00:00:43 Anna: And I'm Anna.
00:00:43 --> 00:00:44 Let's get into it.
00:00:44 --> 00:00:46 Avery: Ready when you are. Why don't you lead things
00:00:46 --> 00:00:47 off, Anna?
00:00:47 --> 00:00:50 Anna: Our lead story today is about chemistry,
00:00:51 --> 00:00:53 and it comes from the Atacama Large
00:00:53 --> 00:00:56 Millimetre Submillimeter Array on
00:00:56 --> 00:00:58 Alma, high on the Chognator Plateau
00:00:58 --> 00:01:01 in northern Chile. A large
00:01:01 --> 00:01:04 international programme called compass,
00:01:04 --> 00:01:07 which stands for Complex Organic Molecules
00:01:07 --> 00:01:10 in Protostars with ALMA Spectral Surveys,
00:01:10 --> 00:01:13 has published its first results this month as
00:01:13 --> 00:01:16 uh, seven papers in the journal Astronomy and
00:01:16 --> 00:01:17 Astrophysics.
00:01:17 --> 00:01:20 Avery: And the headline is A molecule that has never
00:01:20 --> 00:01:21 been detected in space Before.
00:01:22 --> 00:01:24 Anna: That's right, but let's set the scene first,
00:01:25 --> 00:01:27 because the survey itself is the reason the
00:01:27 --> 00:01:30 discovery was possible. Compus pointed
00:01:30 --> 00:01:33 Alma at 11 nearby protostars.
00:01:33 --> 00:01:36 These are young sun like stars that are still
00:01:36 --> 00:01:38 wrapped in the cloud of gas and dust they're
00:01:38 --> 00:01:41 forming from. The programme took more than a
00:01:41 --> 00:01:43 hundred hours of telescope time.
00:01:43 --> 00:01:45 Avery: And instead of looking for one molecule at a
00:01:45 --> 00:01:48 time, they recorded white slices of the
00:01:48 --> 00:01:49 spectrum all at once.
00:01:50 --> 00:01:52 Anna: Exactly. Every molecule in space
00:01:53 --> 00:01:55 emits at its own set of radio frequencies, a
00:01:55 --> 00:01:58 kind of barcode. A broadband spectral
00:01:58 --> 00:02:00 survey records thousands of those lines
00:02:00 --> 00:02:03 simultaneously. And then the work is
00:02:03 --> 00:02:05 untangling which lines belong to which
00:02:05 --> 00:02:08 molecule. The programme is led by Jes
00:02:08 --> 00:02:10 Jorgensen at the Niels Bohr Institute in
00:02:10 --> 00:02:12 Copenhagen, with co leads in the United
00:02:12 --> 00:02:15 States, France, Switzerland and South Korea.
00:02:15 --> 00:02:18 Jorgensen describes the results as completely
00:02:18 --> 00:02:20 new insight into the chemistry around the
00:02:20 --> 00:02:21 very youngest stars.
00:02:22 --> 00:02:25 Avery: Let's take the two big results in turn. The
00:02:25 --> 00:02:27 first one is about methanol masers.
00:02:27 --> 00:02:30 Anna: Methanol is the simplest alcohol.
00:02:30 --> 00:02:33 It's one carbon, one oxygen and four
00:02:33 --> 00:02:36 hydrogens. And in space it
00:02:36 --> 00:02:38 matters because it is a stepping stone to
00:02:38 --> 00:02:40 bigger organic molecules.
00:02:41 --> 00:02:44 A maser is the microwave cousin of a laser.
00:02:44 --> 00:02:47 Under the right conditions, the molecules
00:02:47 --> 00:02:49 amplify radiation at one very
00:02:49 --> 00:02:52 specific frequency and you get an intensely
00:02:52 --> 00:02:54 bright narrow signal.
00:02:55 --> 00:02:57 Avery: And um, methanol masers are well known around
00:02:57 --> 00:02:58 massive stars.
00:02:59 --> 00:03:01 Anna: They are what a Study led by
00:03:01 --> 00:03:04 Jaeheng Jiang, a graduate student at Seoul
00:03:04 --> 00:03:07 National University, found is that methanol
00:03:07 --> 00:03:10 maser emission shows up in more than half
00:03:10 --> 00:03:12 of the low mass protostars in the sample.
00:03:13 --> 00:03:16 That was not expected for stars on the way to
00:03:16 --> 00:03:19 being something like rsut. The team
00:03:19 --> 00:03:21 also identified a new maser transition of
00:03:21 --> 00:03:24 methanol and found it associated with another
00:03:24 --> 00:03:27 organic molecule, acetaldehyde.
00:03:28 --> 00:03:30 Avery: So it may be common and we simply weren't
00:03:30 --> 00:03:31 looking hard enough.
00:03:32 --> 00:03:34 Anna: That's the team's reading that this
00:03:34 --> 00:03:37 emission may be a normal part of the earliest
00:03:37 --> 00:03:40 stages and only shows up once the
00:03:40 --> 00:03:42 observations are sensitive enough.
00:03:43 --> 00:03:45 Avery: Now the result in the headline this
00:03:45 --> 00:03:48 Anna: one is led by Arno Balas at the
00:03:48 --> 00:03:51 Max Planck Institute for Radio Astronomy.
00:03:51 --> 00:03:53 The target is a protostar called
00:03:53 --> 00:03:56 IRAS4A2 in the Perseus
00:03:56 --> 00:03:59 molecular cloud about 1000 light years away
00:03:59 --> 00:04:02 and around it, the team made the first
00:04:02 --> 00:04:05 interstellar detection of fully deuterated
00:04:05 --> 00:04:07 methanol. Its formula is
00:04:07 --> 00:04:08 CD3OD.
00:04:09 --> 00:04:11 Avery: Explain deuterium for us.
00:04:11 --> 00:04:14 Anna: Deuterium is heavy hydrogen.
00:04:14 --> 00:04:17 A normal hydrogen nucleus is a single
00:04:17 --> 00:04:20 proton. Deuterium has a proton and
00:04:20 --> 00:04:23 a neutron. Chemically, it behaves almost the
00:04:23 --> 00:04:25 same, so it can take hydrogen's place in a
00:04:25 --> 00:04:28 molecule. Ordinary methanol has four
00:04:28 --> 00:04:30 hydrogen atoms. Fully deuterated
00:04:30 --> 00:04:33 methanol has all four, replaced by deuterium.
00:04:34 --> 00:04:36 The paper notes it's the first molecule with
00:04:36 --> 00:04:39 four deuterium atoms ever identified in the
00:04:39 --> 00:04:40 interstellar medium.
00:04:40 --> 00:04:43 Avery: And deuterium is rare,
00:04:43 --> 00:04:44 very rare.
00:04:45 --> 00:04:47 Anna: Across the cosmos, there are only about two
00:04:47 --> 00:04:49 deuterium atoms for every 100
00:04:50 --> 00:04:52 hydrogen atoms. If molecules simply
00:04:52 --> 00:04:55 picked up deuterium at that ratio, you would
00:04:55 --> 00:04:57 essentially never see one with four of them.
00:04:58 --> 00:05:00 So the fact that this molecule exists at all
00:05:00 --> 00:05:03 in enough quantity for ALMA to detect
00:05:03 --> 00:05:05 tells you something has been concentrating
00:05:05 --> 00:05:07 deuterium very strongly.
00:05:07 --> 00:05:10 Avery: How do you prove you found a molecule
00:05:10 --> 00:05:13 in a spectrum that crowded with
00:05:13 --> 00:05:16 Anna: many lines, not one? A single
00:05:16 --> 00:05:19 spectral line could be a coincidence, because
00:05:19 --> 00:05:22 a protostar like this has thousands of lines
00:05:22 --> 00:05:24 from dozens of molecules overlapping.
00:05:24 --> 00:05:27 So the test is whether every line that the
00:05:27 --> 00:05:30 lab says this molecule should produce appears
00:05:30 --> 00:05:32 at the right frequency with sensible relative
00:05:32 --> 00:05:35 strengths and with nothing better explaining
00:05:35 --> 00:05:38 it. The paper reports 10 lines of
00:05:38 --> 00:05:40 fully deuterated methanol clearly detected
00:05:40 --> 00:05:41 under those criteria.
00:05:42 --> 00:05:44 Avery: And this has been a long hunt.
00:05:44 --> 00:05:47 Anna: It has Methanol with a single
00:05:47 --> 00:05:50 deuterium was first found in space in
00:05:50 --> 00:05:52 1988 toward Orion.
00:05:52 --> 00:05:55 Versions with two and three deuterium atoms
00:05:55 --> 00:05:58 followed in the early 2000s around another
00:05:58 --> 00:05:59 young protostar,
00:05:59 --> 00:06:01 IRAS16.
00:06:01 --> 00:06:04 The forward deuterium version is the last
00:06:04 --> 00:06:06 step on that ladder, and until now, there had
00:06:06 --> 00:06:09 been no robust identification of it anywhere
00:06:09 --> 00:06:10 in the interstellar medium.
00:06:11 --> 00:06:13 Avery: And this is where it becomes a clock rather
00:06:13 --> 00:06:15 than a curiosity.
00:06:15 --> 00:06:18 Anna: Right before a star switches on, the
00:06:18 --> 00:06:21 cloud core it forms from is extraordinarily
00:06:21 --> 00:06:24 cold, around 10 degrees above absolute zero.
00:06:25 --> 00:06:27 In those conditions, carbon monoxide freezes
00:06:27 --> 00:06:30 onto dust grains and the chemistry in the gas
00:06:30 --> 00:06:32 tilts in favour of handing deuterium to
00:06:32 --> 00:06:35 whatever forms next. Methanol forms on the
00:06:35 --> 00:06:38 icy grains by adding hydrogen atoms one
00:06:38 --> 00:06:41 at a time, to frozen carbon monoxide.
00:06:41 --> 00:06:44 The colder and older the core, the more of
00:06:44 --> 00:06:46 those added atoms are deuterium.
00:06:46 --> 00:06:49 Avery: So the amount of deuterium in the methanol
00:06:49 --> 00:06:52 reflects when and in what conditions
00:06:52 --> 00:06:53 it formed?
00:06:54 --> 00:06:56 Anna: That's the idea the paper sets out. The
00:06:56 --> 00:06:59 deuterium fraction can reflect the time when
00:06:59 --> 00:07:01 a molecule formed. Then the
00:07:01 --> 00:07:04 protostar switches on and warms its
00:07:04 --> 00:07:06 surroundings. The ice evaporates, the
00:07:06 --> 00:07:09 methanol comes off the grains into the gas
00:07:09 --> 00:07:12 and ALMA can see it. What we're reading in
00:07:12 --> 00:07:15 that gas is an effect of fossil record of the
00:07:15 --> 00:07:17 cold phase before the star existed.
00:07:18 --> 00:07:20 Avery: There's a nice callback here for regular
00:07:20 --> 00:07:21 listeners.
00:07:21 --> 00:07:24 Anna: There is. In episode 200, we
00:07:24 --> 00:07:27 covered the deuterium to hydrogen ratio in
00:07:27 --> 00:07:30 the water of the interstellar comet 3I
00:07:30 --> 00:07:33 Atlas. And before that, in episode
00:07:33 --> 00:07:36 194, molecular nitrogen used
00:07:36 --> 00:07:38 as a thermometer for where that comet formed.
00:07:38 --> 00:07:41 Same principle, isotopes and ices as
00:07:41 --> 00:07:44 thermometers and clocks for places we
00:07:44 --> 00:07:45 can never visit.
00:07:46 --> 00:07:48 Avery: Now, caveats, because there are some
00:07:48 --> 00:07:49 important ones.
00:07:50 --> 00:07:53 Anna: Yes. First, the deuterium pattern
00:07:53 --> 00:07:55 itself is a puzzle. The team detected
00:07:55 --> 00:07:57 every form of methanol with lab data
00:07:57 --> 00:08:00 available, and the apparent deuterium
00:08:00 --> 00:08:03 fraction rises as you go from 1 deuterium
00:08:03 --> 00:08:06 to 2, 3 and 4. That's a pattern
00:08:06 --> 00:08:08 seen in other young stars too. But the
00:08:08 --> 00:08:10 current chemical models of cold cores don't
00:08:10 --> 00:08:13 reproduce it. And the new detection makes the
00:08:13 --> 00:08:15 mismatch worse, not better.
00:08:15 --> 00:08:18 Avery: So it's a result that breaks the models
00:08:18 --> 00:08:20 rather than confirming them.
00:08:20 --> 00:08:23 Anna: It is. Second, the authors themselves
00:08:23 --> 00:08:25 suspect their measurement of ordinary
00:08:25 --> 00:08:27 methanol is too low, possibly because the
00:08:27 --> 00:08:30 emission is clumpy and that would shift the
00:08:30 --> 00:08:32 ratios. Third, this is one
00:08:32 --> 00:08:35 protostar. And fourth, the obvious one.
00:08:35 --> 00:08:38 Organic molecules are chemistry, not biology.
00:08:39 --> 00:08:41 Jorgensen frames the bigger question as how
00:08:41 --> 00:08:44 these ingredients might shape conditions on
00:08:44 --> 00:08:46 planets that form later. That's a question,
00:08:46 --> 00:08:47 not a finding.
00:08:48 --> 00:08:51 Avery: And, um, these are the first papers. The full
00:08:51 --> 00:08:53 data set is still being analysed.
00:08:53 --> 00:08:56 Anna: Seoul National University's Jung Unlee, one
00:08:56 --> 00:08:58 of the CO leads, says they're just beginning
00:08:58 --> 00:09:01 to tap the richness of the data. A key goal
00:09:01 --> 00:09:03 is working out whether differences between
00:09:03 --> 00:09:06 young stars come from where they were born
00:09:06 --> 00:09:08 or develop as they grow up.
00:09:08 --> 00:09:11 Avery: And the southern angle, two of them,
00:09:11 --> 00:09:14 Anna: honestly labelled Alma itself,
00:09:14 --> 00:09:17 sits at 5 metres in the Chilean Andes.
00:09:18 --> 00:09:20 And three of the seven papers focus on
00:09:20 --> 00:09:22 another protostar called BHR71,
00:09:23 --> 00:09:25 a dark globule deep in the southern sky
00:09:26 --> 00:09:29 from Sydney. It is circumpolar and climbs to
00:09:29 --> 00:09:32 almost 60 degrees. It never rises for our
00:09:32 --> 00:09:34 listeners in Los Angeles, New York or London.
00:09:35 --> 00:09:37 Perseus, where the heavy methanol was found,
00:09:38 --> 00:09:40 is the opposite. Low for us, almost
00:09:40 --> 00:09:42 overhead for California.
00:09:43 --> 00:09:45 Avery: Both hemispheres in one survey. Lovely.
00:09:45 --> 00:09:48 Anna: Right, on to our next story
00:09:49 --> 00:09:49 from
00:09:49 --> 00:09:52 Avery: chemistry around a star being born to the
00:09:52 --> 00:09:53 colours of stars that have died.
00:09:54 --> 00:09:56 Astronomers at the University of Warwick have
00:09:56 --> 00:09:58 published the study this week in RAS
00:09:58 --> 00:10:01 Techniques and Instruments, with a lovely
00:10:01 --> 00:10:04 title, any colour you like and
00:10:04 --> 00:10:04 a claim
00:10:04 --> 00:10:06 Anna: nobody has made before.
00:10:07 --> 00:10:10 Avery: The first star that would genuinely look
00:10:10 --> 00:10:12 green. Here's a setup.
00:10:12 --> 00:10:15 For most stars, colour is just temperature.
00:10:15 --> 00:10:18 Cooler stars look orange. Stars, like the
00:10:18 --> 00:10:21 sun, look white. The hottest look pale blue.
00:10:22 --> 00:10:24 Physicists call that a perfect radiator,
00:10:24 --> 00:10:27 like iron glowing in a blacksmith's forge.
00:10:28 --> 00:10:31 Anna: And white dwarfs, the dense cores left
00:10:31 --> 00:10:34 behind by sun like stars, were assumed to
00:10:34 --> 00:10:35 follow the same rule.
00:10:35 --> 00:10:38 Avery: They were. But the team led by Mark
00:10:38 --> 00:10:40 Hollins points out that the coolest white
00:10:40 --> 00:10:43 dwarf atmospheres are astonishingly dense,
00:10:43 --> 00:10:46 around 1 gramme per cubic centimetre, about
00:10:46 --> 00:10:48 the density of water, and millions of times
00:10:48 --> 00:10:51 denser than the sun's visible surface. Trace
00:10:51 --> 00:10:54 elements in that dense helium absorb light
00:10:54 --> 00:10:56 across much wider bands than they normally
00:10:56 --> 00:10:58 would, and that pushes the colour off the
00:10:58 --> 00:10:59 usual track.
00:10:59 --> 00:11:02 Anna: So how do you see the colour of a star
00:11:02 --> 00:11:03 nobody can get close to?
00:11:04 --> 00:11:07 Avery: You don't. And this is the key caveat.
00:11:07 --> 00:11:10 No white dwarf is close enough for its colour
00:11:10 --> 00:11:13 to be seen directly. The team took spectra
00:11:13 --> 00:11:15 astronomers already have, and ran them
00:11:15 --> 00:11:17 through a model of human colour vision to
00:11:17 --> 00:11:19 calculate what colour the light would look
00:11:19 --> 00:11:22 like to your eye. And the green one,
00:11:23 --> 00:11:23 it's called
00:11:23 --> 00:11:27 WDJ1336435.
00:11:28 --> 00:11:30 It's around 4 degrees Celsius
00:11:30 --> 00:11:33 and it has swallowed rocky material from its
00:11:33 --> 00:11:36 own old planetary system that has
00:11:36 --> 00:11:38 loaded its atmosphere with calcium, lithium
00:11:38 --> 00:11:41 and sodium. Sodium in that dense
00:11:41 --> 00:11:43 atmosphere absorbs the orange part of the
00:11:43 --> 00:11:46 spectrum and what's left comes out chartreuse
00:11:46 --> 00:11:49 green. Hollins invites you to imagine
00:11:49 --> 00:11:51 standing on a planet and looking up at a
00:11:51 --> 00:11:52 green star.
00:11:53 --> 00:11:55 Anna: Which connects to the polluted white dwarf we
00:11:55 --> 00:11:57 covered in episode 201.
00:11:58 --> 00:12:01 Avery: Exactly the same family dead stars eating the
00:12:01 --> 00:12:03 remains of their planets. At the other
00:12:03 --> 00:12:06 extreme, WD J1011
00:12:06 --> 00:12:09 2845 just 48 light years
00:12:09 --> 00:12:11 away, has dredged carbon up uh, from its
00:12:11 --> 00:12:14 core. Carbon molecules squeeze almost all
00:12:14 --> 00:12:17 of its light beyond 600 nanometers and it
00:12:17 --> 00:12:20 uh, may be the reddest star ever recorded. A
00:12:20 --> 00:12:21 ah, deep salmon pink.
00:12:22 --> 00:12:24 Anna: But the average white dwarf
00:12:24 --> 00:12:25 is white,
00:12:25 --> 00:12:27 Avery: which is a nice correction.
00:12:28 --> 00:12:30 The team looked at the 151 white dwarfs
00:12:30 --> 00:12:33 within 20 parsecs about 65 light years.
00:12:34 --> 00:12:37 Five had unusual colours, two yellow
00:12:37 --> 00:12:40 and three pink. So roughly one in 30.
00:12:40 --> 00:12:43 For the rest the median colour temperature is
00:12:43 --> 00:12:46 about 6 Kelvin, which reads as
00:12:46 --> 00:12:49 white. Astronomers have tended to think of
00:12:49 --> 00:12:51 white dwarfs as blue only because the hot
00:12:51 --> 00:12:54 blue ones are brighter. So they dominate
00:12:54 --> 00:12:56 surveys that pick stars by brightness.
00:12:56 --> 00:12:59 Anna: That's a selection effect we've talked about
00:12:59 --> 00:13:01 before. Catalogues are detection
00:13:02 --> 00:13:04 limits, not censuses.
00:13:04 --> 00:13:07 Avery: And one honest audience note. The green
00:13:07 --> 00:13:10 star sits in the far northern sky,
00:13:10 --> 00:13:13 circumpolar from London and New York and it
00:13:13 --> 00:13:14 never rises from Sydney.
00:13:14 --> 00:13:16 It's far too faint to see the colour in any
00:13:16 --> 00:13:19 telescope anywhere, so nobody's missing
00:13:19 --> 00:13:19 out.
00:13:20 --> 00:13:22 Anna: Our next story is built on old data.
00:13:23 --> 00:13:26 Two new preprints, both posted to the
00:13:26 --> 00:13:29 archive on 8 October report
00:13:29 --> 00:13:32 Pulsars found by going back through archived
00:13:32 --> 00:13:34 Observations from Meiriang
00:13:34 --> 00:13:37 CSIRO's Parkes Radio Telescope in New
00:13:37 --> 00:13:37 South Wales.
00:13:38 --> 00:13:40 Avery: And they're not in our galaxy.
00:13:40 --> 00:13:43 Anna: They're in the Magellanic Clouds, the two
00:13:43 --> 00:13:46 satellite galaxies of the Milky Way, around
00:13:46 --> 00:13:49 160 to 200 light
00:13:49 --> 00:13:51 years away. Only just over
00:13:51 --> 00:13:54 1% of all known radio pulsars live there
00:13:54 --> 00:13:57 because at that distance they're faint and
00:13:57 --> 00:13:58 hard to catch.
00:13:58 --> 00:14:00 Avery: Remind us what a pulsar is.
00:14:00 --> 00:14:03 Anna: A neutron star, the collapsed
00:14:03 --> 00:14:05 core of a uh, massive star
00:14:06 --> 00:14:09 spinning and sweeping a beam of radio waves
00:14:09 --> 00:14:12 across us like a lighthouse. We
00:14:12 --> 00:14:14 see a pulse each time the beam goes past.
00:14:15 --> 00:14:17 The faint ones are buried in noise and you
00:14:17 --> 00:14:20 find them by folding the data, stacking
00:14:20 --> 00:14:23 it at a trial spin period until the pulses
00:14:23 --> 00:14:24 add up.
00:14:24 --> 00:14:26 Avery: So what did they do differently?
00:14:27 --> 00:14:29 Anna: The first paper is led by Rahul
00:14:29 --> 00:14:32 Sangar with co authors including Matthew
00:14:32 --> 00:14:34 Bales of Swinburne University of Technology.
00:14:35 --> 00:14:38 They reprocessed the original Parkes
00:14:38 --> 00:14:40 multibeam surveys of the Magellanic Clouds
00:14:41 --> 00:14:43 with search techniques tuned for faint
00:14:43 --> 00:14:45 pulsars with very narrow pulses
00:14:46 --> 00:14:48 folding candidates right down near the noise
00:14:48 --> 00:14:51 floor. They found six new pulsars
00:14:51 --> 00:14:54 five are in the Large Magellanic Cloud, and
00:14:54 --> 00:14:56 one of those spins once every 3.8
00:14:56 --> 00:14:59 seconds, the slowest pulsar known in
00:14:59 --> 00:15:02 either cloud, and the sixth seen
00:15:02 --> 00:15:04 toward the Small Magellanic Cloud. But it
00:15:04 --> 00:15:06 turns out to be in our own galaxy in the
00:15:06 --> 00:15:09 foreground. The new finds bring the count of
00:15:09 --> 00:15:11 radio pulsars known in the Large magellanic
00:15:11 --> 00:15:14 Cloud to 49. The team also finds that as
00:15:14 --> 00:15:16 a population, the Magellanic Cloud pulsars
00:15:16 --> 00:15:19 look consistent with ordinary pulsars in the
00:15:19 --> 00:15:19 Milky Way.
00:15:19 --> 00:15:21 Avery: And, um, the second paper.
00:15:21 --> 00:15:23 Anna: That's Weiyu Wing and Rahul Sengar. They went
00:15:23 --> 00:15:25 back through archival Park's pointings at
00:15:25 --> 00:15:27 supernova remnants in the Small Magellanic
00:15:27 --> 00:15:30 Cloud and found a Pulsar now called PSR
00:15:30 --> 00:15:33 J010372. It
00:15:33 --> 00:15:36 spins once every 1.33 seconds, which makes it
00:15:36 --> 00:15:38 the slowest radio pulsar known in the small
00:15:38 --> 00:15:40 cloud. Its dispersion measure, a measure of
00:15:40 --> 00:15:42 how much ionised gas the signal has passed
00:15:42 --> 00:15:44 through, is the second highest of any pulsar
00:15:44 --> 00:15:47 there. And it was missed by earlier searches
00:15:47 --> 00:15:48 of exactly the same data.
00:15:48 --> 00:15:49 Avery: Caveats.
00:15:49 --> 00:15:51 Anna: Both are preprints.
00:15:51 --> 00:15:54 The pulsars don't yet have precise timing
00:15:54 --> 00:15:56 positions, so the locations are
00:15:56 --> 00:15:59 approximate in one case, uncertain by
00:15:59 --> 00:16:02 several arcminutes. The authors say
00:16:02 --> 00:16:05 plainly that the next step is follow up and
00:16:05 --> 00:16:07 the bigger lesson they draw is about method.
00:16:08 --> 00:16:10 A faint signal that sits just under a
00:16:10 --> 00:16:13 threshold in one search can be recovered by a
00:16:13 --> 00:16:15 better one. There's a, uh.
00:16:15 --> 00:16:17 Avery: Both hemispheres twist here too.
00:16:17 --> 00:16:20 Anna: There is a separate paper Posted on
00:16:20 --> 00:16:23 the 12th reprocesses the green Bank
00:16:23 --> 00:16:26 Telescope's Northern Sky Survey with the
00:16:26 --> 00:16:29 same kind of approach and reports 51
00:16:29 --> 00:16:32 new pulsars. And. And it cites the Magellanic
00:16:32 --> 00:16:35 Cloud work as part of its motivation. But
00:16:35 --> 00:16:37 the clouds themselves are a southern story
00:16:38 --> 00:16:41 from Sydney. Both are circumpolar and
00:16:41 --> 00:16:44 they never rise from Los Angeles, New York
00:16:44 --> 00:16:45 or London.
00:16:45 --> 00:16:48 Avery: Asking an old question of archive data.
00:16:49 --> 00:16:51 We keep coming back to that one,
00:16:51 --> 00:16:54 Anna: proving yet again that old
00:16:54 --> 00:16:57 data can be good data when looked at
00:16:57 --> 00:16:58 through fresh eyes.
00:16:59 --> 00:17:01 Avery: Next, a star that exploded when the Universe
00:17:01 --> 00:17:04 was about 1.2 billion years old and was
00:17:04 --> 00:17:06 caught by the James Webb Space Telescope
00:17:06 --> 00:17:08 within days of going off.
00:17:08 --> 00:17:11 Anna: This one's a preprint, so let's flag that up
00:17:11 --> 00:17:11 front.
00:17:11 --> 00:17:14 Avery: Yes, it was posted on 29th September
00:17:14 --> 00:17:17 by Ming Yang, Zhang Yui Shen and
00:17:17 --> 00:17:19 colleagues from the Nexus programme, a web
00:17:19 --> 00:17:21 survey that keeps returning to the same patch
00:17:21 --> 00:17:24 of sky near the North Ecliptic Pole, coming
00:17:24 --> 00:17:27 back to the same field over and over is what
00:17:27 --> 00:17:29 lets you spot something new appearing.
00:17:29 --> 00:17:30 Anna: And something did.
00:17:31 --> 00:17:34 Avery: On 7 August this year, a new point of
00:17:34 --> 00:17:36 light appeared in a star forming galaxy at a
00:17:36 --> 00:17:39 redshift of 5.
00:17:39 --> 00:17:41 It's catalogued as at
00:17:41 --> 00:17:43 2026ABCK.
00:17:44 --> 00:17:46 It's faint, around magnitude
00:17:46 --> 00:17:49 27.5, and the team estimates it was
00:17:49 --> 00:17:51 seen roughly four to 10 days after the
00:17:51 --> 00:17:53 explosion in the star's own time.
00:17:54 --> 00:17:57 Anna: That phrase in the star's own
00:17:57 --> 00:17:58 time matters.
00:17:58 --> 00:18:01 Avery: Here it does. At a redshift
00:18:01 --> 00:18:03 of about five, time itself appears
00:18:03 --> 00:18:06 stretched by a factor of six. So
00:18:06 --> 00:18:09 four to ten days at uh, the explosion shows
00:18:09 --> 00:18:11 up to us as, uh, somewhere around a month to
00:18:11 --> 00:18:14 two months. That stretching is
00:18:14 --> 00:18:17 actually helpful because it slows the early
00:18:17 --> 00:18:20 fast changing phase down enough to catch.
00:18:21 --> 00:18:22 Anna: And what does it look like?
00:18:22 --> 00:18:25 Avery: Hot and bright for its age. The
00:18:25 --> 00:18:28 team says it's hotter and more luminous than
00:18:28 --> 00:18:31 normal type 2 supernovae at comparable early
00:18:31 --> 00:18:34 phases. Those are the explosions of
00:18:34 --> 00:18:36 massive stars whose cores collapse.
00:18:36 --> 00:18:39 Its position off centre between two
00:18:39 --> 00:18:42 parts of its host galaxy also fits a massive
00:18:42 --> 00:18:44 star rather than a black hole flaring in the
00:18:44 --> 00:18:47 core. The authors call it the
00:18:47 --> 00:18:50 first robustly detected transient at a
00:18:50 --> 00:18:52 redshift around 5 or beyond in a
00:18:52 --> 00:18:54 field without gravitational lensing.
00:18:55 --> 00:18:58 Anna: That's a distinction from SN EOS earlier this
00:18:58 --> 00:18:58 year.
00:18:59 --> 00:19:02 Avery: Right. SN EOS at a slightly higher
00:19:02 --> 00:19:04 redshift was magnified by a gravitational
00:19:05 --> 00:19:07 lens and confirmed with a spectrum.
00:19:07 --> 00:19:10 This one was found in an ordinary
00:19:10 --> 00:19:13 blank field, which says that regular
00:19:13 --> 00:19:16 high cadence web surveys can catch these
00:19:16 --> 00:19:17 young explosions directly.
00:19:18 --> 00:19:21 Anna: And the caveat with this one,
00:19:21 --> 00:19:21 there
00:19:21 --> 00:19:24 Avery: is no spectrum of the transient.
00:19:24 --> 00:19:27 Without one, its classification stays
00:19:27 --> 00:19:30 uncertain. And the authors say it could also
00:19:30 --> 00:19:32 be a super luminous supernova caught on the
00:19:32 --> 00:19:35 way up. So a strong candidate, a
00:19:35 --> 00:19:38 good demonstration of the method and, um, not
00:19:38 --> 00:19:39 M yet a confirmed type.
00:19:40 --> 00:19:43 Anna: Time for some quick hits. First, ESA's
00:19:43 --> 00:19:45 Hera, its first braking manoeuvre,
00:19:45 --> 00:19:48 BRM1 was scheduled for early Thursday
00:19:48 --> 00:19:51 morning, European time. Three thrusters
00:19:51 --> 00:19:54 firing together for 93 minutes to shed
00:19:54 --> 00:19:56 a few hundred metres per second relative to
00:19:56 --> 00:19:59 the asteroid pair Didymos and Dimorphos
00:19:59 --> 00:20:02 at the time of recording. ESA hasn't yet
00:20:02 --> 00:20:04 published confirmation, so we'll bring you
00:20:04 --> 00:20:05 the result as soon as it's out.
00:20:05 --> 00:20:08 Avery: And ESA was going to check it through New
00:20:08 --> 00:20:10 Norcia in Western Australia.
00:20:10 --> 00:20:13 Anna: That's right. The second shorter burn,
00:20:13 --> 00:20:16 around 31 minutes, is set for Thursday the
00:20:16 --> 00:20:19 22nd. Then three small manoeuvres late in
00:20:19 --> 00:20:21 the month before arrival in November.
00:20:21 --> 00:20:24 Meanwhile, at the space station
00:20:25 --> 00:20:28 SpaceX's CRS 35 cargo Dragon
00:20:28 --> 00:20:31 docked on Thursday about 27 minutes
00:20:31 --> 00:20:33 past 10 in the morning US Eastern Time.
00:20:34 --> 00:20:37 That's 27 past 1 on Friday morning in
00:20:37 --> 00:20:38 Sydney. It brought more than
00:20:38 --> 00:20:41 6 pounds of supplies, including
00:20:41 --> 00:20:44 the last two rollout solar arrays which are
00:20:44 --> 00:20:46 due to be installed on spacewalks. NASA will
00:20:46 --> 00:20:49 preview on Tuesday with Anil Menon and
00:20:49 --> 00:20:51 Canada's Joshua Kutryk.
00:20:51 --> 00:20:52 Avery: And um, Monday.
00:20:53 --> 00:20:56 Anna: Monday is the eve of Japan's Martian Moons
00:20:56 --> 00:20:59 exploration mission. MMX is set to
00:20:59 --> 00:21:02 launch on an H3 rocket from Tanegashima at
00:21:02 --> 00:21:04 4:41 minutes past 4 on Tuesday morning
00:21:04 --> 00:21:05 Japan time.
00:21:06 --> 00:21:08 That's 6:41 on Tuesday morning in
00:21:08 --> 00:21:11 Sydney and Monday afternoon in the Americas.
00:21:11 --> 00:21:14 It's going to Phobos to bring back a sample
00:21:14 --> 00:21:17 which is due to land in Australia in 2031.
00:21:17 --> 00:21:18 Full preview on Monday.
00:21:19 --> 00:21:22 Avery: Let's look up now. The moon
00:21:22 --> 00:21:25 is a waxing crescent this evening and it
00:21:25 --> 00:21:28 reaches first quarter on Sunday the 18th
00:21:28 --> 00:21:30 at 12 minutes past 4 in the afternoon
00:21:31 --> 00:21:34 universal time. That's 3:12
00:21:34 --> 00:21:36 on Monday morning in Sydney, around
00:21:37 --> 00:21:39 midday on Sunday in New York and
00:21:39 --> 00:21:41 Sunday morning in Los Angeles
00:21:42 --> 00:21:45 and full moon Monday the 26th
00:21:45 --> 00:21:48 at uh, 11 minutes past 4 universal time.
00:21:49 --> 00:21:51 That's the afternoon of the 26th in Sydney,
00:21:52 --> 00:21:55 just after midnight on the 26th in New York
00:21:55 --> 00:21:58 and the evening of the 25th in in Los
00:21:58 --> 00:22:00 Angeles. A reminder for UK
00:22:00 --> 00:22:03 listeners that your clocks go back on
00:22:03 --> 00:22:06 Sunday the 25th while North America
00:22:06 --> 00:22:08 changes on the 1st of November.
00:22:08 --> 00:22:11 Anna: The big event this week is a meteor
00:22:11 --> 00:22:11 shower.
00:22:12 --> 00:22:15 Avery: The Orionids, made of dust shed by
00:22:15 --> 00:22:17 Hallie's comet peak on the night of the
00:22:17 --> 00:22:19 21st into the 22nd.
00:22:20 --> 00:22:22 They're a modest shower, but the good news
00:22:22 --> 00:22:25 this year is that the gibbous moon sets
00:22:25 --> 00:22:28 before dawn in all four of our cities at
00:22:28 --> 00:22:30 about 2:50 in London, 10 past three
00:22:30 --> 00:22:33 in New York, 20 past three in Los
00:22:33 --> 00:22:35 Angeles, and just after half past three in
00:22:35 --> 00:22:38 Sydney. The window between moonset and
00:22:38 --> 00:22:40 dawn is the one to use.
00:22:40 --> 00:22:43 Anna: And this one works for both hemispheres.
00:22:44 --> 00:22:46 Avery: It does because the radiant near
00:22:46 --> 00:22:49 Orion's raised club sits close to the
00:22:49 --> 00:22:52 celestial equator. At nautical Dawn on the
00:22:52 --> 00:22:54 22nd, it's about 40 degrees up from Sydney,
00:22:55 --> 00:22:57 52 from London, 62 from New York and
00:22:58 --> 00:23:00 68 from Los Angeles. Northern skies
00:23:00 --> 00:23:03 have the edge, but Sydney's very much in the
00:23:03 --> 00:23:03 game.
00:23:03 --> 00:23:05 Anna: What about the evening?
00:23:06 --> 00:23:09 Avery: This one favours the south. Mercury is a
00:23:09 --> 00:23:11 lovely evening object for us
00:23:12 --> 00:23:14 tonight. Half an hour after sunset, it's
00:23:14 --> 00:23:17 about 19 degrees up in the west from Sydney
00:23:17 --> 00:23:20 at about magnitude 0, and it doesn't set
00:23:20 --> 00:23:23 until after 9. From Los Angeles, it's
00:23:23 --> 00:23:25 only 5 degrees up. From New York 3.
00:23:25 --> 00:23:27 And from London, it's already below the
00:23:27 --> 00:23:28 horizon at that point.
00:23:29 --> 00:23:31 Anna: And Venus is leaving.
00:23:32 --> 00:23:34 Avery: Venus is heading for inferior conjunction,
00:23:35 --> 00:23:37 passing between us and the sun around the
00:23:37 --> 00:23:38 24th.
00:23:39 --> 00:23:41 From Sydney tonight, it's only about 7
00:23:41 --> 00:23:43 degrees up at civil dusk and dropping fast
00:23:44 --> 00:23:47 in the north. It's already gone. It comes
00:23:47 --> 00:23:49 back as a morning star next month.
00:23:49 --> 00:23:50 Anna: Saturn's still around.
00:23:52 --> 00:23:54 Avery: Saturn, just past opposition, is in the
00:23:54 --> 00:23:57 east after dark and climbs all evening
00:23:57 --> 00:24:00 at, uh, dusk Tonight it's about 19 degrees up
00:24:00 --> 00:24:03 from Sydney and lower further north. But
00:24:03 --> 00:24:05 give it an hour or two wherever you are. The
00:24:05 --> 00:24:08 moon passes about 6 degrees from Saturn on
00:24:08 --> 00:24:10 the 24th, and the mornings
00:24:10 --> 00:24:11 Anna: belong to the north.
00:24:12 --> 00:24:15 Avery: They do. Mars and Jupiter keep
00:24:15 --> 00:24:17 closing in the predawn sky.
00:24:17 --> 00:24:20 They're about 10 degrees apart on the 22nd,
00:24:20 --> 00:24:23 and they'll be just over a degree apart on
00:24:23 --> 00:24:25 the 16th of November. At nautical
00:24:25 --> 00:24:28 dawn on the 22nd, Jupiter is about
00:24:28 --> 00:24:31 50 degrees up and Mars nearly
00:24:31 --> 00:24:33 60. From New York and Los Angeles
00:24:34 --> 00:24:37 from Sydney, both are only around 20 to
00:24:37 --> 00:24:40 25 degrees up. And our stories
00:24:40 --> 00:24:43 today, a nicely balanced week.
00:24:43 --> 00:24:45 The Magellanic Clouds, home of those new
00:24:45 --> 00:24:48 pulsars, and the Southern Protostar
00:24:48 --> 00:24:51 BHR 71, are circumpolar from
00:24:51 --> 00:24:53 Sydney and never rise from the north.
00:24:53 --> 00:24:56 The green white dwarf and the Perseus Cloud
00:24:56 --> 00:24:59 are northern targets. Neither the pulsars
00:24:59 --> 00:25:01 nor the green star is anything you'd see by
00:25:01 --> 00:25:04 eye. So the sky's best offer this week is
00:25:04 --> 00:25:06 the Orionids together.
00:25:07 --> 00:25:10 Anna: And our standing reminder, never look at
00:25:10 --> 00:25:12 Avery: the sun directly or through binoculars, a
00:25:12 --> 00:25:15 telescope or a camera. Without a proper solar
00:25:15 --> 00:25:17 filter certified to the ISO
00:25:17 --> 00:25:19 123122 standard.
00:25:20 --> 00:25:23 Sunglasses are not enough and eye damage can
00:25:23 --> 00:25:24 happen without any pain.
00:25:24 --> 00:25:27 Anna: That's the episode. Heavy
00:25:27 --> 00:25:30 methanol around a newborn star. The first
00:25:30 --> 00:25:31 green star.
00:25:32 --> 00:25:34 Six pulsars recovered from the Parkes archive
00:25:34 --> 00:25:37 and another from the small cloud. And a
00:25:37 --> 00:25:39 supernova caught days old at
00:25:39 --> 00:25:40 redshift 5.
00:25:41 --> 00:25:44 Avery: Plus HERA's braking burns, a new delivery at
00:25:44 --> 00:25:47 the space station. And the Orionids to look
00:25:47 --> 00:25:48 forward to.
00:25:48 --> 00:25:51 Anna: If you've got a question about any of today's
00:25:51 --> 00:25:53 stories, send it through the contact form at.
00:25:53 --> 00:25:55 Ah. Astronomydaily.IO
00:25:56 --> 00:25:58 listener questions have shaped segments
00:25:58 --> 00:26:01 before and we'd love more. You'll find us
00:26:01 --> 00:26:03 as astrodaily Pod on social media.
00:26:03 --> 00:26:05 Avery: We're back tomorrow with the weekend wrap and
00:26:05 --> 00:26:08 on Monday with the MMX launch eve. Until
00:26:08 --> 00:26:09 then, clear skies.
00:26:09 --> 00:26:10 Anna: I'm Anna.
00:26:11 --> 00:26:14 Avery: And I'm Avery. This has been Astronomy
00:26:14 --> 00:26:17 AstroDailyPod part of the bytes.com podcast
00:26:17 --> 00:26:19 network. Clear skies, everyone.
00:26:19 --> 00:26:20 Astronomy Day
00:26:22 --> 00:26:23 Stories we told.
00:26:30 --> 00:26:31 The stories.
00:26:39 --> 00:26:39 Were told.