I forgot to post this a couple weeks back! It was the 20-year anniversary of one of the first exoplanets
ever found - and it was lurking around a pulsar!
Draugr (Norse for "undead creatures") is one of three planets that orbits the pulsar Lich (also an undead creature).
The official name of the system is PSR B1257+12 and it features the three planets in orbit around the nasty pulsar.
It's located about 1900 light-years away in the constellation Virgo and was discovered in 1994, two years after the first two exoplanets were found around Lich.
The EXTREMELY NEAT thing about Draugr is that, to date, it remains the least massive exoplanet ever discovered, even when compared to the planets in our Solar System - which tells us something!
Found through pulsar timing, its mass is only ~2 times the lunar mass.
Measuring acceleration in 26 pulsars, authors report:
Sun experiencing 1mm/s/yr acceleration away from Galactic centre, comparable to the gravitational force of a Jupiter-mass object 400 AU away (not Planet 9).
Mass enclosed within 8kpc of Galactic centre is ~2.3 times larger than accepted models.
I need to read (and understand this a bit better) but I think that the uncertainties in some of the distance and parallax measurements of the pulsars might introduce big enough overall uncertainties that could affect the outcomes reported here. Will be watching how this plays out!
A pulsar timing array, but instead of actual real pulsars, send out a bunch of precise atomic clocks in all directions of the Solar System and measure their 'ticks' at a central receiving station.
This idea reported in this pre-print aims to assess the 0.1–10 Hz GW band.
It's been a few months since I've done some proper science writing for #SpaceAustralia (Phd Lyfe) but thought this new paper drop was interesting to write about!
Australian astronomers have used radio waves to look deep into the heart of the Globular Cluster 47 Tucanae & found an undiscovered radio source.
The newly found radio source could potentially be the first evidence of an intermediate-mass black hole in the core of a Globular Cluster, or a pulsar that is real close to the centre.
#Pulsars are magnetized, rotating neutron stars. Beams of radiation from their magnetic poles swipe past the observer, resulting in characteristic pulsing radio patterns.
The fastest pulsar we know, PSR J1748−2446ad, rotates at 716 times/sec or 43000 times/min.
Very neat follow-up study of the radio detections of millisecond pulsars in the Omega Centauri core, with CHANDRA, finding correlation between spider pulsar companion mass and X-ray luminosity.
The redbacks give off more X-rays!
Omega Cent. is a super interesting Globular Cluster to study with pulsars, as it is so much more massive than other Milky Way GCs. Some folks think it is the remnant component of a former, now cannibalised galaxy - which makes probing the dynamics and binary configurations in the core interesting!
NASA reveals hundreds of city-sized objects shooting light into space.
Mashable reports: "Scientists using the agency's Fermi Gamma-ray Space Telescope have announced the discovery of nearly 300 unique neutron stars, called pulsars."
Currently on my last ever scheduled observation of my problem child pulsar.
Bittersweet moment - I’ll miss observing it but also I’ve done soooo many hours of observations.
Data coming down at Murriyang (Parkes) and I’ve logged in from home.
It’s being extra nice tonight!
Have covered a full year of high cadence observing with the problem child - I got awarded the time on my telescope during my Masters and have carried through to my PhD.
Very excited to now be processing this data, for the very project I started!
This might be interesting to those of you following the story of the stochastic nanohertz-frequency regime gravitational wave background. A follow on from the big announcement at the end of June.
The IPTA third data release is currently in the works!
Been playing with a little Python script I’m writing that shows a 3D map of the millisecond pulsars observed by our team (PPTA), relative to Earth.
This vid shows the perspective of looking inwards from about 15,000 light years from Earth (blue dot) with surrounding millisecond pulsars (red dots) based on their RA + Dec + distance.
Another Murriyang (Parkes radio telescope) observation under my belt tonight.
Nearing the end of the semester and almost a year of the project I set up to learn more about my problem child pulsar - a highly magnetised, rapidly rotating neutron star that threw its toys out of the pram.
I’ve already started the analysis (see my next post below) but it’s gonna take a while to get all the data ready.
These are webcam images through our observing portal.
We have a fascinating interview with #astronomy legend Dame Jocelyn Bell-Burnell. Discoverer of #pulsars and passionate advocate of women in science. #astrodon
We have a fascinating interview with #astronomy legend Dame Jocelyn Bell-Burnell. Discoverer of #pulsars and passionate advocate of women in science. #astrodon
We have a fascinating interview with #astronomy legend Dame Jocelyn Bell-Burnell. Discoverer of #pulsars and passionate advocate of women in science. #astrodon
We have a fascinating interview with #astronomy legend Dame Jocelyn Bell-Burnell. Discoverer of #pulsars and passionate advocate of women in science. #astrodon