ddahlen

7 ms·

31.
by ddahlen 1y ago
It is inside jupiter's orbit now, it will come inside Mars for a time. It is almost on the plane of the solar system, not very inclined. I linked an orbit viewer above if you want to look.
32.
by ddahlen 1y ago
This one is coming in fast, it has an eccentricity of over 6 with the current fits. For point of reference, 1I and 2I have eccentricities of 1.2 and 3.3. Right now it is mostly just a point on the sky, it is difficult to tell if it is activ
33.
by ddahlen 1y ago
I posted a couple of months ago: https://github.com/dahlend/kete Research grade orbit calculations for asteroids and comets (rust/python). I began working on this when I worked at caltech on the Near Earth Object
34.
by ddahlen 1y ago
As I said, just an order of magnitude estimate for many non-adaptive optics telescopes.
35.
by ddahlen 1y ago
The atmosphere is always an issue, we can correct for many of the effects using adaptive optics, but there are always limits. The advantage you get from going bigger on the ground is that you are making a bigger "bucket" to put ph
36.
by ddahlen 1y ago
I have been working in astronomy for a few years now and I recently have gone back to school for a PhD in orbital dynamics. Rubin is going to make a big difference in our knowledge of the asteroid belt, it will likely more than triple the s
37.
Show HN: Accurate orbital dynamics for asteroids/comets(github.com)
3 points by ddahlen 1y ago|0 comments
38.
Show HN: rust based orbit calculations for asteroids/comets(github.com)
1 points by ddahlen 1y ago|0 comments
39.
by ddahlen 1y ago
I got a bit too excited with this one, this is may not be a full on dwarf planet, but it is a very large object. There are only a small number (about 10-20) objects in our solar system of this size. Its the first big one we have found in a
40.
by ddahlen 1y ago
If you want to view the orbit: https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2017%...
41.
by ddahlen 1y ago
Depends on the albedo, if the H magnitude is a good measurement, then it is probably between 300-700km. These are rough bounds, its highly dependent on how reflective it's surface is (albedo). With an orbit somewhere around 28k years,
42.
Possible new dwarf planet found in our solar system(minorplanetcenter.net)
163 points by ddahlen 1y ago|99 comments
43.
by ddahlen 1y ago
The minor planet center is the clearing house of observations of objects in our solar system. They have announced a new dwarf planet today. This object appears to be in a very eccentric orbit (0.948), and with an H magnitude of 3.55, so it
44.
by ddahlen 1y ago
I have been in and out of the academic world my entire career. I have worked as a programmer/engineer for two universities and a national lab, and worked at a startup founded by some professors. There is huge uncertainty with the peopl
45.
by ddahlen 1y ago
Basically all observations of solar system objects besides the big planets are going to be unresolved point sources. IE: We don't have telescopes which can resolve most objects into an image. An example, Hubble famously had to image a
46.
by ddahlen 1y ago
2 big reasons, first is that wobbles which we normally observe require that the star move enough to be detected on a shorter time scale. IE: if the orbit takes 100 years and we look twice in 5 years, the planet will have only moved 5% of a
47.
by ddahlen 1y ago
Most images are registered by finding the location of known stars from a high resolution catalog such as GAIA. So you fit centroids of all stars in an image, then do a search of Gaia sources in that location and do some sort of linear or hi
48.
by ddahlen 1y ago
Thank you for the offer! Unfortunately the PhD has already sunk its claws in. I should have some flashy stuff to show off in a 2-3 months (I have a conference talk coming I have to prepare material for).
49.
by ddahlen 1y ago
I've never really dabbled in youtube. I have several projects/papers I am working on using this code, I have thought about writing some blog posts as I publish those. But a PhD is going to be a major time sink, we will see what ha
50.
by ddahlen 1y ago
I am about to begin a PhD in astronomy. Until last month I was working at Caltech for 3 years on code which calculates orbits of asteroids to high precision. This code is being used on several NASA telescopes now to predict when they will i
51.
by ddahlen 2y ago
I cannot speak for the community, I don't have a very broad contact list for this sort of thing. Among the few people I know this has definitely drummed up some interest though (there are not nearly as many people who study asteroids a
52.
by ddahlen 2y ago
Wikipedia's source is: https://cneos.jpl.nasa.gov/sentry/details.html#?des=2024%20Y... It is currently moving away from us as it does its little dance around the sun. It will likely soon be too faint to see going
53.
by ddahlen 2y ago
yeah it has corrections for GR of sun/jupiter/earth, along with J2 terms for those, and the 5 most massive asteroids. Typically matches JPL Horizons results to sub 100km over a decade for vast majority of objects. Optionally accep
54.
by ddahlen 2y ago
I work on asteroid/comet orbit calculations for my day job. I had not actually seen this paper before, though I have done some detective work in old Palomar images in the past: https://caltech-ipac.github.io/kete/t
55.
by ddahlen 2y ago
I can tell you how I do it, but again I am not an impact study person. It helps to understand a bit of the background of how we fit orbits in general: 1) someone with a telescope sees something moving (typically these days these are bigger
56.
by ddahlen 2y ago
It's a bit of both, observing has uncertainty in a lot of places, if you are on the ground you get atmospheric effects, imprecision of timing, imprecision of optics, etc etc. You are also observing an object where you dont know how far
57.
by ddahlen 2y ago
I work on the Near Earth Object Surveyor space telescope (NEO Surveyor) writing simulation code which predicts which objects we will see. This one has drummed up a bit of interest due to its (relatively) high chance of impact. I actually s
58.
by ddahlen 2y ago
I have recently managed to open source some of our tools which we use on the NEO Surveyor mission to simulate all of the asteroids. However my code lacks any real sort of visualizations: https://github.com/Caltech-IPAC/
59.
by ddahlen 2y ago
There are sort of two major camps in the field, the astronomers and the people who fly satellites. Having the thing you are measuring able to talk to you and get doppler measurements of its velocity is invaluable for orbit determination, so
60.
by ddahlen 2y ago
We have spotted a grand total of 2 interstellar objects, they were moving faster, but are many orders of magnitude less numerous then the local stuff. Just doing some back of the envelope calculations, looks like Omuamua was moving about 16

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