In practical terms, when will we know at the earliest that a new large dwarf planet has been discovered?

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#1

Hello again,

I am very excited about the dwarf planets that we will be able to discover with the LSST.

I am not from the field (my field is medicine), so please excuse my ignorance!

Yes, Melissa kindly gave me great links : The Solar System Processing Pipeline page in the Data Preview 0.3 documentation and Section 3.2.2 of the Data Products Definitions Document. And there is also one vidéo in YouTube : Rubin Science Assembly, Apr 24 2025: Solar System, talking about that too. But I haven’t been able to understand how much time it will be needed so the information of a new big dwarf planet comes to me…

I’ve seen that there is an instantly registration of new detected objects, transmitted to the MPC, and daily updated. But in practical terms I haven’t been able to understand the estimated necessary time to get the information that a specific new big dwarf planet has been discovered. I suppose it would be quite fast, like a few weeks, let’s say that if the detection has been in November/December (2025), then it should be at the latest 1 or 2 months later that we get the information…

But I don’t know… so I prefer to ask you experts !

I’m a bit confused as I am not used to all this : data products, DIA, etc. I’ve seen that there is first an immediate 60 seconds data product with alarms to alert brokers so these templates can be rapidly analysed by “users”. Then there is a daily data product (prompt products data base), with a daily update of new discovered objects. And then there is a yearly data product, yearly data release… The prompt (24h) and data release (annual) data products will be able for users to analyze via Rubin Science Platform.

There will be the DP2 datas (from LSST camera decommissioning period previous to the start of the survey) available 6 months later in may 2026 and the DR1 (first year Data Release from the survey) available January 2027.

What does it mean ? Will a hypothetical dwarf planet detected by the telescope in October/November 2025 be identified soon after (days or weeks later) or will we have to wait a full process of analysis before to have this dwarf planet officially announced (like several months later) ?

My worry is that the datas would be registered somewhere and treated later, like 12 months later, or that the full analysis of each new object would take more than 6 months (updated orbit, characteristics of the object, etc.) before to realise this new big object has appeared to our knowledge !

Let’s imagine a hypothetical scenario where there is only one undiscovered TNO with a size of >1600 km. That is larger than Haumea, which is currently the third largest TNO after Pluto and Eris. It would actually have a diameter of 2000 km, which is only slightly smaller than Pluto or Eris (2350 km). But it would be further away.

Semi-major axis Pluto 40 AU and current distance between 30 and 60 AU.

Eris 70 AU and current distance 130 AU (close to aphelion).

And this new object: a = 75-110 AU and current distance between 130 and 200 AU (close to aphelion).

As I learned here thanks to this forum and their kind responses (thank you Lynne, Gloria, and Melissa), this object, whose apparent magnitude is estimated at 21-22, will inevitably be detected (if it exists) before December 2025! (That’s fantastic!)

Either during commissioning (in the fall, i.e., September/October), or when the survey starts in November!

But my question is: when will I be able to find out that an object like this has been found? Indeed, we first need to be able to determine its size and distance in order to realize that it is indeed a large dwarf planet.

So you told me that the mobile object tracking software analyzes the images as soon as they are taken (the pairs of images !).

I imagine that all these images are automatically stored in a database.

But in practical terms, what happens next in chronological order? How long does it take before we know that we have actually discovered this object? Before it is revealed to the public…

I have seen that there are different time frames for accessing “DP1” data preview 1, DP2, DR1 (data release 1), etc.

Who will be responsible for analyzing and classifying all the newly discovered objects?

How will the information about this new object actually reach us? How long can we expect to wait between the shooting of this object in October or November 2025 and the announcement that a very large dwarf planet, almost as big as Pluto, has been discovered? With its characteristics of size, magnitude, distance, etc.

When can I expect to be informed that such an object has been found? (If it exists, of course… and if it was detected by the LSST in October or November)

(Will I have to wait for the information to appear at the Minor Planet Center? Or appear in the media? How long will it take to analyze this object and for the information to be finalized?)

Thank you in advance :pray:

(Sorry for not being more concise in asking this question!)

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#2

I want to know too!

I’m not an academic, just an IT professional with 25 years of experience. I am an amateur astrophotographer and would love to work as a citizen cientist helping find this new discoveries. I don’t have a RSP account but I wanna know when the pictures will be a available to the public. It will be only in the Zooniverse site?

My greatest interests are in new solar system planets and nearest white dwarves, neutron stars and black holes by micro gravitational lenses.

Thanks

#3

Hi @Rabu, thank you for your questions, and thank you, @rggerk, for your interest as well. I will do my best to answer the questions laid out here.

You are correct that the best links to find the information about the detection pipelines for moving objects with LSST are the following:

The Solar System Processing Pipeline runs on a 24-hour cycle and passes linkages of candidate moving object detections (i.e., “tracklets” that each comprise at least two images within a single night) to the Minor Planet Center for formal orbit fitting and release of new discoveries on a daily basis. LSST specifications state that a valid linkage must include at least three tracklets, each from a different night, and all within a 14-day period. In short, this means that it could take 14 days for a linkage of tracklets to be made for a given object before it can be passed onto the Minor Planet Center to get an orbit fit and to be released as a new discovery in the MPCORB catalog that comes out daily. Since all discoveries are made public on this timeline, that will include any new dwarf planets discovered by Rubin’s LSST. Due to the vast number of expected moving object discoveries with Rubin, public announcements of individual discoveries will not be feasible. The best way to keep up-to-date with new discoveries is to monitor the daily MPCORB catalog that will be available on the Rubin Science Platform or the Minor Planet Center’s website.

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#4

Thank you Sarah

Now another thing : well, the same thing, but not from the survey which starts in November, but the first look on June 23 and the DP1 release 1 week later on June 30.

I’ve heard that DP1 will be the data products of the commissioning ComCam campaign. And that the ComCam is already very powerful : limit of magnitude >25. And that all the area available in the autumn (2024) sky has been covered. So it’s kind of a survey before the real survey. Like à général répétition for a concert from à philarmonic orchestra. If you can assist to it you will hear almost the same concert. So here we would have already discovered all biggest objects with the ComCam previous to the LSSTCam survey to start !

So is it that we have discovered already many TNOs and also dwarf planets if they have a magnitude of <23 ? And that it will be announced on the first look event ?

Or at least, to be able to discover it in the data base at MPC or LSST already from June 30 ?

Is the first look event related to the DP1 release from the ComCam data or is it something else, like a presentation to the public of the first images made by LSSTCam in spring 2025 ?

I am confused

But anyway, someone told me that if there is such a big dwarf planet of 21-22 magnitude then the ComCam campaign should have already detected it in autumn 2024 and it will be revealed at the first look or will appear in the DP1 released data from june 30, 1 week later.

Do you agree ?
Would you give me more information about that ?

Thx

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#5

Hi @Rabu, you are correct that DP1 will be released on June 30 and will include data from the “ComCam” commissioning camera. More information about DP1 and the DP1 data products can be found in this forum post.

The Rubin First Look event on June 23, which will be the public presentation of the first images from LSSTCam is separate from the release of DP1, which will contain the data from ComCam commissioning that occurred prior to the installation of the LSSTCam.

Specific objects contained within DP1 will be made public with the release on June 30.

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#6

Thank you for your answer

Now I come with new informations so I have to update my question

Someone gave me false hope saying we would discover that object I’m waiting for (very large dwarf planet similar size of Pluto) with the commissioning (dp1 ComCam or dp2 LSSTCam) because we will cover all the areas… which is false from what I understood. DP1 is just about 7 minuscules areas. And dp2 I don’t know the area but I don’t care as the sector I’m interested in will not be covered as it will be (it has been already) in spring. (Except if this commissioning campaign lasts until at least august, when the sector would appear again in the night sky. I don’t know I couldn’t get that information in the internet and neither could I find about the areas tested during LSSTCam commissioning (DP2))

So let’s just talk about the définitive survey that will start in November.

I read that the vast majority of solar system mobile objects would be detected the first year (and from my deduction it would be even the first month… if the area is visible in the night sky at this period)

So let’s say that the biggest still undiscovered dwarf planet, which would have (hypothesis) à similar size to Pluto and Eris (and wouldnt have been detected before by the commissioning campaigns because its sector wouldnt have been covered) would be detected already 1 month later in December 2025…

How much additional time would it be necessary so I get the information that this object has been identified ??

I read that to be “detected” (and therefore registered in the MPC data base) it must have been seen 3 times in a period of 14 days. So let’s imagine it happened in December 2025.

Then it would be still shot over and over again every 4 nights. And its new position would be integrated in the database MPCORB, to slowly realise what kind of orbit it has.

Then, I suppose, from the movement it has, some smart astronomers would calculate finally its characteristics : size, brilliance, distance, speed, apparent movement, a small part of its orbital elements (estimates of semi major axis, aphelion, inclination, eccentricity, etc.)

But how long would it take to finally estimate its size (approximately) ? (“Approximately” with a reasonable margin of error of +/- 500 km, but at least knowing it will be one of the biggest dwarf planets, >1500 km.)

And should we wait the date of release of the data to know (January 2027 for DR1 :weary:) or will we be able to ask for this information before ? Like every month we could ask someone somewhere or some data base to check if such object bigger than 1700 km diameter has appeared ?

Thx

#7

Hi Rabu – it is confusing because we have multiple stages of commissioning.

DP1 is from the comcam commissioning period with the LSSTComCam camera, and has a very limited sky area. This will NOT include the area you are interested in around Cetus.

DP2 will be from the lsstcam commissioning period, with the LSSTCam camera, which is only just in the early phases of its commissioning period. The commissioning science survey will start in the next few weeks. The area to be included in this commissioning survey isn’t 100% decided, as it will depend on many things including how well the observatory is functioning. It is likely that it will include the area you have asked about, around the ecliptic near declination +2 degrees or so. We have not yet publicly released the LSSTCam commissioning survey plans, as they are still under final development.

Now, your question becomes slightly complicated. Simply imaging the area and running the standard pipelines (SSP) - that would likely happen relatively quickly and the results from the standard pipelines are released rapidly (as you say, could potentially be as early as December 2025, but might be a little later). However, identifying a very distant dwarf planet may be tricky if it is moving very slowly – this may require running non-standard pipelines for detecting very slowly moving objects. This makes it a bit harder for me to say how quickly such an object would be found and announced. It could potentially be as early as spring 2026, but it’s also possible that it would take more than one year to identify truly slowly moving objects.

However, once we do find an object, we already have some idea of its distance and orbit (these are required in order for the MPC to announce it). Once you have a distance, and a brightness in an image, you already have some estimate of its size. Thus, as soon as you know there is something there, you would be able to estimate its size.

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#8

Hi Lynne
Thank you again for your answer

I have to say that this forum is really appreciable to be able to communicate with astronomers and especially the ones of the staff of LSST

Believe me, if not, for an external non-astronomer it’s very difficult !

About your answer :

DP1: yes I realised (in the note 011 I think ) that the area would be only 7 tiny spots.

About DP2: I thought it would be in spring 2025. It’s a good surprise that it will be in summer 2025. The sector Pisces/Cetus is in the night sky from July to January. From august to December you can have it at the zenith of the sky for more than 2-3 hours (in the Chilean site of the Rubin ). If you haven’t decided 100% yet I just can give you the good advice of looking in a specific sector in Pisces/cetus :
À rectangle of maximum 200 square degrees with these ECLIPTIC coordinates (you’ll have to convert in equatorial coordinates) and not with the J2000.0 system but with the true equinoxe one (J2000.0 will be I think 21’ minutes of degree less or 0.35deg less) :

RA : 10.75deg to 15.25deg (4.5 degrees wide)
(In J2000.0 : 10.4deg to 14.9deg)

DEC : -16.7deg to +16.7deg for the simple option (150deg^2), but the bigger option would be even better :

DEC: -22.22 deg to +22.22 deg (200deg^2)
But if even the simple option is too big for you (but I don’t think it would be the case with wide images of 9.5 deg^2 !) then it’s still very good even with reduced DEC:

DEC : -11.11deg to +11.11deg (100 deg^2). You’ll need only 7 or 8 shots in vertical (latitude or DEC) and only 2 shots in horizontal (longitude or RA) so 14 or 16 shots maximum to cover this sector…

If you want to know why, we can talk in private.

If you have the possibility to cover this sector in DP2 then… do it ! (But only if you will take pairs of shots like in the definitive survey to be able to track mobile objects ! If not… forget it ! Let’s wait the definitive survey to start already in November !)

:man_shrugging:

PS : thank you for all your explanations : yes it’s a slow dwarf planet : 0.15 to 0.20 degrees per year current movement) Actually it is near its aphelion at a distance of 130 to 200 AU, its semi major axis is between 75 and 115 AU and its révolution time is around 700-1100 years…
(Don’t ask how I can tell this… but trust me ! :sunglasses:)

.

#9

Hi @Rabu, thanks for the continued discussion. As moderator this week, I’m going to mark @ljones’ response as the solution. Please feel free to open a new topic for new questions at any time.