# Seligman 2025: Discovery and Preliminary Characterization of a Third Interstellar Object: 3I/ATLAS

> Darryl Z. Seligman, Marco Micheli, Davide Farnocchia et al., 2025. 3 records on Mysteries Department cite it. The primary record of 3I's discovery and…

Source: https://mysteriesdept.com/sources/SRC0CSKBD3C762B/discovery-and-preliminary-characterization-of-a-third  
Publisher: Mysteries Department  
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[Sources](https://mysteriesdept.com/sources)[1I/'Oumuamua](https://mysteriesdept.com/mysteries/oumuamua)Seligman 2025

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# Discovery and Preliminary Characterization of a Third Interstellar Object: 3I/ATLAS

Darryl Z. Seligman, Marco Micheli, Davide Farnocchia et al., 2025. _The Astrophysical Journal Letters_.

The discovery paper for the third interstellar object, found by the ATLAS survey on 1 July 2025: eccentricity about 6.1, perihelion 1.36 au, inclination 175 degrees, excess velocity 58 km/s, a compact coma in deep CFHT and VLT stacks, little light-curve variation over four days and a red spectral slope like primitive Solar System bodies. ApJL 989, L36.

**1I/'Oumuamua** Articledoi: **[10.3847/2041-8213/adf49a](https://doi.org/10.3847/2041-8213/adf49a)** Checked against the original0

## What it's used for here

The primary record of 3I's discovery and first properties.

## Cited by on this site 3 records

[The ATLAS survey finds the third interstellar object, 3I/ATLAS](https://mysteriesdept.com/mysteries/oumuamua/events/EVT0CSKBYNW3TEQ/the-atlas-survey-finds-the-third-interstellar-object-3i)

EVT

[1I/'Oumuamua](https://mysteriesdept.com/mysteries/oumuamua)

The mystery article

MYS

[Is 'Oumuamua typical of interstellar objects, or a rare kind?](https://mysteriesdept.com/mysteries/oumuamua/questions/QST0CSKC0MC0R58/is-oumuamua-typical-of-interstellar-objects-or-a-rare-kind)

Question

QST

## Cite it

```
Seligman, D. Z., Micheli, M., Farnocchia, D., Denneau, L., Noonan, J. W., Hsieh, H. H., Santana-Ros, T., Tonry, J., & Meech, K. J. (2025). Discovery and Preliminary Characterization of a Third Interstellar Object: 3I/ATLAS. The Astrophysical Journal Letters. https://doi.org/10.3847/2041-8213/adf49a
```

[Read it free at doi.org](https://doi.org/10.3847/2041-8213/adf49a)

Key

**SRC** 0CSKBD3C762B

Kind

Journal article

Rights

The publisher's

Kept

27 Oct 2026, for editors

Checked

Against the published article

Added by

[apollo](https://mysteriesdept.com/u/apollo)

The record

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