Verena Fürnkranz
PhD student in Astronomy

I am an Austrian PhD student at the Max Planck Institute for Astronomy in Heidelberg (Germany) as part of the IMPRS-HD program. I work on the dispersal of open clusters, stellar associations and streams in the Milky Way disk, using astrometric and photometric data provided by the Gaia mission. Before this, I did my Bachelor and Master in the Department of Astrophysics at the University of Vienna (Austria).

• Curriculum Vitae
• ADS publication list

Research

The distribution of young stars in the Milky Way disk is clustered across a wide range of scales, from compact bound objects (open clusters) to loose associations to stellar streams that extend over several hundred parsecs. Subsequently, most stars disperse from their birth siblings, spreading in orbit and orbital phase and transitioning to become 'field stars’.

Hence, the orbits of stars - when combined with their ages and abundances - encode much of the formation history of the Milky Way. I use the revolutionary 6D data provided by Gaia and to study the 'clumpy' orbit space structure of stars in our extended solar neighbourhood (<1 kpc around the Sun), with the aim to address and answer the following questions:

• What is the origin of substructure in the orbit distribution?
• On what orbits are stars born?
• How clumpy is the distribution of birth places of stars?
• At what rate do young clusters disperse and what does this tell us about the transition to the Galactic field population?

Selected Publications

Likelihood isochrone fitting

Fürnkranz, Rix, Coronado & Seeburger 2023 (accepted by ApJ)

We have developed a method to derive ages of stellar action-angle groups by projecting their action-angle distribution into 5D position-parallax-proper motion space and draw CMDs from the entire Gaia catalog. We then performed a likelihood isochrone fitting, which accounts for widely varying distances and reddenings, outliers and binaries, sparsely populated main sequence turn-offs, and the possible presence of an intrinsic age spread within a stellar population.

'Pearls on a string'

ADS: Coronado, Fürnkranz & Rix 2022

We have identified algorithmically the most prominent ensembles of stars in the solar neighborhood that are clustered in orbit and orbital phase (action-angle) space. We then explored the orbit phase distribution of all stars in the same 'orbit patch' as any of these action-angle groups, and discovered that very commonly numerous other distinct orbit-phase overdensities are found on very similar orbits, merely at different orbital phases, like 'pearls on a string'.

Coma Berenices tidal tails

ADS: Fürnkranz, Meingast & Alves 2019

We have studied the well-known open cluster Coma Berenices and a previously unknown moving group of stars in its velocity and spatial neighborhood. We unveiled the long predicted tidal tails of the open cluster Coma Berenices, an effect of cluster disruption due to the tidal field of the Milky Way. Furthermore, we found that both groups will share essentially the same volume when their centers will be at their closest in 13 Myr. This will result in the mixing of two unrelated populations with different metallicities, which we estimated to be not a rare event in the Milky Way disk.

120° stellar stream

ADS: Meingast, Alves & Fürnkranz 2019

We have discovered a dynamically cold, coeval stellar stream (known as 'Meingast 1' or 'Pisces-Eridanus') in the immediate solar vicinity at a distance of only 100 pc. We identified the stream as an overdensity in the 3D velocity space of all stars within 300 pc of the Sun, using the revolutionary position and velocity data provided by the Gaia mission. The stream shows an elongated structure with a length of at least 400 pc, while being vertically much more confined. We speculate that the stream might be a remnant of a disrupted cluster, or more likely the outcome of a stellar association, shaped into a thin stream by interactions with the Galaxy’s tidal field.

Personal

Besides Astronomy, you'll often find me outdoors. I'm a big fan of sports, enjoying everything from volleyball to hiking mountains, and in winter, you'll find me skiing or going on ski tours. I bike several times a week, and occasionally I like running too. I also travel a lot, and I like to end up in less visited destinations sometimes.

Get In Touch

I'm always happy to chat. If you are interested in more about my research, or just want to say hi, feel free to reach out. The best way to contact me is through email.