TY - JOUR
T1 - A survey for variable young stars with small telescopes
T2 - IX - evolution of spot properties on YSOs in IC 5070
AU - Herbert, Carys
AU - Froebrich, Dirk
AU - Vanaverbeke, Siegfried
AU - Scholz, Aleks
AU - Eislöffel, Jochen
AU - Urtly, Thomas
AU - Walton, Ivan L
AU - Wiersema, Klaas
AU - Quinn, Nick J
AU - Piehler, Georg
AU - Aimar, Mario Morales
AU - García, Rafael Castillo
AU - Vanmunster, Tonny
AU - Alfaro, Francisco C Soldán
AU - de la Cuesta, Faustino García
AU - Licchelli, Domenico
AU - Perez, Alex Escartin
AU - Mañanes, Esteban Fernández
AU - Ribes, Noelia Graciá
AU - González, José Luis Salto
AU - Futcher, Stephen R L
AU - Nelson, Tim
AU - Dvorak, Shawn
AU - Moździerski, Dawid
AU - Kotysz, Krzysztof
AU - Mikołajczyk, Przemysław
AU - Fleming, George
AU - Phillips, Mark
AU - Vale, Tony
AU - Dubois, Franky
AU - Eggenstein, Heinz-Bernd
AU - Heald, Michael A
AU - Lewin, Pablo
AU - OKeeffe, Derek
AU - Popowicz, Adam
AU - Bernacki, Krzysztof
AU - Malcher, Andrzej
AU - Lasota, Slawomir
AU - Fiolka, Jerzy
AU - Dustor, Adam
AU - Percy, Stephen C
AU - Devine, Pat
AU - Patel, Aashini L
AU - Dickers, Matthew D
AU - Dover, Lord
AU - Grozdanova, Ivana I
AU - Urquhart, James S
AU - Lynch, Chris J R
N1 - CH is supported by the Science and Technology Facilities Council under grant number STFCKent2020DTPST/V50676X/1. This research has been partially supported by the supercomputing infrastructure of the NLHPC (ECM-02) in Chile.
PY - 2024/4/4
Y1 - 2024/4/4
N2 - We present spot properties on 32 periodic young stellar objects in IC 5070. Long term, ∼5 yr, light curves in the V, R, and I-bands are obtained through the HOYS (Hunting Outbursting Young Stars) citizen science project. These are dissected into six months long slices, with 3 months oversampling, to measure 234 sets of amplitudes in all filters. We fit 180 of these with reliable spot solutions. Two thirds of spot solutions are cold spots, the lowest is 2150 K below the stellar temperature. One third are warm spots that are above the stellar temperature by less than ∼2000 K. Cold and warm spots have maximum surface coverage values of 40 per cent, although only 16 per cent of warm spots are above 20 per cent surface coverage as opposed to 60 per cent of the cold spots. Warm spots are most likely caused by a combination of plages and low density accretion columns, most common on objects without inner disc excess emission in K − W2. Five small hot spot solutions have <3 percent coverage and are 3000 – 5000 K above the stellar temperature. These are attributed to accretion, and four of them occur on the same object. The majority of our objects are likely to be accreting. However, we observe very few accretion hot spots as either the accretion is not stable on our timescale or the photometry is dominated by other features. We do not identify cyclical spot behaviour on the targets. We additionally identify and discuss a number of objects that have interesting amplitudes, phase changes, or spot properties.
AB - We present spot properties on 32 periodic young stellar objects in IC 5070. Long term, ∼5 yr, light curves in the V, R, and I-bands are obtained through the HOYS (Hunting Outbursting Young Stars) citizen science project. These are dissected into six months long slices, with 3 months oversampling, to measure 234 sets of amplitudes in all filters. We fit 180 of these with reliable spot solutions. Two thirds of spot solutions are cold spots, the lowest is 2150 K below the stellar temperature. One third are warm spots that are above the stellar temperature by less than ∼2000 K. Cold and warm spots have maximum surface coverage values of 40 per cent, although only 16 per cent of warm spots are above 20 per cent surface coverage as opposed to 60 per cent of the cold spots. Warm spots are most likely caused by a combination of plages and low density accretion columns, most common on objects without inner disc excess emission in K − W2. Five small hot spot solutions have <3 percent coverage and are 3000 – 5000 K above the stellar temperature. These are attributed to accretion, and four of them occur on the same object. The majority of our objects are likely to be accreting. However, we observe very few accretion hot spots as either the accretion is not stable on our timescale or the photometry is dominated by other features. We do not identify cyclical spot behaviour on the targets. We additionally identify and discuss a number of objects that have interesting amplitudes, phase changes, or spot properties.
KW - Stars: formation
KW - Stars: pre-main-sequence
KW - Stars: star spots
KW - Stars: variables: T Tauri
KW - Stars: rotation
U2 - 10.1093/mnras/stae812
DO - 10.1093/mnras/stae812
M3 - Article
SN - 0035-8711
VL - 529
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -