The observation of intrinsically different emergences for large and small active regions

Bibcode
1984SoPh...92..161G
DOI
10.1007/BF00157243
de la Rosa, I. G.
Bibliographical reference

Solar Physics (ISSN 0038-0938), vol. 92, May 1984, p. 161-172.

Advertised on:
5
1984
Number of authors
1
IAC number of authors
1
Citations
15
Refereed citations
14
Description
The analysis of high-resolution H-alpha and white-light observations on the emergence of 73 active regions shows an intrinsically different behavior for both the large and small ones. The small active regions (magnetic flux of approximately 5 x 10 to the 21st Mx) display circular structures of supergranular size with pores only at the borders, whereas the large active regions show elongated structures with pores which develop at the center and later migrate towards the extremes. These observations are used to suggest two different models for the emergence of these two kinds of active regions: the small ones are produced by the superficial convective concentration of loosely packed flux and the large ones are the result of tightly wound flux ropes.
Type
Refereed
Astrometry
Solar activity
Solar granulation

It may interest you

  • Refereed
    Constraining the TeV gamma-ray emission of SN 2024bch, a possible type IIn-L from a red supergiant progenitor: Multiwavelength observations and analysis of the progenitor
    We present very high-energy optical photometry and spectroscopic observations of SN 2024bch in the nearby galaxy NGC 3206 (∼20 Mpc). We used gamma-ray observations performed with the first Large-Sized Telescope (LST-1) of the Cherenkov Telescope Array Observatory (CTAO) and optical observations with the Liverpool Telescope (LT) combined with data
    Abe, K. et al.

    Advertised on:

    10
    2025
    Bibcode
    2025A&A...702A.125A
    Citations
    0
  • Refereed
    An ALMA Band 7 survey of SDSS/Herschel quasars in Stripe 82: I. The properties of the 870 micron counterparts
    Context. Over the past 15 years, studies of quasars in the far-infrared (FIR) have reported host luminosities ranging from 10 12 to 10 14 L ⊙. These luminosities, often derived from Herschel/SPIRE photometry, suggest star formation rates (SFRs) of up to several thousand M ⊙ yr ‑1, positioning them among the most luminous starburst galaxies in the
    Hatziminaoglou, E. et al.

    Advertised on:

    10
    2025
    Bibcode
    2025A&A...702A.183H
    Citations
    0
  • Refereed
    Transit timing variations in HIP 41378: CHEOPS and TESS confirm a non-transiting sixth planet in the system
    In multiple-planet systems, gravitational interactions of exoplanets could lead to transit timing variations (TTVs), whose amplitude becomes significantly enhanced when planets are in or near mean-motion resonances (MMRs), making them more easily detectable. In cases where both TTVs and radial velocity (RV) measurements are available, combined
    Leonardi, P. et al.

    Advertised on:

    10
    2025
    Bibcode
    2025A&A...702A.211L
    Citations
    0