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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

676 results found.

  1. EP250908C: GROND observation of the fading optical counterpart
  2. EP240408A: MASTER optical observations
  3. EP240408a: GROND detection of a candidate counterpart
  4. X-ray transient EP240315a: PRIME near infrared detection
  5. X-ray transient EP240315a: GROND J-band detection
  6. GRB 220711B, GROND observations
  7. GRB 220706A, GROND observations
  8. GRB 220627A, GROND observations
  9. GRB 220117A, GROND observations
  10. GRB 211106A: Swift/UVOT upper limits
  11. GRB 211106A, GROND observations
  12. GRB 210905A, GROND observations
  13. GRB 210901A: GROND observations
  14. GRB 210822A: GROND observations
  15. GRB 210820A: GROND observations
  16. GRB 210731A: continued GROND observations
  17. GRB 210731A: GROND observations
  18. GRB 150428A: late-time radio observations
  19. ZTF21aakruew/AT2021cwd: GROND observations
  20. ZTF21aaeyldq: GROND and CAHA jet break confirmation
  21. ZTF21aaeyldq: GROND observations
  22. GRB 191004A: correction to reported GROND upper limits
  23. GRB191016A GROND observations
  24. GRB 191024A: GROND early upper limits
  25. GRB 191019A: Nanshan-0.6m optical observations
  26. GRB 191019A: Swift/UVOT Detection
  27. GRB 191019A: GROND observations
  28. GRB 191011A: Swift/UVOT Detection
  29. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  30. GRB 191004B: Swift/UVOT Detection
  31. GRB 191004B: GROND Detection of the Optical/NIR Afterglow
  32. GRB 191004A: GROND Upper limits
  33. GRB 190919B: Swift-XRT observations
  34. GRB 190919B: MASTER OT early detection at GROND position
  35. GRB 190919B: GROND detection of the NIR afterglow
  36. GRB 190829A: Liverpool Telescope observations of a slow supernova rise
  37. GRB 190829A: MASTER confirmation of GROND SN
  38. GRB190829A: GROND detection of the accompanying SN
  39. GRB 190829A: Swift/UVOT detection of an optical afterglow with a rise
  40. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  41. LIGO/Virgo S190814bv: DESGW photometry of AT2019npv
  42. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  43. LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
  44. GRB 190613B: GROND Detection of the Optical/NIR Afterglow
  45. LIGO/Virgo S190425z: GROND observations of AT2019ebq/PS19qp
  46. LIGO/Virgo S190408an: GROND Observations of MASTER OT J154209.55-431742.2
  47. GRB 190129B: Swift/UVOT Upper Limits
  48. GRB 190129B: ePESSTO NTT optical observations
  49. GRB 190129B: AstroSat CZTI detection
  50. GRB 190129B: MASTER Global Robotic Net optical observation
  51. GRB 190129B: GROND possible host candidate
  52. GRB 190114A: Swift/UVOT Observations
  53. GRB 190114C: AGILE/MCAL detection
  54. GRB 190114C: X-shooter observations of a highly extinguished afterglow
  55. GRB 190114C: Fermi GBM detection
  56. GRB 190114C: GROND detection of the afterglow
  57. GRB 190114A: GROND detection of the afterglow
  58. GRB 181203A: GROND detection of the afterglow
  59. GRB 181201A: Continued GROND observations show that afterglow is still bright
  60. GRB 181201A: GROND detection of the afterglow and redshift upper limit of z < 3
  61. GROND observations of GRB181110A
  62. GRB 181022A: GROND upper limits
  63. GROND afterglow detection of GRB 181010A
  64. GRB 180809B: GROND Detection of the NIR Afterglow
  65. GRB 180624A: GROND observations
  66. GRB 180620B: Swift/UVOT Detection
  67. GROND observations of GRB 180620B
  68. GROND observations of GRB 180620A
  69. GRB 180613A GROND observations: correction
  70. GRB 180613A GROND observations
  71. GRB 180512A: VLT/HAWK-I NIR Observations
  72. GRB 180512A: GROND upper limits
  73. GRB 180510B: GROND detection in all bands
  74. GRB 180418A: Further GROND observations
  75. GRB 180418A GROND observations
  76. GRB 180325A: GROND observations
  77. GRB 180325A: Global MASTER-Net OT prompt observations
  78. GROND observations of GRB 180316A
  79. GRB 180314A: MASTER-Net OT dtetction
  80. GRB180314A: GROND detection of the afterglow
  81. GRB 180205A: Further GROND Observations reveal Afterglow is still bright
  82. GRB 180205A: GROND detection of the NIR/optical afterglow
  83. GRB 171205A: GROND observations of the optical/NIR transient
  84. GRB 171027A: VLT optical upper limits
  85. GROND observations of GRB 171027A: correction
  86. GROND observations of GRB 171027A
  87. GRB170827A: Further GROND follow-up observations
  88. GROND observations of GRB170827A
  89. LIGO/Virgo G298048: GROND observations of candidate optical counterpart
  90. LIGO/Virgo G298048: NOT near-infrared observations of SSS17a
  91. LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
  92. GROND observations of GRB170604A
  93. GROND observations of GRB 170531B
  94. GRB 170428A: GTC spectroscopic redshift of candidate host galaxy
  95. GRB 170428A: TAROT La Silla observatory optical observations
  96. GRB 170428A: GROND detection of the afterglow
  97. LIGO/Virgo G277583: GROND follow up of ATLAS17cck
  98. GRB 170311A: Further GROND analysis
  99. GRB 170311A: GROND upper limits
  100. GRB170306A: SALT observations

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