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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"

675 results found.

  1. EP240408A: MASTER optical observations
  2. EP240408a: GROND detection of a candidate counterpart
  3. X-ray transient EP240315a: PRIME near infrared detection
  4. X-ray transient EP240315a: GROND J-band detection
  5. GRB 220711B, GROND observations
  6. GRB 220706A, GROND observations
  7. GRB 220627A, GROND observations
  8. GRB 220117A, GROND observations
  9. GRB 211106A: Swift/UVOT upper limits
  10. GRB 211106A, GROND observations
  11. GRB 210905A, GROND observations
  12. GRB 210901A: GROND observations
  13. GRB 210822A: GROND observations
  14. GRB 210820A: GROND observations
  15. GRB 210731A: continued GROND observations
  16. GRB 210731A: GROND observations
  17. GRB 150428A: late-time radio observations
  18. ZTF21aakruew/AT2021cwd: GROND observations
  19. ZTF21aaeyldq: GROND and CAHA jet break confirmation
  20. ZTF21aaeyldq: GROND observations
  21. GRB 191004A: correction to reported GROND upper limits
  22. GRB191016A GROND observations
  23. GRB 191024A: GROND early upper limits
  24. GRB 191019A: Nanshan-0.6m optical observations
  25. GRB 191019A: Swift/UVOT Detection
  26. GRB 191019A: GROND observations
  27. GRB 191011A: Swift/UVOT Detection
  28. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  29. GRB 191004B: Swift/UVOT Detection
  30. GRB 191004B: GROND Detection of the Optical/NIR Afterglow
  31. GRB 191004A: GROND Upper limits
  32. GRB 190919B: Swift-XRT observations
  33. GRB 190919B: MASTER OT early detection at GROND position
  34. GRB 190919B: GROND detection of the NIR afterglow
  35. GRB 190829A: Liverpool Telescope observations of a slow supernova rise
  36. GRB 190829A: MASTER confirmation of GROND SN
  37. GRB190829A: GROND detection of the accompanying SN
  38. GRB 190829A: Swift/UVOT detection of an optical afterglow with a rise
  39. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  40. LIGO/Virgo S190814bv: DESGW photometry of AT2019npv
  41. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  42. LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
  43. GRB 190613B: GROND Detection of the Optical/NIR Afterglow
  44. LIGO/Virgo S190425z: GROND observations of AT2019ebq/PS19qp
  45. LIGO/Virgo S190408an: GROND Observations of MASTER OT J154209.55-431742.2
  46. GRB 190129B: Swift/UVOT Upper Limits
  47. GRB 190129B: ePESSTO NTT optical observations
  48. GRB 190129B: AstroSat CZTI detection
  49. GRB 190129B: MASTER Global Robotic Net optical observation
  50. GRB 190129B: GROND possible host candidate
  51. GRB 190114A: Swift/UVOT Observations
  52. GRB 190114C: AGILE/MCAL detection
  53. GRB 190114C: X-shooter observations of a highly extinguished afterglow
  54. GRB 190114C: Fermi GBM detection
  55. GRB 190114C: GROND detection of the afterglow
  56. GRB 190114A: GROND detection of the afterglow
  57. GRB 181203A: GROND detection of the afterglow
  58. GRB 181201A: Continued GROND observations show that afterglow is still bright
  59. GRB 181201A: GROND detection of the afterglow and redshift upper limit of z < 3
  60. GROND observations of GRB181110A
  61. GRB 181022A: GROND upper limits
  62. GROND afterglow detection of GRB 181010A
  63. GRB 180809B: GROND Detection of the NIR Afterglow
  64. GRB 180624A: GROND observations
  65. GRB 180620B: Swift/UVOT Detection
  66. GROND observations of GRB 180620B
  67. GROND observations of GRB 180620A
  68. GRB 180613A GROND observations: correction
  69. GRB 180613A GROND observations
  70. GRB 180512A: VLT/HAWK-I NIR Observations
  71. GRB 180512A: GROND upper limits
  72. GRB 180510B: GROND detection in all bands
  73. GRB 180418A: Further GROND observations
  74. GRB 180418A GROND observations
  75. GRB 180325A: GROND observations
  76. GRB 180325A: Global MASTER-Net OT prompt observations
  77. GROND observations of GRB 180316A
  78. GRB 180314A: MASTER-Net OT dtetction
  79. GRB180314A: GROND detection of the afterglow
  80. GRB 180205A: Further GROND Observations reveal Afterglow is still bright
  81. GRB 180205A: GROND detection of the NIR/optical afterglow
  82. GRB 171205A: GROND observations of the optical/NIR transient
  83. GRB 171027A: VLT optical upper limits
  84. GROND observations of GRB 171027A: correction
  85. GROND observations of GRB 171027A
  86. GRB170827A: Further GROND follow-up observations
  87. GROND observations of GRB170827A
  88. LIGO/Virgo G298048: GROND observations of candidate optical counterpart
  89. LIGO/Virgo G298048: NOT near-infrared observations of SSS17a
  90. LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
  91. GROND observations of GRB170604A
  92. GROND observations of GRB 170531B
  93. GRB 170428A: GTC spectroscopic redshift of candidate host galaxy
  94. GRB 170428A: TAROT La Silla observatory optical observations
  95. GRB 170428A: GROND detection of the afterglow
  96. LIGO/Virgo G277583: GROND follow up of ATLAS17cck
  97. GRB 170311A: Further GROND analysis
  98. GRB 170311A: GROND upper limits
  99. GRB170306A: SALT observations
  100. GRB 170306A: GROND afterglow detection

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