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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

22195 results found.

  1. GRB 241229A: EP-FXT X-ray afterglow confirmation
  2. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  3. EP241217A: J band upper limit by SYSU 80cm telescope
  4. GRB 241228B: SAO RAS optical observations
  5. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  6. GRB 241229A: SAO RAS optical observations
  7. GRB 241229B: SVOM/VT optical candidate
  8. GRB 241229A: Swift-XRT observations
  9. EP240702a: 7DT Optical upper limits
  10. GRB 240606B: 7DT Optical upper limits
  11. Fermi trigger No 757231333: Global MASTER-Net observations report
  12. GRB241229B: UVOT upper limits
  13. GRB 241228B: D50 optical detection
  14. GRB 241228B: Fermi GBM Observation
  15. GRB 241228B: Swift-XRT afterglow detection
  16. GRB 241229A: Swift ToO observations
  17. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  18. GRB 241228A: Mondy optical afterglow observations
  19. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  20. Swift GRB 241229B: Global MASTER-Net observations report
  21. GRB 241229A: GOTO optical upper limits
  22. GRB 241228A: NOT optical upper limits
  23. GRB 241228B: LCO optical observation
  24. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  25. Fermi GRB 241228B: Global MASTER-Net observations report
  26. GRB241228B: GROWTH-India Telescope optical observations
  27. Swift GRB 241228A: Global MASTER-Net observations report
  28. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  29. GRB 241228B: GOTO24jmz optical follow-up observations
  30. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  31. GRB 241228B: Swift ToO observations
  32. GRB 241228B: TRT optical counterpart confirmation
  33. GRB 241228A: Swift/UVOT Upper Limits
  34. GRB 241228B: GOTO possible optical counterpart candidate
  35. GRB 241217A/EP241217b: continued SOAR observations
  36. Fermi GRB 241226A: Global MASTER-Net observations report
  37. EP241223a: Mondy AZT-33IK optical observations
  38. GRB 241029A: LCO optical observation
  39. GRB 241223A: Swift-XRT observations
  40. GRB 241029A: AbAO AS-32 optical observations
  41. Fermi trigger No 756678579: Global MASTER-Net observations report
  42. IceCube Alert 241224.30: Global MASTER-Net observations report
  43. EP241223a: Global MASTER-Net observations report
  44. EP241223a: EP-WXT detection of a fast X-ray transient
  45. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  46. GRB241113A: 7DT Optical upper limits
  47. Fermi GRB 241223A: Global MASTER-Net observations report
  48. GRB 241223A: GOTO optical observations summary
  49. GRB 241105A: JWST photometric observations of the host galaxy
  50. GRB 241223A: Swift ToO observations
  51. EP241217a: e-MERLIN radio observations
  52. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  53. Fermi trigger No 756447119: Global MASTER-Net observations report
  54. Fermi GRB 241221A: Global MASTER-Net observations report
  55. EP241021a: VLA radio detection
  56. GRB 241218A: Mondy AZT-33IK optical upper limit
  57. EP241217a : Leavitt Observatory optical upper limit
  58. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  59. EP241217a: 1.6m Mephisto multi-band optical observations
  60. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  61. GRB 241218A: Swift/UVOT Upper Limits
  62. GRB 241218A: NOT optical upper limits
  63. EP 241217a: NIR detection with P200/WIRC
  64. EP 241217a: Possible J-band detection with WINTER
  65. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  66. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  67. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  68. GRB 241217A / EP241217b: NOT optical upper limits
  69. GRB 241218A: REM optical upper limit
  70. GRB 241217A/EP241217b: REM optical/NIR upper limits
  71. EP241217a: REM optical/NIR upper limits
  72. EP241217a: Liverpool Telescope optical follow-up
  73. EP241217a: NOT optical observations
  74. EP241217a: GROWTH-India Telescope optical observations
  75. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  76. EP241119a: 7DT Optical upper limits
  77. EP241217b: Global MASTER-Net observations report
  78. GRB 241209A: ATCA radio follow-up observations
  79. EP241217a: Xinglong optical follow-up observations
  80. EP241217a: Global MASTER-Net observations report
  81. GRB 241217A : SVOM/VT optical afterglow detection
  82. GRB 241217A: Swift-XRT afterglow detection
  83. GRB 241217A: GRANDMA/TAROT optical upperlimits
  84. EP241217a: Swift-XRT Detection
  85. EP241217A: Non-detection from Fermi-GBM Observations
  86. EP241217a: Gemini-North spectroscopic redshift z = 4.59
  87. EP241217a: Kinder optical follow-up observations
  88. EP241217A: LCO optical observations
  89. EP241217a: Gemini-North detection of the likely optical counterpart
  90. EP241217a: EP detection of an X-ray transient
  91. EP241107a: VLA Radio Observation
  92. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  93. GRB 241215A: Mondy AZT-33IK optical observations
  94. GRB 241212A: Swift-XRT observations
  95. GRB 241215A: Nanshan/HMT optical upper limit
  96. GRB 241215A: Montarrenti Observatory optical upper limit
  97. Integral GRB241215.58: Global MASTER-Net observations report
  98. GRB 241213B: Swift-XRT observations
  99. GRB 241213A: SVOM/VT optical candidate
  100. GRB 241213B: Tiled Swift observations

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