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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"

27226 results found.

  1. GRB 250103A: SVOM/C-GFT optical upper limit
  2. GRB 250101A: NUTTelA-TAO / BSTI Optical Limits
  3. IceCube Alert 250102.58: Global MASTER-Net observations report
  4. EP241231b: optical upper limit with the Liverpool Telescope
  5. GRB 250103A: SVOM detection of a long burst (duplicate submission)
  6. GRB 250103A: SVOM detection of a long burst
  7. EP250101a: Xinglong optical upper limit
  8. GRB 250102A: Fermi GBM Final Real-time Localization
  9. LIGO/Virgo/KAGRA S241230bd: Upper limits from Swift/BAT-GUANO
  10. GRB 250101A: Swift-BAT refined analysis
  11. GRB 250101A: LCO optical counterpart detection
  12. EP241231b and EP250101a: EP-WXT detection of two X-ray transients
  13. GRB 250101A NUTTelA-TAO / BSTI Early Measurements
  14. GRB 250101A: GMG spectroscopic redshift at z ~ 2.481
  15. GRB 250101A: Swift/UVOT Detection
  16. GRB 250101A: 1.6m Mephisto multi-band optical followup
  17. GRB 250101A: Swift-XRT refined Analysis
  18. Fermi Gamma-ray Burst Monitor trigger 757464861/250101954 is not a GRB
  19. GRB 250101A: Montarrenti Observatory optical observations and rebrightening
  20. GRB 250101A: LCOGT optical afterglow detection
  21. GRB 250101A: OASDG optical observations
  22. Fermi GRB 250101B: Global MASTER-Net observations report
  23. GRB 250101B: Fermi GBM Final Real-time Localization
  24. GRB 250101A: SAO RAS observations of optical brightening
  25. GRB 250101A: BOOTES-4/MET optical afterglow detection
  26. GRB 250101A: AKO Optical Afterglow Detection
  27. GRB 250101A: SVOM/C-GFT early optical observations
  28. LIGO/Virgo/KAGRA S250101k: Upper limits from Fermi-GBM Observations
  29. GRB 250101A: MASTER earlier OT observations with SOSS emission features
  30. GRB 250101A: Nanshan/HMT optical observations
  31. GRB 250101A : GIT optical detection
  32. GRB 250101A: GMG Optical Observation
  33. GRB 250101A: Swift detection of a burst with an optical counterpart
  34. Swift GRB250101.56: Global MASTER-Net observations report
  35. GRB 241217a/EP241217b: ATCA Radio Detection
  36. LIGO/Virgo/KAGRA S241231du: Coverage and upper limit from MAXI/GSC observations
  37. GRB 241229B: Continued CrAO ZTSh observations
  38. GRB 241229A: EP-FXT X-ray afterglow confirmation
  39. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  40. GRB 241229B: SVOM/GRM observation
  41. EP241217A: J band upper limit by SYSU 80cm telescope
  42. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  43. GRB 241229B: SVOM/VT optical candidate
  44. GRB 241229A: EP-FXT afterglow candidates
  45. Fermi trigger No 757231333: Global MASTER-Net observations report
  46. GRB 241229B: Swift-BAT refined analysis
  47. Fermi Gamma-ray Burst Monitor trigger 757207662/241229978 (GRB 241229C) is not a GRB
  48. GRB241229B: UVOT upper limits
  49. GRB 241229C: Fermi GBM Final Real-time Localization
  50. GRB 241228B: D50 optical detection
  51. GRB 241228B: Fermi GBM Observation
  52. GRB 241229B: Fermi GBM Observation
  53. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  54. GRB 241229B: Swift-XRT refined Analysis
  55. Swift GRB 241229B: Global MASTER-Net observations report
  56. GRB 241229A: GOTO optical upper limits
  57. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  58. GRB 241228A: NOT optical upper limits
  59. GRB 241228B: LCO optical observation
  60. GRB 241228A: Swift-BAT refined analysis
  61. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  62. GRB 241229B: Swift detection of a burst
  63. GRB 241229B: Fermi GBM Final Real-time Localization
  64. GRB 241229A: SVOM detection of a long burst
  65. Fermi GRB 241228B: Global MASTER-Net observations report
  66. GRB 241228A: Fermi GBM Observation
  67. GRB241228B: GROWTH-India Telescope optical observations
  68. Swift GRB 241228A: Global MASTER-Net observations report
  69. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  70. GRB 241228B: GOTO24jmz optical follow-up observations
  71. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  72. GRB 241228A: GROWTH-India telescope optical upper limit
  73. GRB 241228B: TRT optical counterpart confirmation
  74. GRB 241228A: Swift-XRT refined Analysis
  75. GRB 241228A: Swift/UVOT Upper Limits
  76. GRB 241228B: GOTO possible optical counterpart candidate
  77. GRB 241228B: Fermi GBM Final Real-time Localization
  78. GRB 241228A: Swift detection of a burst
  79. LIGO/Virgo/KAGRA S241225c: Two counterpart neutrino candidates from IceCube neutrino searches
  80. GRB 241223A: GRBAlpha detection
  81. Fermi GRB 241226A: Global MASTER-Net observations report
  82. GRB 241226A: Fermi GBM Final Real-time Localization
  83. EP241223a: Mondy AZT-33IK optical observations
  84. GRB 241029A: LCO optical observation
  85. GRB 241029A: AbAO AS-32 optical observations
  86. GRB 241223A: Fermi GBM Detection
  87. Fermi trigger No 756678579: Global MASTER-Net observations report
  88. EP241223a
  89. IceCube Alert 241224.30: Global MASTER-Net observations report
  90. GRB 241219A: SVOM/GRM observation
  91. EP241223a: Global MASTER-Net observations report
  92. EP241223a: EP-WXT detection of a fast X-ray transient
  93. Fermi Gamma-ray Burst Monitor trigger 756678579 / 241223854 is not a GRB
  94. Fermi GRB 241223A: Global MASTER-Net observations report
  95. GRB 241223A: GOTO optical observations summary
  96. GRB 241105A: JWST photometric observations of the host galaxy
  97. EP241217a: e-MERLIN radio observations
  98. GRB 241223A: BALROG localization (Fermi Trigger 756648531 / GRB 241223506)
  99. GRB 241223A: Fermi GBM Final Real-time Localization
  100. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations

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