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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"

36353 results found.

  1. GRB 241108A: Swift-XRT observations
  2. EP241107A: MASTER optical observations of xray transient
  3. EP241107a: KAIT optical observations
  4. GRB 241108A: Swift ToO observations
  5. GRB 241030A: TESS observations
  6. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  7. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  8. GRB 241025A: radio detection with the VLA
  9. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  10. GRB 241107A: SVOM/GRM detection of a short burst
  11. GRB 241105A: EP-FXT follow-up observations
  12. GRB 241105A: SVOM/GRM observation
  13. GRB 241105a: PRIME near-infrared upper limits
  14. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  15. GRB 241025A: LBT optical observations
  16. GRB241105A: Gemini-South Optical Afterglow Detection
  17. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  18. GRB 241105A: Swift/UVOT Detection
  19. EP241101a: CrAO ZTSH optical observations
  20. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  21. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  22. GRB 241105A: BOOTES-7 optical detection
  23. GRB 241030A: Mondy optical observations
  24. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  25. Konus-Wind detection of GRB 241105A (short with extended emission)
  26. Konus-Wind detection of GRB 241021A
  27. GRB 241105A: SVOM/VT optical afterglow observations
  28. GRB 241105A: Swift-XRT afterglow detection
  29. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  30. GRB 241104A: Swift-XRT observations
  31. GRB 240511A: LCO upper limits
  32. GRB 241104A: Fermi GBM Observation
  33. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  34. GRB 241105A: Swift ToO observations
  35. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  36. GRB 241104A: Swift ToO observations
  37. GRB 241104A: NOT optical non-detection
  38. GRB 241105A: GOTO tentative optical counterpart candidate
  39. Fermi GRB 241105A: Global MASTER-Net observations report
  40. GRB 241104A: SVOM/VT optical candidate
  41. GRB 241105A: Fermi GBM Final Real-time Localization
  42. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  43. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  44. GRB 241104A: SVOM/GRM observation
  45. EP241104a: EP detection of GRB 241104A X-ray emission
  46. GRB 241010A: host galaxy redshift z = 0.977
  47. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  48. GRB 240821A: further radio observations with the VLA
  49. Fermi GRB 241104A: Global MASTER-Net observations report
  50. GRB 241104A: Fermi GBM Final Real-time Localization
  51. GRB 241030A: GRBAlpha detection
  52. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  53. GRB 241030A: Rapid release of TESS data.
  54. GRB 241029A: GRBAlpha detection
  55. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  56. Swift GRB 241101A: Global MASTER-Net observations report
  57. GRB 241101A: FRAM-ORM optical limit
  58. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  59. EP241021a: Upper limit from Konus-Wind observations
  60. GRB 241101A: Swift-BAT refined analysis
  61. GRB 241030A: further SAO RAS optical observations
  62. GRB 241030A: Optical Observations via Virtual Telescope Project
  63. GRB 241030B: Swift-XRT refined Analysis
  64. GRB 241026A: SAO RAS optical observations
  65. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  66. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  67. GRB 241101A: Swift detection of a burst
  68. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  69. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  70. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  71. GRB 241030B: Montarrenti Observatory optical upper limit
  72. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  73. GRB 241030A: SAO RAS optical observations
  74. GRB 241030A: Fermi GBM Observation
  75. GRB 241030B : GIT optical upper limits
  76. GRB 241030B: LCOGT Optical Upper Limits
  77. GRB 241030B: Swift-BAT refined analysis
  78. GRB 241030A: Swift-BAT refined analysis
  79. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  80. GRB 241030B: Swift/UVOT Detection
  81. GRB 241029A: LCO optical detection
  82. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  83. GRB 241030B: SVOM/GRM observation
  84. GRB 241030B : MITSuME Akeno optical upper limits
  85. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  86. GRB 241030B: SVOM/VT optical afterglow observations
  87. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  88. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  89. GRB241030B: Fermi GBM Observation
  90. GRB 241030B: BTA observations
  91. GRB 241029A: SVOM/VT optical afterglow observations
  92. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  93. GRB 241030B: Enhanced Swift-XRT position
  94. GRB 241030B: optical observations from the INAF Asiago Observatory
  95. GRB241030B: GRANDMA/TAROT Upper Limit
  96. GRB 241030A: Swift-XRT refined Analysis
  97. GRB 241030B: SAO RAS optical observations
  98. GRB 241030B: AKO Optical Afterglow Detection
  99. GRB 241030B: Nanshan/HMT optical afterglow detection
  100. GRB 241030B: SVOM/ECLAIRs detection of a burst

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