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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"

36397 results found.

  1. GRB 241113A: Swift-XRT refined Analysis
  2. GRB 241113A: Swift/UVOT Detection
  3. GRB 241113A: REM detection of the optical/NIR afterglow
  4. Konus-Wind detection of GRB 241107A (short/hard)
  5. Fermi Gamma-ray Burst Monitor trigger 753166198/241113201 is not a GRB
  6. GRB 241113B: Swift ToO observations
  7. GRB 241113A: LCO optical observations
  8. GRB 241112B: GMG Optical Upper Limit
  9. GRB 241113A: Enhanced Swift-XRT position
  10. GRB241113A: LCOGT (40-cm) optical counterpart detection
  11. GRB 241113B : detection of a long GRB by SVOM/ECLAIRs
  12. GRB 241113A: MASTER010615.66-224018.2 optical counterpart detection
  13. GRB 241113A: Swift detection of a burst with an optical counterpart
  14. GRB 241105A: ATCA Radio Upper Limits
  15. GRB 241112B: AbAO optical upper limit
  16. GRB 241107A: GROWTH-India telescope optical upper limit
  17. Fermi GRB 241112A: Global MASTER-Net observations report
  18. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  19. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  20. GRB 241112B: Swift-XRT afterglow detection
  21. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  22. GRB 241112B: SVOM/GRM observation
  23. GRB 241112B: SVOM/VT afterglow detection
  24. Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB
  25. GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
  26. GRB 241112B: Mephisto optical upper limits
  27. GRB 241112B: GOTO optical upper limits
  28. GRB 241112B: Swift ToO observations
  29. GRB 241112B : detection of a long GRB by SVOM/ECLAIRs
  30. GRB 241107A: INTEGRAL IBIS localization
  31. GRB 241112A: Fermi GBM Final Real-time Localization
  32. GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
  33. IPN triangulation of GRB 241107A (short/hard)
  34. GRB 241107A: INTEGRAL/IBIS/PICsIT detection of a short burst
  35. GRB 241025C: VZLUSAT-2 detection
  36. GRB 241025A: VZLUSAT-2 detection
  37. GRB 241018A: cubesat Avion detection
  38. GRB 241111A: Fermi GBM Final Real-time Localization
  39. GRB 241030B: TESS detection of optical counterpart
  40. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  41. EP241107a: AbAO optical upper limit
  42. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  43. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  44. EP241109a: confirmation of a stellar flare by BOOTES-7
  45. GRB 241108A: Swift-XRT observations
  46. EP241107A: MASTER optical observations of xray transient
  47. EP241107a: KAIT optical observations
  48. GRB 241108A: Swift ToO observations
  49. GRB 241030A: TESS observations
  50. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  51. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  52. GRB 241025A: radio detection with the VLA
  53. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  54. GRB 241107A: SVOM/GRM detection of a short burst
  55. GRB 241105A: EP-FXT follow-up observations
  56. GRB 241105A: SVOM/GRM observation
  57. GRB 241105a: PRIME near-infrared upper limits
  58. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  59. GRB 241025A: LBT optical observations
  60. GRB241105A: Gemini-South Optical Afterglow Detection
  61. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  62. GRB 241105A: Swift/UVOT Detection
  63. EP241101a: CrAO ZTSH optical observations
  64. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  65. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  66. GRB 241105A: BOOTES-7 optical detection
  67. GRB 241030A: Mondy optical observations
  68. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  69. Konus-Wind detection of GRB 241105A (short with extended emission)
  70. Konus-Wind detection of GRB 241021A
  71. GRB 241105A: SVOM/VT optical afterglow observations
  72. GRB 241105A: Swift-XRT afterglow detection
  73. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  74. GRB 241104A: Swift-XRT observations
  75. GRB 240511A: LCO upper limits
  76. GRB 241104A: Fermi GBM Observation
  77. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  78. GRB 241105A: Swift ToO observations
  79. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  80. GRB 241104A: Swift ToO observations
  81. GRB 241104A: NOT optical non-detection
  82. GRB 241105A: GOTO tentative optical counterpart candidate
  83. Fermi GRB 241105A: Global MASTER-Net observations report
  84. GRB 241104A: SVOM/VT optical candidate
  85. GRB 241105A: Fermi GBM Final Real-time Localization
  86. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  87. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  88. GRB 241104A: SVOM/GRM observation
  89. EP241104a: EP detection of GRB 241104A X-ray emission
  90. GRB 241010A: host galaxy redshift z = 0.977
  91. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  92. GRB 240821A: further radio observations with the VLA
  93. Fermi GRB 241104A: Global MASTER-Net observations report
  94. GRB 241104A: Fermi GBM Final Real-time Localization
  95. GRB 241030A: GRBAlpha detection
  96. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  97. GRB 241030A: Rapid release of TESS data.
  98. GRB 241029A: GRBAlpha detection
  99. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  100. Swift GRB 241101A: Global MASTER-Net observations report

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