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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"

19687 results found.

  1. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  2. GRB 241228A: GROWTH-India telescope optical upper limit
  3. GRB 241228B: Swift ToO observations
  4. GRB 241228B: TRT optical counterpart confirmation
  5. GRB 241228A: Swift-XRT refined Analysis
  6. GRB 241228A: Swift/UVOT Upper Limits
  7. GRB 241228A: Enhanced Swift-XRT position
  8. GRB 241228A: Swift detection of a burst
  9. EP241223a: Mondy AZT-33IK optical observations
  10. GRB 241029A: LCO optical observation
  11. GRB 241223A: Swift-XRT observations
  12. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  13. GRB 241029A: AbAO AS-32 optical observations
  14. EP241223a
  15. EP241223a: EP-WXT detection of a fast X-ray transient
  16. GRB241113A: 7DT Optical upper limits
  17. GRB 241105A: JWST photometric observations of the host galaxy
  18. GRB 241223A: Swift ToO observations
  19. EP241217a: Liverpool Telescope optical upper limit
  20. EP241021a: VLA radio detection
  21. GRB 241218A: Mondy AZT-33IK optical upper limit
  22. EP241217a : Leavitt Observatory optical upper limit
  23. EP241217a: 1.6m Mephisto multi-band optical observations
  24. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  25. GRB 241218A: Swift/UVOT Upper Limits
  26. EP241217a: optical upper limit with the Liverpool Telescope
  27. GRB 241218A: NOT optical upper limits
  28. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  29. EP 241217a: NIR detection with P200/WIRC
  30. EP 241217a: Possible J-band detection with WINTER
  31. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  32. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  33. GRB 241217A / EP241217b: NOT optical upper limits
  34. GRB 241218A: REM optical upper limit
  35. GRB 241217A/EP241217b: REM optical/NIR upper limits
  36. EP241217a: REM optical/NIR upper limits
  37. GRB 241217a: Liverpool Telescope optical follow-up
  38. EP241217a: Liverpool Telescope optical follow-up
  39. EP241217a: NOT optical observations
  40. EP241217a: GROWTH-India Telescope optical observations
  41. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  42. EP241119a: 7DT Optical upper limits
  43. EP241217a: Xinglong optical follow-up observations
  44. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  45. GRB 241218A: LCOGT Optical Upper Limit
  46. GRB 241218A: Enhanced Swift-XRT position
  47. GRB 241217A: GMG Optical Upper Limit
  48. GRB 241218A: Swift detection of a burst
  49. GRB 241217A : SVOM/VT optical afterglow detection
  50. GRB 241217A: Swift-XRT afterglow detection
  51. GRB 241217A: LCO optical upper limit
  52. GRB 241217A: GRANDMA/TAROT optical upperlimits
  53. EP241217a: Swift-XRT Detection
  54. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  55. EP241217a: Kinder optical follow-up observations
  56. EP241217A: LCO optical observations
  57. EP241217a: Gemini-North detection of the likely optical counterpart
  58. EP241217a: EP detection of an X-ray transient
  59. EP241107a: VLA Radio Observation
  60. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  61. GRB 241215A: Mondy AZT-33IK optical observations
  62. GRB 241212A: Swift-XRT observations
  63. GRB 241215A: Nanshan/HMT optical upper limit
  64. GRB 241215A: Montarrenti Observatory optical upper limit
  65. GRB 241215A: GROWTH-India telescope optical upper limit
  66. GRB 241213B: Tiled Swift observations
  67. GRB 241213A: Swift/UVOT Upper Limits
  68. EP241208a: NOT optical upper limits
  69. GRB 241212A: Swift ToO observations
  70. GRB 241213A: LCOGT Optical Upper Limits
  71. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  72. EP241213a: EP detection of An X-ray Transient
  73. GRB 241213A: REM optical/NIR upper limits
  74. GRB 241213A: Enhanced Swift-XRT position
  75. GRB241212A: OHP/T193 optical observations
  76. GRB 241213A: SAO RAS optical upper limit
  77. GRB 241213A: Swift detection of a burst
  78. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  79. GRB 241209B: GRANDMA/TRT upper limit
  80. GRB 241212A: SVOM detection of a bright long burst
  81. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  82. GRB 241209D: REM optical/NIR upper limits
  83. GRB 241209B: Swift-XRT afterglow detection
  84. EP241208a: Optical upper limit with Kinder observations
  85. GRB 241209D: AstroSat CZTI detection
  86. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  87. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  88. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  89. GRB 241209D: COLIBRÍ detection of the afterglow
  90. GRB 241209A: COLIBRÍ Optical Upper Limit
  91. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  92. GRB 241209A: GRANDMA/TAROT upper limit
  93. GRB 241209B: Swift ToO observations
  94. GRB 241209A: REM optical/NIR observations
  95. GRB 241209D: Enhanced Swift-XRT position
  96. GRB 241209D: Swift detection of a burst
  97. GRB 241209A: Enhanced Swift-XRT position
  98. GRB 241114B: cubesat Avion detection
  99. GRB 241209A: VLT optical observations
  100. GRB 241209A: GOTO optical upper limits

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