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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"

20520 results found.

  1. GRB 241105A: JWST photometric observations of the host galaxy
  2. Fermi GRB 241221A: Global MASTER-Net observations report
  3. EP241217a: Liverpool Telescope optical upper limit
  4. EP241021a: VLA radio detection
  5. GRB 241218A: Mondy AZT-33IK optical upper limit
  6. EP241217a : Leavitt Observatory optical upper limit
  7. EP241217a: 1.6m Mephisto multi-band optical observations
  8. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  9. GRB 241218A: Swift/UVOT Upper Limits
  10. EP241217a: optical upper limit with the Liverpool Telescope
  11. Konus-Wind detection of GRB 241204A (short/hard)
  12. GRB 241218A: NOT optical upper limits
  13. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  14. EP 241217a: NIR detection with P200/WIRC
  15. EP 241217a: Possible J-band detection with WINTER
  16. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  17. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  18. GRB 241217A / EP241217b: NOT optical upper limits
  19. GRB 241218A: REM optical upper limit
  20. GRB 241217A/EP241217b: REM optical/NIR upper limits
  21. EP241217a: REM optical/NIR upper limits
  22. GRB 241217a: Liverpool Telescope optical follow-up
  23. EP241217a: Liverpool Telescope optical follow-up
  24. GRB 241218A: Swift-XRT refined Analysis
  25. EP241217a: NOT optical observations
  26. EP241217a: GROWTH-India Telescope optical observations
  27. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  28. EP241119a: 7DT Optical upper limits
  29. EP241217a: Xinglong optical follow-up observations
  30. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  31. GRB 241218A: LCOGT Optical Upper Limit
  32. GRB 241218A: Enhanced Swift-XRT position
  33. GRB 241217A: GMG Optical Upper Limit
  34. GRB 241218A: Swift detection of a burst
  35. GRB 241217A : SVOM/VT optical afterglow detection
  36. GRB 241217A: Swift-XRT afterglow detection
  37. GRB 241217A: LCO optical upper limit
  38. GRB 241217A: GRANDMA/TAROT optical upperlimits
  39. EP241217a: Swift-XRT Detection
  40. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  41. EP241217a: Kinder optical follow-up observations
  42. EP241217A: LCO optical observations
  43. EP241217a: Gemini-North detection of the likely optical counterpart
  44. EP241217a: EP detection of an X-ray transient
  45. The EP-WXT trigger 01709129023 is likely a flaring star
  46. EP241107a: VLA Radio Observation
  47. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  48. GRB 241215A: Mondy AZT-33IK optical observations
  49. GRB 241212A: Swift-XRT observations
  50. GRB 241215A: Nanshan/HMT optical upper limit
  51. GRB 241215A: Montarrenti Observatory optical upper limit
  52. GRB 241215A: GROWTH-India telescope optical upper limit
  53. The EP-WXT trigger 01709128921 is likely a flaring star
  54. GRB 241213A: Swift/UVOT Upper Limits
  55. EP241208a: NOT optical upper limits
  56. GRB 241213A: LCOGT Optical Upper Limits
  57. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  58. EP241213a: EP detection of An X-ray Transient
  59. GRB 241213A: REM optical/NIR upper limits
  60. GRB 241213A: Enhanced Swift-XRT position
  61. GRB241212A: OHP/T193 optical observations
  62. GRB 241213A: SAO RAS optical upper limit
  63. GRB 241213A: Swift detection of a burst
  64. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  65. GRB 241209B: GRANDMA/TRT upper limit
  66. GRB 241207A: TSHAO Zeiss-1000 optical observations
  67. GRB 241212A: SVOM detection of a bright long burst
  68. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  69. GRB 241209D: REM optical/NIR upper limits
  70. GRB 241209B: Swift-XRT afterglow detection
  71. GRB 241209C: Fermi GBM Observation
  72. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  73. EP241208a: Optical upper limit with Kinder observations
  74. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  75. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  76. GRB 241209D: Fermi GBM Observation
  77. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  78. GRB 241209D: COLIBRÍ detection of the afterglow
  79. GRB 241209A: COLIBRÍ Optical Upper Limit
  80. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  81. GRB 241209A: GRANDMA/TAROT upper limit
  82. GRB 241209A: REM optical/NIR observations
  83. GRB 241209D: Enhanced Swift-XRT position
  84. GRB 241209D: Swift detection of a burst
  85. GRB 241209A: VLT/X-shooter spectroscopy
  86. GRB 241209A: Enhanced Swift-XRT position
  87. GRB 241209A: VLT optical observations
  88. GRB 241209A: GOTO optical upper limits
  89. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  90. EP241208a: EP detection of a fast X-ray transient
  91. GRB 241209A: Swift detection of a short burst
  92. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  93. GRB 241206A: DDOTI Upper Limit on the Afterglow
  94. EP241206a: BOOTES Global Network optical limits
  95. EP241206a: EP detection of a fast X-ray transient
  96. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  97. EP241201a: 1.6m Mephisto Optical Upper Limits
  98. GRB 241204A: COLIBRÍ Optical Upper Limit
  99. EP241202b: KAIT optical upper limit
  100. GRB 241204A: DDOTI Upper Limits on the Afterglow

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