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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"

21947 results found.

  1. GRB 241215A: GROWTH-India telescope optical upper limit
  2. Integral GRB241215.58: Global MASTER-Net observations report
  3. GRB 241213A: Swift/UVOT Upper Limits
  4. EP241208a: NOT optical upper limits
  5. GRB 241213A: LCOGT Optical Upper Limits
  6. EP241213a: EP detection of An X-ray Transient
  7. GRB 241213A: REM optical/NIR upper limits
  8. GRB 241213A: Enhanced Swift-XRT position
  9. GRB241212A: OHP/T193 optical observations
  10. GRB 241213A: SAO RAS optical upper limit
  11. GRB 241213A: Swift detection of a burst
  12. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  13. GRB 241209B: GRANDMA/TRT upper limit
  14. GRB 241212A: SVOM detection of a bright long burst
  15. GRB 241209B: GRBAlpha detection
  16. GRB 241206C: GRBAlpha detection
  17. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  18. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  19. GRB 241209D: REM optical/NIR upper limits
  20. GRB 241209B: Swift-XRT afterglow detection
  21. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  22. EP241208a: Optical upper limit with Kinder observations
  23. GRB 241209D: AstroSat CZTI detection
  24. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  25. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  26. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  27. GRB 241209D: COLIBRÍ detection of the afterglow
  28. GRB 241209A: COLIBRÍ Optical Upper Limit
  29. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  30. GRB 241209A: GRANDMA/TAROT upper limit
  31. GRB 241209B: BOOTES-5 optical upper limit
  32. LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
  33. GRB 241209A: REM optical/NIR observations
  34. GRB 241209D: Enhanced Swift-XRT position
  35. GRB 241209D: Swift detection of a burst
  36. GRB 241209A: Enhanced Swift-XRT position
  37. GRB 241114B: cubesat Avion detection
  38. GRB 241209A: VLT optical observations
  39. GRB 241209A: GOTO optical upper limits
  40. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  41. EP241208a: EP detection of a fast X-ray transient
  42. GRB 241209A: Swift detection of a short burst
  43. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  44. GRB 241206A: DDOTI Upper Limit on the Afterglow
  45. EP241206a: BOOTES Global Network optical limits
  46. EP241206a: EP detection of a fast X-ray transient
  47. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  48. GRB 241206B: SVOM/ECLAIRs detection of a long soft transient
  49. EP241201a: 1.6m Mephisto Optical Upper Limits
  50. GRB 241204A: COLIBRÍ Optical Upper Limit
  51. EP241202b: KAIT optical upper limit
  52. GRB 241204A: DDOTI Upper Limits on the Afterglow
  53. GRB 241201A: GRBAlpha detection
  54. GRB 241204A: Fermi-LAT detection
  55. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  56. EP241202b: Kinder optical counterpart candidate
  57. Konus-Wind detection of GRB 241130A
  58. EP241201a: BOOTES-5 optical upper limit
  59. EP241202b: EP detection of a fast X-ray transient
  60. EP241201a: NOT optical observations
  61. GRB 241128A: Swift/UVOT Upper Limits
  62. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  63. EP241201a: Kinder optical counterpart candidate
  64. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  65. EP241126a: 1.6m Mephisto Optical Upper Limits
  66. LIGO/Virgo/KAGRA S241201ac: Identification of a GW compact binary merger candidate
  67. Konus-Wind detection of GRB 241114B
  68. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  69. GRB 241128A: AbAO optical upper limit
  70. LIGO/Virgo/KAGRA S241130be: Identification of a GW compact binary merger candidate
  71. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  72. GRB 241127A: PRIME near-infrared detection
  73. GRB 241128A: Mondy optical observations
  74. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  75. Swift-XRT observations of IceCube -241127A
  76. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  77. GRB 241128A: Enhanced Swift-XRT position
  78. GRB 241128A: NOT optical observations
  79. GRB 241128A: LCO optical detection
  80. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  81. GRB 241128A: Swift-XRT afterglow detection
  82. GRB 241128A: Swift detection of a burst
  83. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  84. GRB 241127A: Swift/UVOT Detection
  85. GRB 241127A: Enhanced Swift-XRT position
  86. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  87. Swift GRB241127.91: Global MASTER-Net OT detection
  88. EP241126a: WFST Observations
  89. GRB 241127A: Swift detection of a burst with an optical counterpart
  90. Swift GRB241127.91: Global MASTER-Net OT detection
  91. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  92. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  93. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  94. EP241126a: Optical Upper limits with Kinder observations
  95. IPN triangulation of GRB 241114B
  96. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  97. EP241126a: GSP detects optical counterpart
  98. EP241126a: TRT optical counterpart detection
  99. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  100. EP241126a: EP detection of a fast X-ray transient

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