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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"

19720 results found.

  1. GRB240713A : The first probable GRB Located on-Board SVOM by ECLAIRs
  2. GRB 240712A: Swift detection of a burst
  3. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  4. EP240708a: NOT optical observations
  5. EP240708a: SVOM/C-GFT optical upper limit
  6. EP240708a: Optical upper limits with Kinder observations
  7. EP240708a: EP-WXT detection of a fast X-ray transient
  8. EP240703b: TRT optical upper limits
  9. EP240703a: TRT further optical observation
  10. EP240702a: TRT optical upper limits
  11. IPN triangulation of GRB 240628B (short)
  12. EP240703c: Kinder optical follow-up and Swift XRT observations
  13. EP240703a: Liverpool Telescope optical follow-up observations
  14. EP240703a: Kinder optical follow-up observations
  15. EP240703c: EP-WXT detection of an X-ray transient
  16. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  17. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  18. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  19. EP240703b: EP-WXT detection of a fast X-ray transient
  20. EP240702a: Swift/XRT upper limit
  21. EP240703a: EP-WXT detection of a fast X-ray transient
  22. EP240702a: EP-WXT detection of a fast X-ray transient
  23. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  24. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  25. IPN triangulation of GRB 240619C
  26. GRB 240615A: SAI CMO J- band observations
  27. GRB 240627A: AstroSat CZTI detection
  28. EP240626a: Montarrenti Observatory optical upper limit
  29. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  30. EP240626a: EP-WXT detection of a fast X-ray transient
  31. EP240625a: NOT optical counterpart candidate
  32. EP240625a: EP-WXT detection of a fast X-ray transient
  33. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  35. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  36. GRB240615A: Gemini-North observations of the BAT and XRT positions
  37. GRB240615A: Gemini-North observations of the BAT and XRT positions
  38. GRB 240619A: detection of a radio counterpart with AMI-LA
  39. GRB 240619A: J-band detection with WINTER
  40. EP240618a: NOT optical counterpart candidate
  41. GRB 240529A: JinShan optical observations
  42. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  43. X-ray transient EP240618a: Fermi/GBM non-detection
  44. GRB 240619A: Swift ToO observations
  45. GRB 240615A: NOT optical observations
  46. EP240618a: GRANDMA Optical Upper Limits
  47. GRB 240619C: AstroSat CZTI detection
  48. EP240618a: TRT optical upper limit
  49. EP240617a: STEP/T80S optical limits
  50. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  51. GRB240615A: 1.3m DFOT optical upper limit
  52. EP240617a: EP-WXT detection of a fast X-ray transient
  53. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  54. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  55. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  56. GRB 240615A: J-band upper limits from WINTER
  57. GRB 240615A: Swift ToO observations
  58. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  59. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  60. GRB 240529A: LBT optical detection and late temporal decay
  61. GRB 240529A : MITSuME Akeno optical afterglow detection
  62. Trigger 1236151: Swift detection of EXO 0748-676
  63. IPN triangulation of GRB 240607A
  64. GRB 240608A: Fermi GBM Final Real-time Localization
  65. Swift Trigger 1235109: consistent with noise and not astrophysical
  66. GRB 240529A: radio detection with AMI-LA
  67. GRB 240606B: Swift-XRT afterglow detection
  68. GRB 240606B: Swift ToO observations
  69. Swift Trigger 1235109: a possible GRB 240606A
  70. GRB 240529A: SAO RAS optical observations
  71. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  72. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  73. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  74. GRB 240529A: MASTER prompt OT detection
  75. GRB 240529A: continued SAO RAS optical observations
  76. The EP-WXT source triggered on June 1st is likely a flaring star
  77. GRB 240529A: further SAO RAS optical observations
  78. Swift Trigger 1232465 is not a GRB
  79. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  80. GRB 240529A: 1.3m DFOT Optical observations
  81. GRB 240531A: AstroSat CZTI detection of a short burst
  82. GRB 240529A : Mondy optical observations
  83. GRB 240529A: SAO RAS optical observations
  84. GRB 240529A: GROWTH-India optical follow-up
  85. GRB 240529A: T193/MISTRAL observations
  86. GRB 240529A: Redshift from GTC/OSIRIS+
  87. GRB 240529A: AKO Optical Afterglow Detection
  88. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  89. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  90. GRB 240529A: J-band detections with WINTER
  91. GRB 240529A: Skynet Optical Observations
  92. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  93. GRB 240529A: Swift/UVOT Detection
  94. GRB 240529A: NOT optical observations
  95. GRB 240527B: Swift-XRT afterglow detection
  96. GRB 240529A: Enhanced Swift-XRT position
  97. GRB 240529A: Swift detection of a burst with an optical counterpart
  98. GRB 240523A: Swift-XRT refined Analysis
  99. GRB 240523A: Enhanced Swift-XRT position
  100. GRB 240523A: Swift detection of a burst

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