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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"

28300 results found.

  1. GRB 240720B: AstroSat CZTI detection of a short burst
  2. GRB 240718A: Fermi GBM Observation
  3. GRB 240718A: SVOM/GRM observation
  4. GRB 240718A: BALROG localization (Fermi Trigger 742976945 / GRB 240718270)
  5. GRB 240712A: Swift-BAT refined analysis
  6. GRB 240716A: GECAM-B detection of a long burst
  7. IceCube-Cascade 240714A: X-ray follow-up observation with EP-FXT
  8. Fermi-LAT gamma-ray observations of IceCube-cascade-240714A
  9. GRB 240715A: Swift/UVOT observations of the XRT sources.
  10. GRB 240715A: Swift-XRT observations
  11. GRB240713A: Swift/UVOT Upper LImits
  12. EP240708a: X-ray follow-up observations with Swift/XRT
  13. LIGO/Virgo/KAGRA S240716b: Updated Sky localization
  14. GRB 240713A: Swift-XRT observations
  15. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  16. GRB 240712A: Swift-XRT refined Analysis
  17. GRB 240713A: LAST optical upper limit
  18. LIGO/Virgo/KAGRA S240716b: Identification of a GW compact binary merger candidate
  19. Fermi GRB 240715A: Global MASTER-Net observations report
  20. GRB 240713A: optical upper limits from the INAF Asiago Observatory
  21. GRB240715A: GRANDMA Optical Upper Limits
  22. GW s240422ed: Swift UVOT follow-up
  23. GRB 240712A: Swift/UVOT Upper Limits
  24. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  25. The EP-WXT source triggered on July 14th is likely a flaring star
  26. GRB 240713A: J-band upper limit from WINTER
  27. GRB 240713A: NOT optical upper limits on three EP/FXT candidates
  28. GRB 240713A: JinShan optical upper limits
  29. GRB 240713A: OHP/T120 optical upper limit
  30. GRB240713A: Optical upper limit with Kinder observations
  31. Fermi Sub-threshold Observation of GRB240713A
  32. GRB240713A : The first probable GRB Located on-Board SVOM by ECLAIRs
  33. EP240708a: GSP optical upper limit
  34. GRB 240712A: Swift detection of a burst
  35. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  36. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  37. Fermi GRB 240710A: Global MASTER-Net observations report
  38. EP240708a: NOT optical observations
  39. EP240708a: SVOM/C-GFT optical upper limit
  40. EP240708a: Optical upper limits with Kinder observations
  41. EP240708a: EP-WXT detection of a fast X-ray transient
  42. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  43. EP240703b: GSP optical upper limit
  44. EP240703b: TRT optical upper limits
  45. EP240703a: TRT further optical observation
  46. EP240702a: TRT optical upper limits
  47. IPN triangulation of GRB 240628B (short)
  48. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  49. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  50. EP240703a: BTA observations
  51. EP240703c: Kinder optical follow-up and Swift XRT observations
  52. EP240703a: Liverpool Telescope optical follow-up observations
  53. EP240703a: Kinder optical follow-up observations
  54. EP240703c: EP-WXT detection of an X-ray transient
  55. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  56. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  57. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  58. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  59. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  60. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  61. EP240703b: EP-WXT detection of a fast X-ray transient
  62. EP240703a: EP-WXT detection of a fast X-ray transient
  63. EP240702a: GSP optical upper limit
  64. GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
  65. EP240702a: EP-WXT detection of a fast X-ray transient
  66. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  67. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  68. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  69. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  70. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  71. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  72. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  73. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  74. IPN triangulation of GRB 240619C
  75. IceCube-Cascade 240626A: Upper limits from a search for additional neutrino events in IceCube
  76. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  77. GRB 240627A: NuSTAR Detection of the long GRB
  78. GRB 240615A: SAI CMO J- band observations
  79. GRB 240627A: AstroSat CZTI detection
  80. EP240626a: Montarrenti Observatory optical upper limit
  81. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  82. GRB 240624A: Swift-BAT refined analysis
  83. EP240626a: EP-WXT detection of a fast X-ray transient
  84. EP240625a: NOT optical counterpart candidate
  85. EP240625a: EP-FXT detection of the X-ray emission
  86. EP240625a: EP-WXT detection of a fast X-ray transient
  87. GRB240624A: Fermi GBM Observation
  88. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  89. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  90. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  91. GRB240615A: Gemini-North observations of the BAT and XRT positions
  92. GRB240615A: Gemini-North observations of the BAT and XRT positions
  93. GRB 240619A: detection of a radio counterpart with AMI-LA
  94. GRB 240624A: Swift detection of a burst
  95. GRB 240619A: J-band detection with WINTER
  96. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  97. EP240618a: NOT optical counterpart candidate
  98. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  99. GRB 240529A: JinShan optical observations
  100. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification

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