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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"

45719 results found.

  1. EP240708a: GSP optical upper limit
  2. GRB 240712A: Swift detection of a burst
  3. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  4. GRB 240711A: Fermi GBM Final Real-time Localization
  5. Fermi trigger No 742405878: Global MASTER-Net observations report
  6. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  7. Fermi trigger No 742317942: Global MASTER-Net observations report
  8. EP240708a: KAIT optical upper limit
  9. Fermi GRB 240710A: Global MASTER-Net observations report
  10. GRB 240710A: Fermi GBM Final Real-time Localization
  11. EP240708a: NOT optical observations
  12. EP240708a: SVOM/C-GFT optical upper limit
  13. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  14. EP240708a: Optical upper limits with Kinder observations
  15. EP240708a: EP-WXT detection of a fast X-ray transient
  16. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  17. EP240703b: GSP optical upper limit
  18. Fermi Gamma-ray Burst Monitor trigger 741911057/240705933 is not a GRB
  19. GRB 240705A: Fermi GBM Final Real-time Localization
  20. EP240703b: TRT optical upper limits
  21. EP240703a: TRT further optical observation
  22. EP240702a: TRT optical upper limits
  23. Konus-Wind detection of GRB 240627A
  24. IPN triangulation of GRB 240628B (short)
  25. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  26. EP240703a and EP240703b: Swift/XRT upper limits
  27. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  28. EP240703a: KAIT optical upper limit
  29. EP240703a: BTA observations
  30. EP240703c: Kinder optical follow-up and Swift XRT observations
  31. EP240703a: BOOTES-3 optical upper limit
  32. EP240703a: Liverpool Telescope optical follow-up observations
  33. EP240703a/GRB 240703A: TRT optical candidate likely not real
  34. EP240703a: Kinder optical follow-up observations
  35. EP240703c: EP-WXT detection of an X-ray transient
  36. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  37. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  38. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  39. IPN triangulation of GRB 240627A
  40. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  41. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  42. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  43. EP240703b: EP-WXT detection of a fast X-ray transient
  44. Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
  45. EP240702a: Swift/XRT upper limit
  46. EP240703a: EP-WXT detection of a fast X-ray transient
  47. EP240702a: GSP optical upper limit
  48. The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
  49. GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
  50. Fermi GRB 240702A: Global MASTER-Net observations report
  51. GRB 240702A: Fermi GBM Final Real-time Localization
  52. EP240702a: EP-WXT detection of a fast X-ray transient
  53. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  54. Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
  55. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  56. Fermi trigger No 741448122: Global MASTER-Net observations report
  57. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  58. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  59. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  60. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  61. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  62. Fermi trigger No 741356809: Global MASTER-Net observations report
  63. Fermi GRB 240629A: Global MASTER-Net observations report
  64. Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
  65. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  66. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  67. GRB 240629A: Fermi GBM Final Real-time Localization
  68. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  69. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  70. Fermi trigger No 741296200: Global MASTER-Net observations report
  71. Fermi trigger No 741251380: Global MASTER-Net observations report
  72. IPN triangulation of GRB 240619C
  73. IceCube-Cascade 240626A: Upper limits from a search for additional neutrino events in IceCube
  74. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  75. GRB 240627A: NuSTAR Detection of the long GRB
  76. GRB 240615A: SAI CMO J- band observations
  77. GRB 240627A: AstroSat CZTI detection
  78. Fermi trigger No 741211696: Global MASTER-Net observations report
  79. EP240626a: Montarrenti Observatory optical upper limit
  80. EP240626a: KAIT optical upper limit
  81. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  82. EP240625a: GRANDMA Optical Upper Limits
  83. EP240626a: EP-FXT detection of the X-ray emission
  84. GRB 240624A: Swift-BAT refined analysis
  85. Konus-Wind detection of GRB 240619A
  86. EP240626a: BOOTES-7 optical upper limit
  87. EP240626a: EP-WXT detection of a fast X-ray transient
  88. Fermi GRB 240625B: Global MASTER-Net observations report
  89. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  90. GRB 240625B: Fermi GBM Final Real-time Localization
  91. GRB 240625A: Fermi GBM Observation
  92. EP240625a: NOT optical counterpart candidate
  93. EP240625a: EP-FXT detection of the X-ray emission
  94. GRB 240624B: GRBAlpha detection
  95. GRB 240625A: Fermi GBM Final Real-time Localization
  96. EP240625a: EP-WXT detection of a fast X-ray transient
  97. GRB240624A: Fermi GBM Observation
  98. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  99. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  100. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO

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