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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

39219 results found.

  1. Swift GRB 240811A: Global MASTER-Net observations report
  2. GRB 240811A: Swift detection of a burst
  3. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  4. GRB 240810A: Fermi GBM Final Real-time Localization
  5. GRB 240809A: REM detection of the optical afterglow
  6. GRB 240809A: Bassano Bresciano Observatory optical observations
  7. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  8. GRB 240809A: Conclusive redshift from VLT
  9. Fermi-LAT gamma-ray observations of IceCube-240808A
  10. GRB 240809A: KAIT optical observations
  11. GRB 240808A: AstroSat CZTI detection
  12. GRB 240809A: GIT afterglow observations
  13. GRB 240809B: MAXI/GSC detection
  14. GRB 240809A: Swift/UVOT Detection
  15. GRB 240809A: Tentative redshift from NOT
  16. GRB 240809A: Swift-XRT refined Analysis
  17. IPN triangulation of GRB 240807A / EP 240807a
  18. X-ray Transient EP240807a: PRIME near-infrared upper limits
  19. Swift GRB 240809A: Global MASTER-Net observations report
  20. GRB 240809A: JinShan optical observations
  21. GRB 240809A: Enhanced Swift-XRT position
  22. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  23. GRB 240809A: SVOM/GRM observation
  24. GRB 240808A: SVOM/GRM observation
  25. GRB 240807A: SVOM/GRM observation
  26. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  27. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  28. GRB 240807B: AstroSat CZTI detection of a short burst
  29. IceCube Alert 240808.27: Global MASTER-Net observations report
  30. EP EP240807a: Global MASTER-Net observations report
  31. EP EP240806a: Global MASTER-Net observations report
  32. GRB 240801A: GRBAlpha detection
  33. GRB 240807B: Fermi GBM Final Localization
  34. GRB 240710B: VZLUSAT-2 detection
  35. GRB 240805A: ATCA Radio Upper Limits
  36. Fermi trigger No 744761058: Global MASTER-Net observations report
  37. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  38. EP-WXT trigger 01709018832: KAIT optical observations of the star flare
  39. EP240802a/GRB240802A: KAIT optical upper limit
  40. GRB 240720B: VZLUSAT-2 detection
  41. GRB 240710A: VZLUSAT-2 detection
  42. GRB 240807A: Fermi GBM Final Localization
  43. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  44. GRB 240805B: GIT optical upper limit
  45. EP240806a: KAIT optical observations
  46. GRB 240805B: Swift-BAT refined analysis
  47. GRB 240805A: Swift-BAT refined analysis
  48. Fermi trigger No 744629911: Global MASTER-Net observations report
  49. EP240804a (GRB 240804B): NOT optical observations
  50. EP240806a: LCOGT optical counterpart detection
  51. Konus-Wind detection of GRB 240802A (EP240802a)
  52. Improved IPN triangulation of GRB 240802A / EP 240802a
  53. Konus-Wind detection of GRB 240805A
  54. GRB 240805B Bassano Bresciano Observatory upper limit
  55. GRB240805A: Fermi GBM Observation
  56. GRB 240805B: JinShan optical afterglow detection
  57. GRB 240804B/EP240804a: Correction to the GRB name in GCN 37071
  58. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  59. Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
  60. Fermi Gamma-ray Burst Monitor trigger 240806402/744629911 is not a GRB
  61. GRB 240626B: VZLUSAT-2 detection
  62. GRB 240624B: VZLUSAT-2 detection
  63. GRB 240619C: VZLUSAT-2 detection
  64. EP 240806A: LCO optical observations
  65. GRB 240805B: Optical detection with 1.6m Mephisto
  66. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  67. GRB 240805B: Swift-XRT refined Analysis
  68. Fermi trigger No 744544656: Global MASTER-Net observations report
  69. GRB 240805B: Swift/UVOT Upper Limits
  70. GRB 240805A: Swift/UVOT Upper Limits
  71. GRB 240805B: BTA optical afterglow candidate
  72. GRB 240805A: SVOM/GRM observation
  73. GRB 240805B: Enhanced Swift-XRT position
  74. GRB 240805B: LCOGT Optical Upper Limits
  75. Swift GRB 240805B: Global MASTER-Net observations report
  76. GRB 240805B: JinShan optical upper limits
  77. Fermi GRB 240805A: Global MASTER-Net observations report
  78. Swift GRB 240805A: Global MASTER-Net observations report
  79. Fermi Gamma-ray Burst Monitor trigger 744558410/240805574 is not a GRB
  80. GRB 240805A: Swift-XRT refined Analysis
  81. EP240804a: GSP detects optical candidate counterpart
  82. GRB 240805B: Swift detection of a burst
  83. GRB 240805A: Fermi-LAT detection
  84. GRB 240805A: INTEGRAL spectral analysis
  85. EP240801a: Continued optical observations at ZTSh (CraO)
  86. EP240804a: LCOGT optical counterpart detection
  87. GRB 240805A: A long GRB detected by INTEGRAL
  88. EP240804a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  89. GRB 240805A: Swift detection of a burst
  90. GRB 240805A: Fermi GBM Final Real-time Localization
  91. Fermi GRB 240804A: Global MASTER-Net observations report
  92. EP240802a: Montarrenti Observatory optical upper limit
  93. GRB 240804A: Fermi GBM Final Real-time Localization
  94. Fermi trigger No 744459130: Global MASTER-Net observations report
  95. IPN triangulation of GRB 240802A / EP 240802a
  96. Fermi Gamma-ray Burst Monitor trigger 744459130/240804425 is not a GRB
  97. EP240802A: Bassano Bresciano Observatory upper limit
  98. GRB 240802A: SVOM/GRM observation
  99. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  100. Fermi trigger No 744278264: Global MASTER-Net observations report

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