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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"

24581 results found.

  1. GRB 230614B: Swift/BAT-GUANO detection outside the coded FOV
  2. Fermi trigger No 708426906: Global MASTER-Net observations report
  3. GRB 230614B: Fermi GBM Final Real-time Localization
  4. GRB 230614A: Fermi GBM Final Real-time Localization
  5. GRB 230606A: LCOGT Optical Observations
  6. IceCube-Cascade 230610A: Upper limits from a search for additional neutrino events in IceCube
  7. LIGO/Virgo/KAGRA S230608as: Updated Sky localization
  8. LIGO/Virgo/KAGRA S230606d: Updated Sky localization
  9. LIGO/Virgo S230611be: Global MASTER-Net observations report
  10. LIGO/Virgo S230611l: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S230609u: Updated Sky localization
  12. LIGO/Virgo S230609u: Global MASTER-Net observations report
  13. LIGO/Virgo S230608aw: Global MASTER-Net observations report
  14. LIGO/Virgo/KAGRA S230609u: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo S230608as: Global MASTER-Net observations report
  16. LIGO/Virgo S230609a: Global MASTER-Net observations report
  17. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  18. LIGO/Virgo S230608q: Global MASTER-Net observations report
  19. ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit
  20. LIGO/Virgo/KAGRA S230608as: Identification of a GW compact binary merger candidate
  21. Fermi GRB 230603A: Global MASTER-Net observations report
  22. Fermi trigger No 707039690: Global MASTER-Net observations report
  23. GRB 230506B: Chandra localization of the X-ray afterglow
  24. ZTF and GIT Observations of the Candidate Optical Afterglow AT2023jxk
  25. GRB 230606A: Swift-BAT refined analysis
  26. GRB 230606A: Fermi GBM Observation
  27. LIGO/Virgo/KAGRA S230602ap: Zwicky Transient Facility observations
  28. GRB 230604A: GRBAlpha detection
  29. LIGO/Virgo S230606z: Global MASTER-Net observations report
  30. LIGO/Virgo S230606d: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S230606d: Identification of a GW compact binary merger candidate
  32. GRB 230606A: Swift detection of a burst
  33. Fermi-LAT gamma-ray observations of IceCube-230603A
  34. LIGO/Virgo/KAGRA S230605o: Updated Sky localization
  35. IceCube-230603A: Upper limits from a search for additional neutrino events in IceCube
  36. LIGO/Virgo/KAGRA S230601bf: Updated Sky localization
  37. Super-Kamiokande: Neutrino search for SN2023ixf
  38. LIGO/Virgo/KAGRA S230605o: Identification of a GW compact binary merger candidate
  39. LIGO/Virgo S230605o: Global MASTER-Net observations report
  40. LIGO/Virgo S230604z: Global MASTER-Net observations report
  41. IceCube-230603A - IceCube observation of a high-energy neutrino candidate track-like event
  42. GRB 230603A: Fermi GBM Final Real-time Localization
  43. LIGO/Virgo S230603aa: Global MASTER-Net observations report
  44. LIGO/Virgo S230602ap: Global MASTER-Net observations report
  45. LIGO/Virgo/KAGRA S230518h: Upper limits from a two-week IceCube neutrino search
  46. GRB 230521A: VZLUSAT-2 detection
  47. GRB 230522A: GRBAlpha and VZLUSAT-2 joint detection
  48. LIGO/Virgo S230601bf: Global MASTER-Net observations report
  49. LIGO/Virgo/KAGRA S230601bf: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo S230531f: Global MASTER-Net observations report
  51. GRB 230525A: CALET Gamma-Ray Burst Monitor detection
  52. LIGO/Virgo/KAGRA S230529ay: Zwicky Transient Facility observations
  53. LIGO/Virgo/KAGRA S230528a: Zwicky Transient Facility observations
  54. LIGO/Virgo/KAGRA S230527ch: Zwicky Transient Facility observations
  55. LIGO/Virgo/KAGRA S230529ay: Upper limits from CALET observations.
  56. LIGO/Virgo/KAGRA S230529ay: AstroSat CZTI non-detection and upper limits
  57. LIGO/Virgo S230529ay: Global MASTER-Net observations report
  58. LIGO/Virgo/KAGRA S230529ay: upper limits from AGILE/MCAL
  59. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  60. LIGO/Virgo/KAGRA S230529ay: Upper limits from Fermi-GBM Observations
  61. LIGO/Virgo/KAGRA S230529ay: Updated Sky localization and EM Bright Classification
  62. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  63. LIGO/Virgo/KAGRA S230529ay: Identification of a GW compact binary merger candidate
  64. LIGO/Virgo S230529p: Global MASTER-Net observations report
  65. GRB 230529A: Fermi GBM Final Real-time Localization
  66. Alert from the HAWC Burst Monitor HAWC-230527A
  67. LIGO/Virgo S230525a: Global MASTER-Net observations report
  68. LIGO/Virgo/KAGRA S230518h: Updated Sky localization
  69. LIGO/Virgo/KAGRA S230520ae: Updated Sky localization
  70. Fermi-LAT gamma-ray observations of IceCube-230524A
  71. LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
  72. GRB 230510A: Swift-BAT refined analysis
  73. GRB 230525A: Fermi GBM Detection
  74. LIGO/Virgo/KAGRA S230518h: TESS observations of the localization region
  75. GRB 230525A: Fermi GBM Final Localization
  76. IceCube-230524A: Upper limits from a search for additional neutrino events in IceCube
  77. GRB 230523B: GRBAlpha detection
  78. GRB 230524A: Fermi GBM Observation
  79. IceCube Alert 230524.47: Global MASTER-Net observations report
  80. LIGO/Virgo/KAGRA S230518h: No transient candidates in CALET observations
  81. LIGO/Virgo/KAGRA S230524x: Retraction of GW compact binary merger candidate
  82. IceCube-230524A - IceCube observation of a high-energy neutrino candidate track-like event
  83. Fermi trigger No 706610076: Global MASTER-Net observations report
  84. LIGO/Virgo S230524b: Global MASTER-Net observations report
  85. GRB 230524A: Fermi GBM Final Real-time Localization
  86. Fermi trigger No 706599831: Global MASTER-Net observations report
  87. Fermi trigger No 706536788: Global MASTER-Net observations report
  88. GRB 230523A: Swift/BAT-GUANO detection of a short hard burst
  89. LIGO/Virgo/KAGRA S230521k: Additional candidates from Zwicky Transient Facility
  90. GRB 230523A: Fermi GBM Final Real-time Localization
  91. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230523A
  92. LIGO/Virgo S230522n: Global MASTER-Net observations report
  93. LIGO/Virgo S230522a: Global MASTER-Net observations report
  94. LIGO/Virgo/KAGRA S230522n: Upper limits from IceCube neutrino search
  95. LIGO/Virgo/KAGRA S230522a: 2 counterpart neutrino candidates from IceCube neutrino searches
  96. LIGO/Virgo S230521k: Global MASTER-Net observations report
  97. LIGO/Virgo/KAGRA S230521k: Zwicky Transient Facility observations
  98. GRB 230518B: VZLUSAT-2 detection
  99. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  100. Fermi trigger No 706328428: Global MASTER-Net observations report

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