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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"

45827 results found.

  1. Swift GRB231215.41: Global MASTER-Net observations report
  2. GRB 231215A: Swift-XRT observations
  3. GRB 231215B: Fermi GBM Final Real-time Localization
  4. GRB 231215A: Swift detection of a burst
  5. GRB 231214A: Fermi-LAT detection
  6. GRB 231214A: Enhanced Swift-XRT position
  7. GRB 231214B: Swift/BAT-GUANO detection of a burst
  8. GRB231214A: BOOTES-6/DPRT optical upper limit
  9. Fermi trigger No 724278269: Global MASTER-Net observations report
  10. Fermi trigger No 724233240: Global MASTER-Net observations report
  11. Swift GRB231214.85: Global MASTER-Net observations report
  12. GRB 231214A: Swift detection of a burst
  13. GRB 231214A: Fermi GBM Final Real-time Localization
  14. GRB 231210B: REM optical/NIR upper limits
  15. IceCube-231211A: Upper limits from a search for additional neutrino events in IceCube
  16. LIGO/Virgo/KAGRA S231213ap: Updated Sky localization
  17. LIGO/Virgo/KAGRA S231213ap: Identification of a GW compact binary merger candidate
  18. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
  19. IceCube-231211A - IceCube observation of a high-energy neutrino candidate track-like event
  20. LIGO/Virgo/KAGRA S231206cc: Upper limits from Swift/BAT-GUANO
  21. LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
  22. GRB 231212A: GECAM-C detection of a likely short burst
  23. Fermi trigger No 724035412: Global MASTER-Net observations report
  24. GRB 231210B: MeerLICHT afterglow observations
  25. GRB 231210B: Swift-BAT refined analysis
  26. IceCube Alert 231211.03: Global MASTER-Net observations report
  27. IceCube-231202A: No candidates from the Zwicky Transient Facility
  28. GRB 231210B: Swift-XRT refined Analysis
  29. GRB 231210B: Enhanced Swift-XRT position
  30. GRB 231210B: VLT/X-shooter redshift
  31. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  32. Fermi trigger No 723906955: Global MASTER-Net observations report
  33. GRB 231210B: Swift detection of a burst with optical counterpart
  34. Swift GRB231210.90: Global MASTER-Net OT detection
  35. Swift GRB231210.90: Global MASTER-Net observations report
  36. IPN triangulation of GRB 231129C
  37. GRB 231210A: Fermi GBM Final Real-time Localization
  38. GRB 231208A: GRBAlpha detection
  39. GRB231205B: Swift/UVOT Upper Limits
  40. GRB 231208A: Glowbug gamma-ray detection
  41. GRB 231208A: AstroSat CZTI detection of a faint burst
  42. LIGO/Virgo/KAGRA S231206ca: Updated Sky localization
  43. IPN triangulation of GRB 231205A
  44. GRB 231205B: Swift-BAT refined analysis
  45. GRB 231205B: 1.3m DFOT Optical upper limit
  46. LIGO/Virgo/KAGRA S231206cc: Updated Sky localization and Source Classification
  47. GRB 231206A: joint location of multiple instruments by ETJASMIN
  48. GRB 231205B: optical upper limit in TSHAOand AbAO
  49. LIGO/Virgo/KAGRA S231206cc: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo/KAGRA S231206ca: Identification of a GW compact binary merger candidate
  51. GRB231115A: TURBO Pre-Burst Optical Upper Limits
  52. GRB 231205B: AGILE detection
  53. Fermi trigger No 723581802: Global MASTER-Net observations report
  54. GRB 231206B: Fermi GBM Final Real-time Localization
  55. GRB 231205B: Ondrejov D50 optical upper limit
  56. GRB 231205B: Swift-XRT refined Analysis
  57. Fermi-LAT gamma-ray observations of IceCube-231202A
  58. GRB 231205B: REM optical/NIR upper limits
  59. GRB 231129C: ASIM MXGS observation and localization
  60. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  61. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  62. GRB 231206A: GECAM-B detection of a short burst (correction)
  63. GRB 231205B : MITSuME Akeno optical upper limits
  64. GRB 231206A: GECAM-B detection of a short burst
  65. GRB 231205B: Zadko observatory - Gingin optical observations
  66. GRB 231205B: Gaoyazi/GOT optical upper limit
  67. GRB 231205B: Nanshan/HMT optical upper limit
  68. GRB 231205B: GECAM-B detection of a long burst
  69. GRB 231205B: LCOGT Optical Upper Limits
  70. GRB 231205A: DDOTI Upper Limits on the Afterglow
  71. LIGO/Virgo/KAGRA S231205c: One counterpart neutrino candidate event from an IceCube neutrino search
  72. GRB 231205B: Enhanced Swift-XRT position
  73. GRB 231204A: Glowbug gamma-ray detection
  74. Swift GRB231205.70: Global MASTER-Net observations report
  75. GRB 231204A: CALET Gamma-Ray Burst Monitor detection
  76. Fermi-LAT daily aperture light curve of T CrB now available
  77. GRB 231205B: AKO Optical Upper Limit
  78. GRB 231205B: Swift detection of a burst
  79. GRB 231205A: joint location of multiple instruments by ETJASMIN
  80. GRB 231204A: AstroSat CZTI detection
  81. GRB 231205A: GECAM-B detection of a short burst
  82. Fermi trigger No 723435916: Global MASTER-Net observations report
  83. Fermi trigger No 723326169: Global MASTER-Net observations report
  84. GRB 231205A: Fermi GBM Final Real-time Localization
  85. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  86. IceCube-231202A: Upper limits from a search for additional neutrino events in IceCube
  87. Fermi trigger No 723412808: Global MASTER-Net observations report
  88. GRB 231203A: Fermi GBM Observation
  89. GRB 231204A: Fermi GBM Final Real-time Localization
  90. GRB 231203A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  91. Konus-Wind detection of GRB 231129C
  92. IceCube-231202A - IceCube observation of a high-energy neutrino candidate track-like event
  93. Fermi trigger No 723279695: Global MASTER-Net observations report
  94. The Fermi GBM team reports the detection of a likely SHORT GRB
  95. GRB 231203A: Fermi GBM Final Real-time Localization
  96. GRB 231129C: Swift-XRT afterglow detection
  97. Fermi trigger No 723149952: Global MASTER-Net observations report
  98. GRB 231129C: PROMPT optical upper limits for the MAXI/GSC X-ray counterpart and the MASTER afterglow candidate
  99. GRB 231129A: VZLUSAT-2 detection
  100. GRB 231129B: Swift-XRT observations

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