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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"

45832 results found.

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

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