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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"

45793 results found.

  1. GRB 240414A: Swift/UVOT Detection
  2. LXT 240402A/GRB 240402B: Swift follow-up observations
  3. GRB 240414A: Mondy optical observations
  4. GRB 240414B: Fermi GBM Final Real-time Localization
  5. GRB 240414A: AKO Optical Upper Limit
  6. X-ray transient EP 240414a - GTC spectroscopic observations
  7. GRB 240415A: Prompt Swift-XRT observations
  8. GRB 240415A: Swift detection of a burst
  9. GRB 240415A: Fermi GBM Final Real-time Localization
  10. EP240413a: Upper limits from GECAM-B Observation
  11. EP 240414a: NOT optical counterpart confirmation
  12. GRB 240414A: Swift-XRT refined Analysis
  13. GRB240414A : J-band upper limits from WINTER
  14. GRB 240414A: Enhanced Swift-XRT position
  15. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  16. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  17. LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
  18. EP240413A: GOTO optical upper limits
  19. GRB 240414A: Skynet Optical Afterglow Observations
  20. Fermi trigger No 734754044: Global MASTER-Net observations report
  21. Swift GRB 240414A: Global MASTER-Net observations report
  22. EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
  23. IPN triangulation of GRB 240410A
  24. EP240413a: possible detection of the X-ray emission with EP-FXT after 14 hours
  25. EP240414a: EP-WXT detection of a fast X-ray transient
  26. IPN triangulation of GRB 240411A
  27. Fermi-LAT gamma-ray observations of IceCube-240412A
  28. GRB 240414A : MITSuME Akeno optical upper limits
  29. GRB 240414A: Redshift confirmation from GTC/OSIRIS+
  30. EP240413a: EP-WXT detection of a fast X-ray transient
  31. GRB 240414A : OHP/T193 redshift determination
  32. GRB 240414A : OHP/T193 optical counterpart detection
  33. GRB 240414A: Swift detection of a burst
  34. LIGO/Virgo/KAGRA S240413p: Updated Sky localization
  35. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  36. LIGO/Virgo/KAGRA S240413p: Zwicky Transient Facility observations
  37. EP240408a: GSP optical upper limit
  38. GRB 240411B: CrAO/ZTSh optical observations
  39. GRB 240411B: Kinder observations with Lulin observatory
  40. LIGO/Virgo/Kagra S240413p: NED Galaxies in the Localization Volume
  41. LIGO/Virgo/KAGRA S240413p: Identification of a GW compact binary merger candidate
  42. GRB 240411B: HiPERCAM/GTC observation
  43. IceCube Alert 240412.23: Global MASTER-Net observations report
  44. GRB 240411B: Swift-BAT refined analysis
  45. GRB 240411B: Swift-XRT refined Analysis
  46. IceCube-240412A - IceCube observation of a high-energy neutrino candidate track-like event
  47. GRB 240411B: 1.3m DFOT Optical observations
  48. GRB 240411A: GRBAlpha detection
  49. GRB 240411B: OHP/T193 optical observations
  50. GRB 240405A: Glowbug gamma-ray detection
  51. GRB 240411B: Enhanced Swift-XRT position
  52. GRB 240411B: LCO optical afterglow detection
  53. GRB 240411B: Swift detection of a burst
  54. GRB 240408B: GRBAlpha detection
  55. GRB 240411A: Fermi GBM Final Real-time Localization
  56. EP240408A: MASTER optical observations
  57. EP240408a: GROND detection of a candidate counterpart
  58. EP240408a: Upper limits from GECAM-B Observation
  59. EP240408a: Swift follow-up observation
  60. EP240408a: BOOTES-6/DPRT optical upper limit
  61. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  62. GRB 240405A: GRBAlpha detection
  63. EP240408a: EP-WXT detection of a fast X-ray transient
  64. Swift Trigger 1220736: detection of 4U 1543-62.
  65. GRB 240408B: AstroSat CZTI detection
  66. IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
  67. Fermi GRB 240408A: Global MASTER-Net observations report
  68. GRB 240408A: Fermi GBM Final Real-time Localization
  69. GRB 240407A: BALROG localization (Fermi Trigger 734144396 / GRB 240407042)
  70. GRB 240402C: CALET Gamma-Ray Burst Monitor detection
  71. Fermi GRB 240407A: Global MASTER-Net observations report
  72. GRB 240407A: Fermi GBM Final Real-time Localization
  73. Fermi-LAT gamma-ray observations of IceCube-240327B
  74. Fermi-LAT gamma-ray observations of IceCube-240327A
  75. LXT 240402A/GRB 240402B: rest-frame energetics from Konus-Wind observation
  76. Fermi GRB 240405B: Global MASTER-Net observations report
  77. GRB 240405B: Fermi GBM Final Real-time Localization
  78. GRB 240402C: Glowbug gamma-ray detection
  79. GRB 240405A: Fermi GBM Final Real-time Localization
  80. GRB 240402C: GRBAlpha detection
  81. GRB 240331A: GRBAlpha detection
  82. LXT 240402A/GRB 240402B: GECAM-C refined analysis
  83. Swift satellite resumes pointed science observations
  84. GRB 240403B: Glowbug gamma-ray detection
  85. GRB 240403A: Glowbug gamma-ray detection
  86. LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
  87. X-ray transient LXT 240402A: WFST optical upper limits​
  88. Konus-Wind detection of LXT 240402A/GRB 240402B
  89. GRB/FXT 240402B: Kinder optical counterpart candidate
  90. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  91. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  92. GRB 240403A: Fermi GBM Detection
  93. X-ray transient LXT240402A: AST3-3 optical upper limits
  94. LXT 240402A: EP-FXT detection of the X-ray afterglow
  95. Fermi GRB 240404A: Global MASTER-Net observations report
  96. GRB 240404A: Fermi GBM Final Real-time Localization
  97. LXT 240402A: MASTER optical observations with AGN in error-box
  98. GRB 240402B: GWAC-F50A optical upper limit
  99. GRB 240402B: GECAM-C detection
  100. X-ray transient LXT 240402A: LEIA detection

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