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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"

22198 results found.

  1. GRB 231118A: MeerLICHT afterglow detection
  2. GRB 231117A: OHP/T120 optical observations
  3. Fermi trigger No 722039659: Global MASTER-Net observations report
  4. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  5. GRB 231117A: 10 GHz VLA detection
  6. GRB 231118A: LCOGT Optical Observations
  7. GRB 231118A: MASTER OT observation
  8. GRB 231118A: Continued Skynet Observations
  9. Swift GRB231118.72: Global MASTER-Net observations report
  10. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  11. GRB 231117A: Lowell Discovery Telescope Observations
  12. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  13. GRB 231117A: ATCA detection of a radio counterpart
  14. GRB 231117A: Keck spectroscopy of afterglow candidate
  15. GRB 231115A: Wendelstein Optical/Infrared Observations
  16. GRB 231115A: JinShan optical upper limits
  17. GRB 231117A: LT observations consistent with fading
  18. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  19. GRB 231117A: REM optical and NIR early-time observations
  20. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  21. Swift GRB 231117A: Global MASTER-Net observations report
  22. GRB 231117A: ATLAS non-detection of an optical counterpart
  23. GRB 231115A : OHP/T120 optical upper limit
  24. GRB 231115A: optical observations from INAF observatories
  25. GRB 231111A: Swift/UVOT Detection
  26. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  27. GRB 231115A: NuSTAR Follow-Up Observations
  28. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  29. GRB 231115A: Swift-XRT and Swift-UVOT observations
  30. Fermi GRB 231116A: Global MASTER-Net observations report
  31. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  32. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  33. GRB 231115A: archival Chandra X-ray observations
  34. GRB 231115A: Kinder observations with Lulin observatory
  35. GRB231115A: GRANDMA Observations
  36. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  37. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  38. GRB 231106A: TESS identification of candidate optical counterpart
  39. GRB 231115A: MASTER optical observations
  40. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  41. GRB 231115A: archival HST observations
  42. Integral GRB231115.65: Global MASTER-Net observations report
  43. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  44. GRB 231115A: Swift ToO observations
  45. Fermi GRB 231115A: Global MASTER-Net observations report
  46. GRB 231115A position consistent with M 82 galaxy
  47. LIGO/Virgo/KAGRA S231113bw: Zwicky Transient Facility observations
  48. Fermi GRB 231114A: Global MASTER-Net observations report
  49. LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
  50. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  51. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  52. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  53. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  54. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  55. GRB 231111A: Xinglong-2.16m optical observations
  56. GRB 231110A: Swift-UVOT Upper Limits
  57. GRB 231111A: Afterglow redshift from OSIRIS+/GTC
  58. GRB 231111A: TNG tentative redshift
  59. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  60. GRB 231111A: Leavitt Observatory optical observations
  61. GRB231111A: Optical follow-up observations with Mephisto
  62. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  63. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  64. GRB 231111A: Mondy optical observations
  65. GRB 231110A: SAO RAS optical observations
  66. GRB 231110A: Swift-XRT afterglow detection
  67. GRB231111A: YAHPT Observations
  68. GRB 231111A: MASTER OT earlier detection
  69. GRB 231111A: Nanshan/HMT optical observations
  70. Swift GRB231111.60: Global MASTER-Net observations report
  71. GRB231110A: WFST Observation and upper limits
  72. Swift GRB231110.89: Global MASTER-Net observations report
  73. IceCube-231103A: No candidates from the Zwicky Transient Facility
  74. Fermi trigger No 721204446: Global MASTER-Net observations report
  75. Fermi GRB 231108A: Global MASTER-Net observations report
  76. Fermi trigger No 721006392: Global MASTER-Net observations report
  77. LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
  78. Fermi GRB 231106A: Global MASTER-Net observations report
  79. GRB 231104A: Wendelstein Optical/Infrared Observations
  80. Fermi-LAT gamma-ray observations of IceCube-231103A
  81. GRB 231104A: NOT upper limit
  82. Fermi GRB 231103A: Global MASTER-Net observations report
  83. GRB 231104A: Swift/UVOT Upper Limits
  84. Swift GRB231104.07: Global MASTER-Net observations report
  85. IceCube Alert 231103.39: Global MASTER-Net observations report
  86. Fermi-LAT gamma-ray observations of IceCube-231027A
  87. LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report
  88. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  89. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  90. Fermi trigger No 720498201: Global MASTER-Net observations report
  91. Fermi trigger No 720415645: Global MASTER-Net observations report
  92. Fermi GRB 231030B: Global MASTER-Net observations report
  93. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  94. Fermi GRB 231030A: Global MASTER-Net observations report
  95. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  96. LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
  97. Fermi trigger No 720224759: Global MASTER-Net observations report
  98. Swift GRB 231028A: Global MASTER-Net observations report
  99. GRB 231028A: Swift detection of a burst
  100. IceCube Alert 231027.18: Global MASTER-Net observations report

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