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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"

4258 results found.

  1. LIGO/Virgo/KAGRA S250104v: Identification of a GW compact binary merger candidate
  2. Swift GRB 250103B: Global MASTER-Net observations report
  3. EP241231b and EP250101a: EP-WXT detection of two X-ray transients
  4. Fermi GRB 250101B: Global MASTER-Net observations report
  5. GRB 250101A: SAO RAS optical observations
  6. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  7. GRB 241228B: SAO RAS optical observations
  8. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  9. IceCube-Cascade 241228A: Upper limits from a search for additional neutrino events in IceCube
  10. GRB 241229A: EP-FXT afterglow candidates
  11. Fermi Gamma-ray Burst Monitor trigger 757207662/241229978 (GRB 241229C) is not a GRB
  12. GRB 241229C: Fermi GBM Final Real-time Localization
  13. GRB 241229B: Fermi GBM Observation
  14. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  15. Swift GRB 241229B: Global MASTER-Net observations report
  16. GRB 241229A: GOTO optical upper limits
  17. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  18. GRB 241229B: Fermi GBM Final Real-time Localization
  19. GRB 241223A: GRBAlpha detection
  20. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  21. GRB 241029A: AbAO AS-32 optical observations
  22. Fermi trigger No 756678579: Global MASTER-Net observations report
  23. IceCube Alert 241224.30: Global MASTER-Net observations report
  24. Fermi Gamma-ray Burst Monitor trigger 756678579 / 241223854 is not a GRB
  25. Fermi trigger No 756447119: Global MASTER-Net observations report
  26. Fermi GRB 241221A: Global MASTER-Net observations report
  27. EP241217a: Liverpool Telescope optical upper limit
  28. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  29. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  30. EP241119a: 7DT Optical upper limits
  31. GRB 241213A: REM optical/NIR upper limits
  32. GRB 241207A: TSHAO Zeiss-1000 optical observations
  33. GRB 241129A: Fermi GBM Observation
  34. GRB 241209A: Swift-XRT refined Analysis
  35. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  36. EP241208a: Global MASTER-Net observations report
  37. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  38. Fermi GRB 241209E: Global MASTER-Net observations report
  39. Fermi GRB 241209A: Global MASTER-Net observations report
  40. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  41. Fermi GRB 241207A: Global MASTER-Net observations report
  42. GRB 241204A: DDOTI Upper Limits on the Afterglow
  43. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  44. EP241202b: Global MASTER-Net observations report
  45. GRB 241128A: AbAO optical upper limit
  46. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  47. GRB 241128A: Swift-BAT refined analysis
  48. GRB 241128A: Mondy optical observations
  49. Swift GRB 241128A: Global MASTER-Net observations report
  50. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  51. GRB 241129A: Fermi GBM Final Real-time Localization
  52. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  53. EP241126a: TRT optical counterpart detection
  54. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  55. SVOM/GRM detection of a short burst from SGR 1830
  56. GECAM detection of a short burst from SGR 1830
  57. Konus-Wind detection of GRB 241115D / EP 241115a
  58. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  59. Fermi GRB 241118A: Global MASTER-Net observations report
  60. EP241113b: Global MASTER-Net observations report
  61. SVOM/GRM detection of a short burst from SGR 1E1841-045
  62. GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
  63. Fermi trigger No 752990530: Global MASTER-Net observations report
  64. Fermi trigger No 752878030: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
  66. EP241107a: FTW Optical and NIR observations of the optical counterpart
  67. GRB 241030A: Mondy optical observations
  68. Fermi GRB 241105A: Global MASTER-Net observations report
  69. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  70. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  71. EP241021a: OHP/T193 further optical observations
  72. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  73. EP241103a: Global MASTER-Net observations report
  74. GRB 241029A: GRBAlpha detection
  75. GRB241030A: OHP/T193 optical observations
  76. GRB 241029A: LCO optical detection
  77. Fermi trigger No 752006065: Global MASTER-Net observations report
  78. EP241021a: Swift-UVOT detection
  79. EP241021a: Optical rebrightening observations with Mephisto
  80. GRB 241029A: GROWTH-India Telescope optical follow up
  81. GRB 241029A: SAO RAS optical observations
  82. GRB 241026A: SAO RAS optical observations
  83. EP241021a: SAO RAS observations of rebrightening
  84. GRB 241029A: Fermi GBM Observation
  85. GRB 241029A: AKO Optical Afterglow Detection
  86. GRB 241029A: GOTO optical afterglow detection
  87. GRB 241029A: MASTER early optical counterpart detection
  88. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  89. GRB 241029A: Mephisto observations
  90. GRB 241029A: TRT optical afterglow candidate detection
  91. GRB 241029A: SVOM/GRM observation
  92. Fermi trigger No 751861204: Global MASTER-Net observations report
  93. GRB 241029A: Fermi GBM Final Real-time Localization
  94. Fermi GRB 241026A: Global MASTER-Net observations report
  95. EP241021a: optical follow-up observations with Xinglong Observatory
  96. Fermi trigger No 751554401: Global MASTER-Net observations report
  97. EP241025a (GRB 241025A): EP observations update
  98. GRB 241018A: Mondy optical upper limit
  99. Fermi trigger No 750788395: Global MASTER-Net observations report
  100. GRB 241013B: Fermi GBM Observation

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