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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

4252 results found.

  1. GRB 241228B: SAO RAS optical observations
  2. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  3. IceCube-Cascade 241228A: Upper limits from a search for additional neutrino events in IceCube
  4. GRB 241229A: EP-FXT afterglow candidates
  5. Fermi Gamma-ray Burst Monitor trigger 757207662/241229978 (GRB 241229C) is not a GRB
  6. GRB 241229C: Fermi GBM Final Real-time Localization
  7. GRB 241229B: Fermi GBM Observation
  8. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  9. Swift GRB 241229B: Global MASTER-Net observations report
  10. GRB 241229A: GOTO optical upper limits
  11. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  12. GRB 241229B: Fermi GBM Final Real-time Localization
  13. GRB 241223A: GRBAlpha detection
  14. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  15. GRB 241029A: AbAO AS-32 optical observations
  16. Fermi trigger No 756678579: Global MASTER-Net observations report
  17. IceCube Alert 241224.30: Global MASTER-Net observations report
  18. Fermi Gamma-ray Burst Monitor trigger 756678579 / 241223854 is not a GRB
  19. Fermi trigger No 756447119: Global MASTER-Net observations report
  20. Fermi GRB 241221A: Global MASTER-Net observations report
  21. EP241217a: Liverpool Telescope optical upper limit
  22. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  23. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  24. EP241119a: 7DT Optical upper limits
  25. GRB 241213A: REM optical/NIR upper limits
  26. GRB 241207A: TSHAO Zeiss-1000 optical observations
  27. GRB 241129A: Fermi GBM Observation
  28. GRB 241209A: Swift-XRT refined Analysis
  29. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  30. EP241208a: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  32. Fermi GRB 241209E: Global MASTER-Net observations report
  33. Fermi GRB 241209A: Global MASTER-Net observations report
  34. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  35. Fermi GRB 241207A: Global MASTER-Net observations report
  36. GRB 241204A: DDOTI Upper Limits on the Afterglow
  37. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  38. EP241202b: Global MASTER-Net observations report
  39. GRB 241128A: AbAO optical upper limit
  40. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  41. GRB 241128A: Swift-BAT refined analysis
  42. GRB 241128A: Mondy optical observations
  43. Swift GRB 241128A: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  45. GRB 241129A: Fermi GBM Final Real-time Localization
  46. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  47. EP241126a: TRT optical counterpart detection
  48. LIGO/Virgo/KAGRA S241127aj: Identification of a GW compact binary merger candidate
  49. SVOM/GRM detection of a short burst from SGR 1830
  50. GECAM detection of a short burst from SGR 1830
  51. Konus-Wind detection of GRB 241115D / EP 241115a
  52. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  53. Fermi GRB 241118A: Global MASTER-Net observations report
  54. EP241113b: Global MASTER-Net observations report
  55. SVOM/GRM detection of a short burst from SGR 1E1841-045
  56. GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
  57. Fermi trigger No 752990530: Global MASTER-Net observations report
  58. Fermi trigger No 752878030: Global MASTER-Net observations report
  59. LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
  60. EP241107a: FTW Optical and NIR observations of the optical counterpart
  61. GRB 241030A: Mondy optical observations
  62. Fermi GRB 241105A: Global MASTER-Net observations report
  63. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  64. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  65. EP241021a: OHP/T193 further optical observations
  66. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  67. EP241103a: Global MASTER-Net observations report
  68. GRB 241029A: GRBAlpha detection
  69. GRB241030A: OHP/T193 optical observations
  70. GRB 241029A: LCO optical detection
  71. Fermi trigger No 752006065: Global MASTER-Net observations report
  72. EP241021a: Swift-UVOT detection
  73. EP241021a: Optical rebrightening observations with Mephisto
  74. GRB 241029A: GROWTH-India Telescope optical follow up
  75. GRB 241029A: SAO RAS optical observations
  76. GRB 241026A: SAO RAS optical observations
  77. EP241021a: SAO RAS observations of rebrightening
  78. GRB 241029A: Fermi GBM Observation
  79. GRB 241029A: AKO Optical Afterglow Detection
  80. GRB 241029A: GOTO optical afterglow detection
  81. GRB 241029A: MASTER early optical counterpart detection
  82. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  83. GRB 241029A: Mephisto observations
  84. GRB 241029A: TRT optical afterglow candidate detection
  85. GRB 241029A: SVOM/GRM observation
  86. Fermi trigger No 751861204: Global MASTER-Net observations report
  87. GRB 241029A: Fermi GBM Final Real-time Localization
  88. Fermi GRB 241026A: Global MASTER-Net observations report
  89. EP241021a: optical follow-up observations with Xinglong Observatory
  90. Fermi trigger No 751554401: Global MASTER-Net observations report
  91. EP241025a (GRB 241025A): EP observations update
  92. GRB 241018A: Mondy optical upper limit
  93. Fermi trigger No 750788395: Global MASTER-Net observations report
  94. GRB 241013B: Fermi GBM Observation
  95. GRB 241013A: Fermi GBM Observation
  96. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  97. GRB 241009A : Detection of a long duration GRB by SVOM/ECLAIRs
  98. LIGO/Virgo/KAGRA S241007bw: Identification of a GW compact binary merger candidate
  99. LIGO/Virgo/KAGRA S241006k: Identification of a GW compact binary merger candidate
  100. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT

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