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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"

36790 results found.

  1. EP241202b: KAIT optical upper limit
  2. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  3. GRB 241204A: DDOTI Upper Limits on the Afterglow
  4. GRB 241204A: Fermi GBM Observation
  5. Fermi GRB 241204A: Global MASTER-Net observations report
  6. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  7. GRB 241128A : RAPAS follow-up observations
  8. GRB 241201A: GRBAlpha detection
  9. GRB 241204A: Fermi-LAT detection
  10. EP241202b: Upper limits from Fermi-GBM Observations
  11. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  12. GRB 241113B : RAPAS follow-up observation
  13. Konus-Wind detection of GRB 241130A
  14. IPN triangulation of GRB 241130A
  15. GRB 241130A: EIRSAT-1 GMOD Detection
  16. GRB 241128A: Swift/UVOT Upper Limits
  17. GRB 241130A: Fermi GBM Detection
  18. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  19. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  20. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  21. GRB241201B: Fermi GBM Final Localization
  22. GRB241201B: Fermi GBM Final Localization
  23. Fermi GRB 241201A: Global MASTER-Net observations report
  24. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  25. GRB 241130A: Fermi GBM Final Real-time Localization
  26. GRB 241130A: Fermi GBM Final Real-time Localization
  27. GRB 241201A: Fermi GBM Final Real-time Localization
  28. Fermi trigger No 754701230: Global MASTER-Net observations report
  29. IPN triangulation of GRB 241128B
  30. Konus-Wind detection of GRB 241114B
  31. GRB 241128A: AbAO optical upper limit
  32. SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
  33. GRB 241128C: SVOM/GRM observation
  34. GRB 241128B: SVOM/GRM observation
  35. GRB 241128A: Swift-BAT refined analysis
  36. GRB 241127A: Swift-BAT refined analysis
  37. GRB 241127A: PRIME near-infrared detection
  38. GRB 241128A: Mondy optical observations
  39. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  40. Swift GRB 241128A: Global MASTER-Net observations report
  41. Fermi-LAT gamma-ray observations of IceCube-241127A
  42. GRB 241128A: Swift-XRT refined Analysis
  43. GRB 241129A: Fermi GBM Final Real-time Localization
  44. GRB 241128A: Enhanced Swift-XRT position
  45. GRB 241128A: NOT optical observations
  46. GRB 241128A: LCO optical detection
  47. GRB 241128A: 1.5m OSN optical afterglow detection
  48. Fermi trigger No 754492985: Global MASTER-Net observations report
  49. GRB 241128A: Swift-XRT afterglow detection
  50. GRB 241128A: Swift detection of a burst
  51. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  52. GRB 241127A: Swift/UVOT Detection
  53. GRB 241127A: Swift-XRT refined Analysis
  54. GRB 241127A: SVOM/GRM observation
  55. GRB 241127A: Enhanced Swift-XRT position
  56. GRB 241127A: LCOGT (40-cm) optical counterpart detection
  57. GRB 241127A: Swift detection of a burst with an optical counterpart
  58. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  59. IceCube-241127A: IceCube observation of a high-energy neutrino candidate track-like event
  60. SVOM/GRM observation of GRB 241126B or a short burst from magnetar
  61. GRB 241126A: SVOM/GRM observation
  62. IPN triangulation of GRB 241114B
  63. GRB 241113B: EP-FXT afterglow detection
  64. Konus-Wind detection of GRB 241115D / EP 241115a
  65. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  66. GRB 241026A: radio detection with the VLA
  67. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  68. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  69. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  70. LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
  71. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  72. GRB 241120A: GRBAlpha detection
  73. GRB 241113B: SVOM/VT optical afterglow observations
  74. Konus-Wind detection of GRB 241117A
  75. GRB 241105A: ATCA radio detection
  76. IPN triangulation of GRB 241117A
  77. GRB 241026A: VIRT Optical Upper Limit
  78. GRB 241025A: VIRT Optical Upper Limit
  79. Konus-Wind detection of GRB 241120A
  80. GRB241120A: OHP/T193 optical observations
  81. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  82. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  83. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  84. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  85. GRB 241120A: Mondy and AbAO optical observations
  86. GRB 241113A: Possible ATCA Radio detection
  87. GRB 241120A: Fermi GBM Observation
  88. GRB 241114B: Insight-HXMT/HE detection
  89. GRB241120A: a long GRB detected by INTEGRAL
  90. GRB 241120A: Fermi GBM Final Real-time Localization
  91. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  92. GRB 241112B: Mephisto further optical observations
  93. GRB 241119A: Fermi GBM Final Real-time Localization
  94. GRB 241030A: J-band observations
  95. GRB 241115a: PRIME near-infrared upper limits
  96. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  97. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  98. GRB 241115B: Fermi GBM Observation
  99. Fermi GRB 241118A: Global MASTER-Net observations report
  100. GRB 241118A: Fermi GBM Final Real-time Localization

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