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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

45716 results found.

  1. GRB 250127A: SVOM/VT upper limit
  2. GRB 250127B: Fermi GBM Final Real-time Localization
  3. IPN triangulation of GRB 250119C
  4. GRB 250127A: Swift ToO observations
  5. GRB 250127A: LCO optical upper limit
  6. GRB 241223A: cubesat Avion detection
  7. GRB 250127A: SVOM detection of a long burst
  8. GRB 250126A: CALET Gamma-Ray Burst Monitor detection
  9. EP250125A: Non-detection from Fermi-GBM Observations
  10. GRB 250126A: MAXI/GSC detection
  11. EP250108a / SN 2025kg: Refined Analysis of EP-WXT Detection
  12. GRB 250126A: BALROG localization (Fermi Trigger 759560335 / GRB 250126208)
  13. GRB 250126A: Fermi GBM Final Real-time Localization
  14. GECAM-A detection of a bright burst from SGR 1E1841-045
  15. GRB 250118A: Fermi GBM Observation
  16. EP250125a: Optical upper limit with Kinder observations
  17. EP250125a: REM optical counterpart detection
  18. GRB 250119C: Fermi GBM Observation
  19. EP250125a: Swift/XRT detection of a fading counterpart
  20. EP250125a: a new X-ray transient detected by Einstein Probe
  21. EP250125a: Gemini-South optical afterglow discovery and redshift z = 2.89
  22. The EP-WXT trigger 01709130758 is a false trigger
  23. The EP-WXT trigger 01709130758 is a false trigger
  24. Konus-Wind detection of a bright burst from SGR 1E1841-045 on 2025 January 23
  25. GRB 250121A: Swift/BAT-GUANO localization skymap of a burst
  26. IPN triangulation of a bright burst from SGR 1E1841-045
  27. GRB 250121A: CALET Gamma-Ray Burst Monitor detection
  28. EP250108a: AbAO, CMO and Terskol optical upper limits
  29. Konus-Wind detection of GRB 250118B
  30. GRB 250121A: Fermi GBM Observation
  31. IPN triangulation of GRB 250118B
  32. Konus-Wind detection of GRB 250119B
  33. IPN triangulation of GRB 250119B
  34. GRB 250122A: Fermi GBM Final Real-time Localization
  35. Improved IPN triangulation of GRB 250107C
  36. GRB 250114A: Swift-BAT refined analysis
  37. GRB 250121A: INTEGRAL/SPI-ACS detection
  38. GRB 250121A: Fermi-LAT detection
  39. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  40. GRB 250119C: Swift/BAT-GUANO localization skymap of a short burst
  41. GRB 250119B: Swift/BAT-GUANO localization skymap of a long burst
  42. GRB 250121A: Fermi GBM Final Real-time Localization
  43. Fermi-LAT Gamma-ray Observations of IceCube-241224A
  44. GRB 250118A: Swift/BAT-GUANO localization skymap of a short burst
  45. GRB 250119B: Fermi GBM Observation
  46. EP250108a/AT2025kg: 1.3m DFOT Optical observations
  47. Konus-Wind detection of GRB 250117A
  48. IPN triangulation of GRB 250117A (short)
  49. ATCA detection of possible radio counterpart to GRB 250114A
  50. EP250108a / SN2025kg: Non-detection from ATCA radio follow-up observations
  51. GRB 250119B: INTEGRAL/SPI-ACS detection
  52. LIGO/Virgo/KAGRA S250119cv: GLADEnet Completeness: Potential Host Galaxies in the 90% Credible Volume
  53. EP 250108A: Late-time optical observation by LCO
  54. GRB 250117A: SVOM/GRM observation of a short burst
  55. LIGO/Virgo/KAGRA S250105bn: 1 counterpart neutrino candidate event from an IceCube neutrino search
  56. LIGO/Virgo/KAGRA S250119cv: Updated NED Galaxies in the Localization Volume
  57. LIGO/Virgo/KAGRA S250119cv: Updated Sky localization and EM Bright Classification
  58. GRB 250119C: Fermi GBM Final Real-time Localization
  59. LIGO/Virgo/KAGRA S250119cv: NED Galaxies in the Localization Volume
  60. GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst
  61. EP250108a / SN2025kg: Gemini GMOS-S confirmation of an associated broad-lined SN Ic
  62. LIGO/Virgo/KAGRA S250119cv: Identification of a GW compact binary merger candidate
  63. LIGO/Virgo/KAGRA S250119ag: Updated Sky localization
  64. EP250108a/AT 2025kg: NOT spectroscopy in agreement with SN Ic-BL
  65. EP250108a / AT 2025kg: the kangaroo is hopping, evidence for optical rebrightening
  66. GRB 250117A: GECAM observation of a short burst
  67. LIGO/Virgo/KAGRA S250118dp: Updated Sky localization
  68. GRB 250119B: BALROG localization (Fermi Trigger 758968026 / GRB 250119352)
  69. GRB 250119B: Fermi GBM Final Real-time Localization
  70. LIGO/Virgo/KAGRA S250119ag: Identification of a GW compact binary merger candidate
  71. GRB 250119A: Fermi GBM Final Real-time Localization
  72. GRB 250118A: Fermi GBM Final Real-time Localization
  73. LIGO/Virgo/KAGRA S250118dp: Identification of a GW compact binary merger candidate
  74. LIGO/Virgo/KAGRA S250118t: Updated Sky localization
  75. LIGO/Virgo/KAGRA S250118az: Identification of a GW compact binary merger candidate
  76. EP250108a / AT2025kg: GMG Optical Observations
  77. LIGO/Virgo/KAGRA S250118t: Identification of a GW compact binary merger candidate
  78. EP250108a / AT2025kg: VLA radio upper limit
  79. Fermi Gamma-ray Burst Monitor trigger 758829338/250117747 is not a GRB
  80. Konus-Wind detection of GRB 250116A
  81. GRB 250116A: GECAM-B detection of a long burst
  82. GRB 241217A / EP241217B: radio detection with the VLA
  83. GRB 250116A: INTEGRAL/SPI-ACS and PICsIT detection
  84. Swift Trigger 1282245 is not a GRB
  85. GRB 250116A: Fermi-LAT detection
  86. GRB 250116A: Fermi GBM Observation of an Extremely Interesting Burst
  87. GRB 250114B: Swift-XRT afterglow detection
  88. GRB 250114B: SVOM/VT upper limit
  89. Fermi Gamma-ray Burst Monitor trigger 758659047/250115776 is not a GRB
  90. EP250108a: MeerKAT radio upper limit
  91. LIGO/Virgo/KAGRA S250114ax: Updated NED Galaxies in the Localization Volume
  92. GRB 250101A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations and rebrightening.
  93. LIGO/Virgo/KAGRA S250114ax: Updated Sky localization
  94. Konus-Wind detection of GRB 250113A
  95. IPN triangulation of GRB 250113A
  96. GRB 250114B: Liverpool Telescope optical upper limit
  97. LIGO/Virgo/KAGRA S250114ax: GLADEnet Completeness: Potential Host Galaxies in the 90% Credible Volume
  98. GRB 250114B : MITSuME Akeno optical afterglow candidate detection
  99. GRB 250114B: Swift-XRT observations
  100. GRB 250114A: LCO optical counterpart detection.

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