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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"

46016 results found.

  1. GRB 250126A: MAXI/GSC detection
  2. EP250108a / SN 2025kg: Refined Analysis of EP-WXT Detection
  3. GRB 250126A: BALROG localization (Fermi Trigger 759560335 / GRB 250126208)
  4. GRB 250126A: Fermi GBM Final Real-time Localization
  5. GECAM-A detection of a bright burst from SGR 1E1841-045
  6. GRB 250118A: Fermi GBM Observation
  7. EP250125a: Optical upper limit with Kinder observations
  8. EP250125a: REM optical counterpart detection
  9. GRB 250119C: Fermi GBM Observation
  10. EP250125a: Swift/XRT detection of a fading counterpart
  11. EP250125a: a new X-ray transient detected by Einstein Probe
  12. EP250125a: Gemini-South optical afterglow discovery and redshift z = 2.89
  13. The EP-WXT trigger 01709130758 is a false trigger
  14. The EP-WXT trigger 01709130758 is a false trigger
  15. Konus-Wind detection of a bright burst from SGR 1E1841-045 on 2025 January 23
  16. GRB 250121A: Swift/BAT-GUANO localization skymap of a burst
  17. IPN triangulation of a bright burst from SGR 1E1841-045
  18. GRB 250121A: CALET Gamma-Ray Burst Monitor detection
  19. EP250108a: AbAO, CMO and Terskol optical upper limits
  20. Konus-Wind detection of GRB 250118B
  21. GRB 250121A: Fermi GBM Observation
  22. IPN triangulation of GRB 250118B
  23. Konus-Wind detection of GRB 250119B
  24. IPN triangulation of GRB 250119B
  25. GRB 250122A: Fermi GBM Final Real-time Localization
  26. Improved IPN triangulation of GRB 250107C
  27. GRB 250114A: Swift-BAT refined analysis
  28. GRB 250121A: INTEGRAL/SPI-ACS detection
  29. GRB 250121A: Fermi-LAT detection
  30. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  31. GRB 250119C: Swift/BAT-GUANO localization skymap of a short burst
  32. GRB 250119B: Swift/BAT-GUANO localization skymap of a long burst
  33. GRB 250121A: Fermi GBM Final Real-time Localization
  34. Fermi-LAT Gamma-ray Observations of IceCube-241224A
  35. GRB 250118A: Swift/BAT-GUANO localization skymap of a short burst
  36. GRB 250119B: Fermi GBM Observation
  37. EP250108a/AT2025kg: 1.3m DFOT Optical observations
  38. Konus-Wind detection of GRB 250117A
  39. IPN triangulation of GRB 250117A (short)
  40. ATCA detection of possible radio counterpart to GRB 250114A
  41. EP250108a / SN2025kg: Non-detection from ATCA radio follow-up observations
  42. GRB 250119B: INTEGRAL/SPI-ACS detection
  43. LIGO/Virgo/KAGRA S250119cv: GLADEnet Completeness: Potential Host Galaxies in the 90% Credible Volume
  44. EP 250108A: Late-time optical observation by LCO
  45. GRB 250117A: SVOM/GRM observation of a short burst
  46. LIGO/Virgo/KAGRA S250105bn: 1 counterpart neutrino candidate event from an IceCube neutrino search
  47. LIGO/Virgo/KAGRA S250119cv: Updated NED Galaxies in the Localization Volume
  48. LIGO/Virgo/KAGRA S250119cv: Updated Sky localization and EM Bright Classification
  49. GRB 250119C: Fermi GBM Final Real-time Localization
  50. LIGO/Virgo/KAGRA S250119cv: NED Galaxies in the Localization Volume
  51. GRB 250117A: Swift/BAT-GUANO localization skymap of a short burst
  52. EP250108a / SN2025kg: Gemini GMOS-S confirmation of an associated broad-lined SN Ic
  53. LIGO/Virgo/KAGRA S250119cv: Identification of a GW compact binary merger candidate
  54. LIGO/Virgo/KAGRA S250119ag: Updated Sky localization
  55. EP250108a/AT 2025kg: NOT spectroscopy in agreement with SN Ic-BL
  56. EP250108a / AT 2025kg: the kangaroo is hopping, evidence for optical rebrightening
  57. GRB 250117A: GECAM observation of a short burst
  58. LIGO/Virgo/KAGRA S250118dp: Updated Sky localization
  59. GRB 250119B: BALROG localization (Fermi Trigger 758968026 / GRB 250119352)
  60. GRB 250119B: Fermi GBM Final Real-time Localization
  61. LIGO/Virgo/KAGRA S250119ag: Identification of a GW compact binary merger candidate
  62. GRB 250119A: Fermi GBM Final Real-time Localization
  63. GRB 250118A: Fermi GBM Final Real-time Localization
  64. LIGO/Virgo/KAGRA S250118dp: Identification of a GW compact binary merger candidate
  65. LIGO/Virgo/KAGRA S250118t: Updated Sky localization
  66. LIGO/Virgo/KAGRA S250118az: Identification of a GW compact binary merger candidate
  67. EP250108a / AT2025kg: GMG Optical Observations
  68. LIGO/Virgo/KAGRA S250118t: Identification of a GW compact binary merger candidate
  69. EP250108a / AT2025kg: VLA radio upper limit
  70. Fermi Gamma-ray Burst Monitor trigger 758829338/250117747 is not a GRB
  71. Konus-Wind detection of GRB 250116A
  72. GRB 250116A: GECAM-B detection of a long burst
  73. GRB 241217A / EP241217B: radio detection with the VLA
  74. GRB 250116A: INTEGRAL/SPI-ACS and PICsIT detection
  75. Swift Trigger 1282245 is not a GRB
  76. GRB 250116A: Fermi-LAT detection
  77. GRB 250116A: Fermi GBM Observation of an Extremely Interesting Burst
  78. GRB 250114B: Swift-XRT afterglow detection
  79. GRB 250114B: SVOM/VT upper limit
  80. Fermi Gamma-ray Burst Monitor trigger 758659047/250115776 is not a GRB
  81. EP250108a: MeerKAT radio upper limit
  82. LIGO/Virgo/KAGRA S250114ax: Updated NED Galaxies in the Localization Volume
  83. GRB 250101A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations and rebrightening.
  84. LIGO/Virgo/KAGRA S250114ax: Updated Sky localization
  85. Konus-Wind detection of GRB 250113A
  86. IPN triangulation of GRB 250113A
  87. GRB 250114B: Liverpool Telescope optical upper limit
  88. LIGO/Virgo/KAGRA S250114ax: GLADEnet Completeness: Potential Host Galaxies in the 90% Credible Volume
  89. GRB 250114B : MITSuME Akeno optical afterglow candidate detection
  90. GRB 250114B: Swift-XRT observations
  91. GRB 250114A: LCO optical counterpart detection.
  92. GRB 250114B: OHP/T193 optical upper limit
  93. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  94. GRB 250114A: Swift-XRT refined Analysis
  95. Integral GRB250114.55: Global MASTER-Net observations report
  96. GRB 250114A: LCOGT optical afterglow i-band detection
  97. GRB 250114B : GIT optical upper limit
  98. GRB 250114B: Swift ToO observations
  99. EP250111a: SAO RAS optical upper limit
  100. LIGO/Virgo/KAGRA S250114ax: NED Galaxies in the Localization Volume

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