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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"

24464 results found.

  1. IceCube Alert 250102.58: Global MASTER-Net observations report
  2. GRB 250103A: SVOM detection of a long burst (duplicate submission)
  3. GRB 250103A: SVOM detection of a long burst
  4. EP250101a: Xinglong optical upper limit
  5. GRB 250102A: Fermi GBM Final Real-time Localization
  6. LIGO/Virgo/KAGRA S241230bd: Upper limits from Swift/BAT-GUANO
  7. GRB 250101A: Swift-BAT refined analysis
  8. IceCube-250102A - IceCube observation of a high-energy neutrino candidate track-like event
  9. GRB 250101A NUTTelA-TAO / BSTI Early Measurements
  10. GRB 250101A: 1.6m Mephisto multi-band optical followup
  11. GRB 250101A: Montarrenti Observatory optical observations and rebrightening
  12. IceCube-250101A - IceCube observation of a high-energy neutrino candidate track-like event
  13. Fermi GRB 250101B: Global MASTER-Net observations report
  14. GRB 250101B: Fermi GBM Final Real-time Localization
  15. LIGO/Virgo/KAGRA S250101k: Updated Sky localization and Source Classification
  16. GRB 250101A: SVOM/C-GFT early optical observations
  17. LIGO/Virgo/KAGRA S250101k: Upper limits from Fermi-GBM Observations
  18. GRB 250101A: MASTER earlier OT observations with SOSS emission features
  19. GRB 250101A: Swift detection of a burst with an optical counterpart
  20. Swift GRB250101.56: Global MASTER-Net observations report
  21. EP241217a: VLA Radio Detection

  22. LIGO/Virgo/KAGRA S241231du: Coverage and upper limit from MAXI/GSC observations
  23. LIGO/Virgo/KAGRA S250101k: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo/KAGRA S241231bg: Updated NED Galaxies in the Localization Volume
  25. LIGO/Virgo/KAGRA S241231bg: Updated Sky localization and EM Bright Classification
  26. LIGO/Virgo/KAGRA S241230ev: Updated Sky localization
  27. LIGO/Virgo/KAGRA S241231bg: NED Galaxies in the Localization Volume
  28. LIGO/Virgo/KAGRA S241230bd: Updated Sky localization
  29. GRB 241229A: EP-FXT X-ray afterglow confirmation
  30. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  31. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  32. LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate
  33. IceCube-Cascade 241228A: Upper limits from a search for additional neutrino events in IceCube
  34. GRB 241229B: SVOM/VT optical candidate
  35. GRB 241229A: Swift-XRT observations
  36. Konus-Wind detection of GRB 241228A
  37. EP240702a: 7DT Optical upper limits
  38. GRB 240606B: 7DT Optical upper limits
  39. Fermi trigger No 757231333: Global MASTER-Net observations report
  40. LIGO/Virgo/KAGRA S241230bd: Identification of a GW compact binary merger candidate
  41. GRB 241229B: Swift-BAT refined analysis
  42. LIGO/Virgo/KAGRA S241225v: Updated Sky localization
  43. LIGO/Virgo/KAGRA S241225c: Updated Sky localization and EM Bright Classification
  44. GRB 241229C: Fermi GBM Final Real-time Localization
  45. GRB 241228B: Fermi GBM Observation
  46. GRB 241229B: Fermi GBM Observation
  47. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  48. GRB 241229B: Swift-XRT refined Analysis
  49. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  50. Swift GRB 241229B: Global MASTER-Net observations report
  51. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  52. GRB 241228A: Swift-BAT refined analysis
  53. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  54. GRB 241229B: Fermi GBM Final Real-time Localization
  55. GRB 241229A: SVOM detection of a long burst
  56. Fermi GRB 241228B: Global MASTER-Net observations report
  57. GRB 241228A: Fermi GBM Observation
  58. GRB241228B: GROWTH-India Telescope optical observations
  59. Swift GRB 241228A: Global MASTER-Net observations report
  60. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  61. GRB 241228A: Swift-XRT refined Analysis
  62. GRB 241228B: GOTO possible optical counterpart candidate
  63. GRB 241228B: Fermi GBM Final Real-time Localization
  64. GRB 241228A: Swift detection of a burst
  65. IceCube-241224A: Upper limits from a search for additional neutrino events in IceCube
  66. LIGO/Virgo/KAGRA S241225c: Two counterpart neutrino candidates from IceCube neutrino searches
  67. GRB 241223A: GRBAlpha detection
  68. GRB 241212A: VZLUSAT-2 detection
  69. Fermi GRB 241226A: Global MASTER-Net observations report
  70. GRB 241226A: Fermi GBM Final Real-time Localization
  71. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  72. GRB 241223A: Fermi GBM Detection
  73. Fermi trigger No 756678579: Global MASTER-Net observations report
  74. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  75. EP241223a
  76. IceCube-241224A - IceCube observation of a high-energy neutrino candidate track-like event
  77. IceCube Alert 241224.30: Global MASTER-Net observations report
  78. EP241223a: Global MASTER-Net observations report
  79. GRB241113A: 7DT Optical upper limits
  80. Fermi GRB 241223A: Global MASTER-Net observations report
  81. GRB 241223A: GOTO optical observations summary
  82. GRB 241105A: JWST photometric observations of the host galaxy
  83. EP241217a: e-MERLIN radio observations
  84. GRB 241223A: BALROG localization (Fermi Trigger 756648531 / GRB 241223506)
  85. GRB 241223A: Fermi GBM Final Real-time Localization
  86. Fermi trigger No 756447119: Global MASTER-Net observations report
  87. Fermi GRB 241221A: Global MASTER-Net observations report
  88. GRB 241221A: Fermi GBM Final Real-time Localization
  89. GRB 241218A: Mondy AZT-33IK optical upper limit
  90. EP241217a : Leavitt Observatory optical upper limit
  91. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  92. EP241217a: 1.6m Mephisto multi-band optical observations
  93. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  94. GRB 241209B: EP-FXT afterglow detection
  95. Konus-Wind detection of GRB 241204A (short/hard)
  96. GRB 241218A: Swift-BAT refined analysis
  97. EP 241217a: Possible J-band detection with WINTER
  98. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  99. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  100. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.

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