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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"

32756 results found.

  1. GRB 250101A NUTTelA-TAO / BSTI Early Measurements
  2. GRB 250101A: GMG spectroscopic redshift at z ~ 2.481
  3. GRB 250101A: Swift/UVOT Detection
  4. GRB 250101A: 1.6m Mephisto multi-band optical followup
  5. GRB 250101A: Montarrenti Observatory optical observations and rebrightening
  6. GRB 250101A: LCOGT optical afterglow detection
  7. GRB 250101A: OASDG optical observations
  8. Fermi GRB 250101B: Global MASTER-Net observations report
  9. GRB 250101A: SAO RAS observations of optical brightening
  10. GRB 250101A: AKO Optical Afterglow Detection
  11. GRB 250101A: SAO RAS optical observations
  12. LIGO/Virgo/KAGRA S250101k: Updated Sky localization and Source Classification
  13. GRB 250101A: Xinglong-2.16m spectroscopic redshift
  14. GRB 250101A: SVOM/C-GFT early optical observations
  15. LIGO/Virgo/KAGRA S250101k: Upper limits from Fermi-GBM Observations
  16. GRB 250101A: MASTER earlier OT observations with SOSS emission features
  17. GRB 250101A: Nanshan/HMT optical observations
  18. GRB 250101A : GIT optical detection
  19. GRB 250101A: GMG Optical Observation
  20. GRB 241217a/EP241217b: ATCA Radio Detection
  21. EP241217a: VLA Radio Detection

  22. LIGO/Virgo/KAGRA S250101k: Identification of a GW compact binary merger candidate
  23. GRB 241229B: Continued CrAO ZTSh observations
  24. LIGO/Virgo/KAGRA S241231bg: Updated Sky localization and EM Bright Classification
  25. LIGO/Virgo/KAGRA S241230ev: Updated Sky localization
  26. LIGO/Virgo/KAGRA S241230bd: Updated Sky localization
  27. GRB 241229A: EP-FXT X-ray afterglow confirmation
  28. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  29. GRB 241229B: SVOM/GRM observation
  30. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  31. EP241217A: J band upper limit by SYSU 80cm telescope
  32. LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate
  33. GRB 241229B: SAO RAS optical upper limit
  34. GRB 241228B: SAO RAS optical observations
  35. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  36. GRB 241229A: SAO RAS optical observations
  37. GRB 241229B: SVOM/VT optical candidate
  38. GRB 241229A: Swift-XRT observations
  39. Konus-Wind detection of GRB 241228A
  40. GRB 241229A: EP-FXT afterglow candidates
  41. EP240702a: 7DT Optical upper limits
  42. GRB 240606B: 7DT Optical upper limits
  43. LIGO/Virgo/KAGRA S241230bd: Identification of a GW compact binary merger candidate
  44. GRB 241229B: Swift-BAT refined analysis
  45. LIGO/Virgo/KAGRA S241225v: Updated Sky localization
  46. LIGO/Virgo/KAGRA S241225c: Updated Sky localization and EM Bright Classification
  47. GRB241229B: UVOT upper limits
  48. GRB 241228B: D50 optical detection
  49. GRB 241228B: Fermi GBM Observation
  50. GRB 241229B: Fermi GBM Observation
  51. GRB 241229A: Swift ToO observations
  52. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  53. GRB 241228A: Mondy optical afterglow observations
  54. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  55. Swift GRB 241229B: Global MASTER-Net observations report
  56. GRB 241229A: GOTO optical upper limits
  57. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  58. GRB 241228A: NOT optical upper limits
  59. GRB 241228B: LCO optical observation
  60. GRB 241228A: Swift-BAT refined analysis
  61. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  62. Fermi GRB 241228B: Global MASTER-Net observations report
  63. GRB 241228A: Fermi GBM Observation
  64. GRB241228B: GROWTH-India Telescope optical observations
  65. Swift GRB 241228A: Global MASTER-Net observations report
  66. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  67. GRB 241228B: GOTO24jmz optical follow-up observations
  68. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  69. GRB 241228A: GROWTH-India telescope optical upper limit
  70. GRB 241228B: Swift ToO observations
  71. GRB 241228B: TRT optical counterpart confirmation
  72. GRB 241228A: Swift/UVOT Upper Limits
  73. GRB 241228B: GOTO possible optical counterpart candidate
  74. IceCube-241224A: Upper limits from a search for additional neutrino events in IceCube
  75. GRB 241223A: GRBAlpha detection
  76. GRB 241212A: VZLUSAT-2 detection
  77. GRB 241217A/EP241217b: continued SOAR observations
  78. Fermi GRB 241226A: Global MASTER-Net observations report
  79. EP241223a: Mondy AZT-33IK optical observations
  80. GRB 241029A: LCO optical observation
  81. GRB 241223A: Swift-XRT observations
  82. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  83. GRB 241029A: AbAO AS-32 optical observations
  84. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  85. EP241223a
  86. EP241223a: Global MASTER-Net observations report
  87. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  88. GRB241113A: 7DT Optical upper limits
  89. Fermi GRB 241223A: Global MASTER-Net observations report
  90. GRB 241223A: GOTO optical observations summary
  91. GRB 241105A: JWST photometric observations of the host galaxy
  92. GRB 241223A: Swift ToO observations
  93. EP241217a: e-MERLIN radio observations
  94. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  95. GRB 241209B: host galaxy detection and GTC/OSIRIS+ spectroscopy
  96. Fermi GRB 241221A: Global MASTER-Net observations report
  97. GRB 241217A/EP241217b: SOAR afterglow detection
  98. EP241217a: Liverpool Telescope optical upper limit
  99. EP241021a: VLA radio detection
  100. GRB 241218A: Mondy AZT-33IK optical upper limit

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