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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"

32692 results found.

  1. GRB 250103B: LCO/1m optical afterglow candidate detection
  2. GRB 250103B: VLT/X-shooter spectroscopic redshift z = 1.416
  3. GRB 250103A: Swift-XRT observations
  4. GRB 250101A: 1.3m DFOT optical afterglow detection
  5. GRB 241229A: 1.3m DFOT upper limit
  6. GRB 241228B: 1.3m DFOT Optical observations
  7. GRB 241228A: 1.3m DFOT upper limit
  8. GRB 250103A: NOT spectroscopic redshift
  9. GRB 250103B：SVOM/VT optical counterpart
  10. LIGO/Virgo/KAGRA S250104v: Identification of a GW compact binary merger candidate
  11. GRB 250103A: Montarrenti Observatory optical detection
  12. GRB 250101A: further LCOGT optical afterglow observations
  13. GRB 250103A: Redshift 4.01 from OSIRIS+/GTC
  14. GRB 250103A: NOT optical observations
  15. GRB 250103A: TSHAO optical upper limit
  16. GRB 250103A: Fermi GBM Observation
  17. GRB 250103B: LCOGT Optical Upper Limit
  18. IceCube-250102A: Upper limits from a search for additional neutrino events in IceCube
  19. Swift GRB 250103B: Global MASTER-Net observations report
  20. GRB 250103A: SVOM/VT optical counterpart confirmation
  21. EP250101a: Liverpool Telescope optical upper limit
  22. GRB 250103A: Swift ToO observations
  23. IceCube-250101A: Upper limits from a search for additional neutrino events in IceCube
  24. GRB 250101a: Liverpool Telescope optical follow-up
  25. GRB 250103B: SVOM detection of a long burst
  26. GRB 250103A: Xinglong 2.16m Optical Candidate
  27. Fermi GRB 250102A: Global MASTER-Net observations report
  28. GRB 250101B: SVOM/GRM observation
  29. GRB 250103A: GOTO optical upper limit
  30. GRB 250103A: SVOM/C-GFT optical upper limit
  31. GRB 250101A: NUTTelA-TAO / BSTI Optical Limits
  32. EP241231b: optical upper limit with the Liverpool Telescope
  33. EP250101a: Xinglong optical upper limit
  34. GRB 250101A: Swift-BAT refined analysis
  35. GRB 250101A: further SAO RAS optical observations
  36. GRB 250101A: LCO optical counterpart detection
  37. GRB 250101A NUTTelA-TAO / BSTI Early Measurements
  38. GRB 250101A: GMG spectroscopic redshift at z ~ 2.481
  39. GRB 250101A: Swift/UVOT Detection
  40. GRB 250101A: 1.6m Mephisto multi-band optical followup
  41. GRB 250101A: Montarrenti Observatory optical observations and rebrightening
  42. GRB 250101A: LCOGT optical afterglow detection
  43. GRB 250101A: OASDG optical observations
  44. Fermi GRB 250101B: Global MASTER-Net observations report
  45. GRB 250101A: SAO RAS observations of optical brightening
  46. GRB 250101A: AKO Optical Afterglow Detection
  47. GRB 250101A: SAO RAS optical observations
  48. LIGO/Virgo/KAGRA S250101k: Updated Sky localization and Source Classification
  49. GRB 250101A: Xinglong-2.16m spectroscopic redshift
  50. GRB 250101A: SVOM/C-GFT early optical observations
  51. LIGO/Virgo/KAGRA S250101k: Upper limits from Fermi-GBM Observations
  52. GRB 250101A: MASTER earlier OT observations with SOSS emission features
  53. GRB 250101A: Nanshan/HMT optical observations
  54. GRB 250101A : GIT optical detection
  55. GRB 250101A: GMG Optical Observation
  56. GRB 241217a/EP241217b: ATCA Radio Detection
  57. EP241217a: VLA Radio Detection

  58. LIGO/Virgo/KAGRA S250101k: Identification of a GW compact binary merger candidate
  59. GRB 241229B: Continued CrAO ZTSh observations
  60. LIGO/Virgo/KAGRA S241231bg: Updated Sky localization and EM Bright Classification
  61. LIGO/Virgo/KAGRA S241230ev: Updated Sky localization
  62. LIGO/Virgo/KAGRA S241230bd: Updated Sky localization
  63. GRB 241229A: EP-FXT X-ray afterglow confirmation
  64. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  65. GRB 241229B: SVOM/GRM observation
  66. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  67. EP241217A: J band upper limit by SYSU 80cm telescope
  68. LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate
  69. GRB 241229B: SAO RAS optical upper limit
  70. GRB 241228B: SAO RAS optical observations
  71. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  72. GRB 241229A: SAO RAS optical observations
  73. GRB 241229B: SVOM/VT optical candidate
  74. GRB 241229A: Swift-XRT observations
  75. Konus-Wind detection of GRB 241228A
  76. GRB 241229A: EP-FXT afterglow candidates
  77. EP240702a: 7DT Optical upper limits
  78. GRB 240606B: 7DT Optical upper limits
  79. LIGO/Virgo/KAGRA S241230bd: Identification of a GW compact binary merger candidate
  80. GRB 241229B: Swift-BAT refined analysis
  81. LIGO/Virgo/KAGRA S241225v: Updated Sky localization
  82. LIGO/Virgo/KAGRA S241225c: Updated Sky localization and EM Bright Classification
  83. GRB241229B: UVOT upper limits
  84. GRB 241228B: D50 optical detection
  85. GRB 241228B: Fermi GBM Observation
  86. GRB 241229B: Fermi GBM Observation
  87. GRB 241229A: Swift ToO observations
  88. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  89. GRB 241228A: Mondy optical afterglow observations
  90. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  91. Swift GRB 241229B: Global MASTER-Net observations report
  92. GRB 241229A: GOTO optical upper limits
  93. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  94. GRB 241228A: NOT optical upper limits
  95. GRB 241228B: LCO optical observation
  96. GRB 241228A: Swift-BAT refined analysis
  97. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  98. Fermi GRB 241228B: Global MASTER-Net observations report
  99. GRB 241228A: Fermi GBM Observation
  100. GRB241228B: GROWTH-India Telescope optical observations

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