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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"

21927 results found.

  1. EP250108a: EP-FXT follow-up observation
  2. EP250108a: NOT optical observations
  3. EP-WXT trigger EP250109a：Xinglong optical follow-up observations
  4. GRB 250109a: GMG Optical Upper Limit
  5. EP250109a: Swift/UVOT non-detection
  6. Konus-Wind detection of GRB 250107D (short/hard)
  7. IPN triangulation of GRB 250107D (short/hard)
  8. EP250108a: Liverpool Telescope likely optical counterpart
  9. GRB 250108B: 1.3m DFOT upper limit
  10. GRB 250108B: REM optical/NIR upper limits
  11. EP250109a: Global MASTER-Net observations report
  12. GRB 250101A: Terskol K-800 optical observations
  13. EP250109a: Swift/XRT non-detection
  14. GRB 250108A: Swift/UVOT Upper Limits
  15. LIGO/Virgo/KAGRA S250109bi: Identification of a GW compact binary merger candidate
  16. GRB 250108A: NOT optical upper limit
  17. EP250108a: EP-WXT detection of an X-ray transient
  18. LIGO/Virgo/KAGRA S250109f: Identification of a GW compact binary merger candidate
  19. GRB 250103A: 1.6m Mephisto optical observations
  20. GRB 250108A: Swift-XRT afterglow detection
  21. LIGO/Virgo/KAGRA S250108eo: Identification of a GW compact binary merger candidate
  22. GRB 250108B: Swift/UVOT Upper Limits
  23. GRB 250103A: Swift-XRT afterglow detection
  24. GRB 250108B: Enhanced Swift-XRT position
  25. GRB 250108B: Swift detection of a burst
  26. GRB 250108A: SVOM detection of a soft long burst
  27. GRB 241228B: Fermi-LAT detection
  28. GRB 250101A: J band upper limit by SYSU 80cm telescope
  29. EPWXT01709129925: Xinglong optical observations
  30. GRB 250106A: NOT optical observations
  31. GRB 250103B: REM optical/NIR upper limits
  32. GRB 250101A: REM optical/NIR counterpart detection
  33. GRB 250106A: SVOM detection of a long burst
  34. GRB 250103B: Swift-XRT refined Analysis
  35. GRB 250103B: LCO/1m optical afterglow candidate detection
  36. GRB 250103A: Bassano Bresciano Observatory upper limit
  37. GRB 250101A: 1.3m DFOT optical afterglow detection
  38. GRB 241229A: 1.3m DFOT upper limit
  39. GRB 241228B: 1.3m DFOT Optical observations
  40. GRB 241228A: 1.3m DFOT upper limit
  41. LIGO/Virgo/KAGRA S250104v: Identification of a GW compact binary merger candidate
  42. GRB 250103A: Montarrenti Observatory optical detection
  43. GRB 250101A: further LCOGT optical afterglow observations
  44. GRB 250103A: TSHAO optical upper limit
  45. GRB 250103A: Fermi GBM Observation
  46. GRB 250103B: LCOGT Optical Upper Limit
  47. EP250101a: Liverpool Telescope optical upper limit
  48. GRB 250101a: Liverpool Telescope optical follow-up
  49. GRB 250103B: SVOM detection of a long burst
  50. GRB 250103B: Swift detection of a burst
  51. GRB 250103A: Xinglong 2.16m Optical Candidate
  52. GRB 250101B: SVOM/GRM observation
  53. GRB 250103A: GOTO optical upper limit
  54. GRB 250103A: SVOM/C-GFT optical upper limit
  55. GRB 250101A: NUTTelA-TAO / BSTI Optical Limits
  56. EP241231b: optical upper limit with the Liverpool Telescope
  57. GRB 250103A: SVOM detection of a long burst (duplicate submission)
  58. GRB 250103A: SVOM detection of a long burst
  59. EP250101a: Xinglong optical upper limit
  60. LIGO/Virgo/KAGRA S241230bd: Upper limits from Swift/BAT-GUANO
  61. GRB 250101A: further SAO RAS optical observations
  62. GRB 250101A: LCO optical counterpart detection
  63. GRB 250101A NUTTelA-TAO / BSTI Early Measurements
  64. GRB 250101A: Swift/UVOT Detection
  65. GRB 250101A: 1.6m Mephisto multi-band optical followup
  66. GRB 250101A: Montarrenti Observatory optical observations and rebrightening
  67. GRB 250101A: LCOGT optical afterglow detection
  68. GRB 250101A: OASDG optical observations
  69. GRB 250101A: BOOTES-4/MET optical afterglow detection
  70. GRB 250101A: AKO Optical Afterglow Detection
  71. GRB 250101A: SAO RAS optical observations
  72. GRB 250101A: Enhanced Swift-XRT position
  73. GRB 250101A: SVOM/C-GFT early optical observations
  74. GRB 250101A : GIT optical detection
  75. GRB 250101A: GMG Optical Observation
  76. GRB 250101A: Swift detection of a burst with an optical counterpart
  77. LIGO/Virgo/KAGRA S241231du: Coverage and upper limit from MAXI/GSC observations
  78. LIGO/Virgo/KAGRA S250101k: Identification of a GW compact binary merger candidate
  79. GRB 241229B: Continued CrAO ZTSh observations
  80. LIGO/Virgo/KAGRA S241231bg: Updated Sky localization and EM Bright Classification
  81. GRB 241229A: EP-FXT X-ray afterglow confirmation
  82. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  83. GRB 241229B: SVOM/GRM observation
  84. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  85. EP241217A: J band upper limit by SYSU 80cm telescope
  86. LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate
  87. GRB 241229B: SAO RAS optical upper limit
  88. GRB 241228B: SAO RAS optical observations
  89. GRB 241229A: SAO RAS optical observations
  90. Konus-Wind detection of GRB 241228A
  91. EP240702a: 7DT Optical upper limits
  92. GRB 240606B: 7DT Optical upper limits
  93. LIGO/Virgo/KAGRA S241230bd: Identification of a GW compact binary merger candidate
  94. LIGO/Virgo/KAGRA S241225c: Updated Sky localization and EM Bright Classification
  95. GRB241229B: UVOT upper limits
  96. GRB 241228B: Swift-XRT afterglow detection
  97. GRB 241229B: Fermi GBM Observation
  98. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  99. GRB 241228A: Mondy optical afterglow observations
  100. GRB 241229A: GOTO optical upper limits

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