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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"

20521 results found.

  1. LIGO/Virgo/KAGRA S250328ae: NED Galaxies in the 4-Update Localization Volume
  2. EP250302a: SPI-ACS/INTEGRAL Upper Limit
  3. GRB 250327B: CrAO and SAO RAS Optical Observations
  4. EP250315a: Pan-STARRS r and i-band imaging and photometry
  5. GRB 250327b: Liverpool Telescope optical observations
  6. GRB 250322A: GRANDMA/TNOT optical upper limits
  7. GRB 250327A: SVOM/VT upper limits on the XRT position
  8. LIGO/Virgo/KAGRA S250328ae: Identification of a GW compact binary merger candidate
  9. GRB 250327B: SVOM/COLIBRÍ (F-GFT) follow-up observations
  10. GRB 250327B: Las Cumbres optical counterpart detection
  11. GRB 250327B: 1.6m Mephisto optical observations
  12. GRB 250327B: NOT spectroscopic redshift z = 3.035
  13. GRB 250327B: SVOM/VT optically bright counterpart
  14. GRB 250327B: SAO RAS optical candidate
  15. GRB 250327B: SVOM detection of a burst
  16. GRB 250327A: J-band observations with WINTER
  17. GRB 250327A: SVOM/VT optical candidate
  18. FRB 20250316A: Pan-STARRS r and i-band imaging and photometry
  19. GRB 250327A: DDOTI Optical Observations
  20. GRB 250327A: COLIBRÍ optical upper limit
  21. IPN triangulation of GRB 250322B
  22. LIGO/Virgo/KAGRA S250326y: Identification of a GW compact binary merger candidate
  23. EP250321a: Mondy AZT-33IK Continued Optical Observations
  24. Swift follow-up observations of FRB250316A and EP J120944.2+585060
  25. GRB 250322A: third epoch of NOT optical observations
  26. GRB 250321B: ISON-Kitab RC-36 Optical Upper Limit
  27. FRB 250316A: NOT optical upper limit for the X ray source EP J120944.2+585060
  28. GRB 250322A: further NOT optical observations
  29. EP-WXT trigger 01709133021: Optical upper limit through Kinder observations
  30. GRB 250322A: Swift/UVOT Upper Limits
  31. EP250324A: COLIBRÍ/DDRAGO Optical Observations
  32. FRB 250316A: COLIBRÍ/DDRAGO Optical follow up of the X ray source EP J120944.2+585060
  33. GRB 250321B: Swift-XRT observations
  34. EP250321a: TNOT Observation of Optical Counterpart
  35. FRB 250316A: DDOTI Continued Optical Observations (Third Epoch)
  36. GRB 250322A: VLT optical observations
  37. GRB 250322A: VLT near-infrared observations
  38. FRB 250316A: DDOTI Continued Optical Observations
  39. GRB 250322A: NOT optical upper limits
  40. GRB 250322A: Enhanced Swift-XRT position
  41. GRB 250321B: SVOM/COLIBRÍ (F-GFT) follow-up observations
  42. FRB 20250316A: Kinder optical upper limits of the Einstein Probe candidate X-ray source EP J120944.2+585060
  43. EP250321a: Liverpool Telescope optical follow-up
  44. EP250321a: Mondy AZT-33IK Optical Observations
  45. GRB 250322A: Swift detection of a short burst
  46. FRB 20250316A: detection of a candidate associated X-ray source EP J120944.2+585060 by Einstein Probe
  47. EP250321a: refined analysis of the EP-WXT and EP-FXT observations
  48. EP250321a: KAIT optical observations
  49. EP250321A: COLIBRÍ Continuing Optical Observations
  50. EP250321a: WFST optical observations
  51. EP250321a: Xinglong 216 decaying optical observations
  52. GRB 250321A: Swift-XRT refined Analysis
  53. EP 250321A: Optical counterpart detection by LCO.
  54. EP250321a: Kinder optical follow-up observations
  55. GRB 250321A: Swift/UVOT Upper Limits
  56. GRB 250320B: SVOM/GRM observation of a long burst
  57. EP250321a: LCO optical counterpart detection
  58. EP250321A: COLIBRÍ Optical Observations
  59. GRB 250320B: AstroSat CZTI detection
  60. EP250321a: REM optical/NIR afterglow detection
  61. EP250321a: TRT optical counterpart detection
  62. EP250321a: Einstein Probe detection of an X-ray transient
  63. GRB 250321A: GOTO optical upper limits
  64. GRB 250314A: Keck/NIRC2 J-band upper limit
  65. EP250226a/GRB 250226A: KAIT optical observations
  66. GRB 250321A: Swift detection of a burst
  67. GRB 250309B: Proof-of-concept for Joint ZTF+EP Experiment
  68. GRB 250317B: Mondy AZT-33IK Continued Optical Observations
  69. GRB 250317B: SVOM/COLIBRI (F-GFT) follow-up observations
  70. EP250302a: VLA observations
  71. LIGO/Virgo/KAGRA S250319bu: Identification of a GW compact binary merger candidate
  72. GRB 250317C: SVOM/GRM observation of a long burst
  73. GRB 250317B: Leavitt Observatory optical upper limit
  74. GRB 250317B: Mondy AZT-33IK Optical Observations
  75. GRB 250317B: NOT optical observations suggest an optical plateau phase
  76. GRB 250317B: OHP/T193 optical observations
  77. GRB250312A: Swift/UVOT Upper Limits
  78. GRB 250317B: REM optical/NIR observations
  79. GRB 250316A: Swift/UVOT Upper Limits
  80. GRB 250314A: REM optical/NIR upper limits
  81. GRB 250316A: AbAO AS-32 Optical Upper Limit
  82. EP 250317B: Fading optical counterpart detection by LCO
  83. GRB 250316A: Swift-XRT afterglow detection
  84. GRB 250317B: LCO detection of the fading optical afterglow
  85. GRB 250317B: SVOM/VT detection of an optical candidate from VHF data
  86. GRB 250317B: SVOM/F-GFT (COLIBRÍ) Detection of a Fading Optical Counterpart
  87. GRB 250317B: SVOM detection of a burst / correction to GRB name of GCN 39752
  88. GRB 250317B: SVOM detection of a burst
  89. EP250315a: refined analysis of the EP-WXT and EP-FXT observations
  90. GRB 250314A: Swift/UVOT Upper Limits
  91. GRB 250314A: Swift XRT Detection
  92. EP250315a: optical counterpart candidate detected by Gemini North
  93. GRB 250314A: VLT/X-shooter dropout, redshift z ~ 7.3
  94. EP250315a: Einstein Probe detection of an X-ray transient
  95. GRB 250226A: Mondy AZT-33IK and Koshka Zeiss-1000 Optical Upper Limits
  96. SVOM/MXT upper limit on GRB 250314A
  97. GRB 250314A: SVOM/VT upper limit
  98. GRB 250314A: NOT near-infrared candidate counterpart
  99. GRB 250313A: Fermi GBM Detection
  100. GRB 250313A: Swift-XRT observations

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