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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

16226 results found.

  1. GRB 240825A: Swift/UVOT Detection
  2. GRB 240825A: REM detection of the optical/NIR afterglow
  3. GRB 240825A: Montarrenti Observatory optical observations
  4. GRB 240825A: Enhanced Swift-XRT position
  5. GRB 240825A: LCO optical observations
  6. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  7. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  8. GRB 240824B: NOT optical upper limit
  9. GRB 240825A: GMG Optical Observation
  10. GRB 240825A: 1.6m Mephisto multi-band detection
  11. GRB 240825A: AKO Optical Afterglow Detection
  12. GRB 240825A: Skynet Optical Afterglow observations
  13. GRB 240825A: Nanshan/HMT optical afterglow observations
  14. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  15. GRB 240824A: SVOM/C-GFT optical upper limit
  16. GRB 240824B: Swift-XRT afterglow detection
  17. GRB 240824A: Swift/UVOT Upper Limits
  18. GRB 240821A: Swift/UVOT observations of the XRT sources.
  19. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  20. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  21. GRB 240824A: Skynet Optical Afterglow Discovery
  22. GRB 240824A: Swift detection of a burst
  23. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  24. GRB 240821A: Colibri Optical Upper Limit
  25. EP240820a: PRIME J-band Observations
  26. GRB 240822A: AstroSat CZTI detection of a short burst
  27. GRB 240821A: REM optical/NIR upper limits
  28. GRB 240821A: LCO optical observations
  29. GRB 240821A: JinShan optical upper limits
  30. GRB 240809A: Mondy and AbAO Optical Observations
  31. GRB 240821A: GMG Optical Upper Limit
  32. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  33. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  34. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  35. EP240820a: TRT optical upper limit
  36. EP240820a: EP detection of a fast X-ray transient
  37. EP240816a: PRIME upper limits
  38. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  39. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  40. GRB 240819A: X-ray follow-up observation with EP-FXT
  41. EP240816b: Liverpool Telescope optical follow-up observations
  42. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  43. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  44. EP240816b: TRT optical upper limit
  45. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  46. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  47. LIGO/Virgo/KAGRA S240813c: Identification of a GW compact binary merger candidate
  48. EP240807a: PRIME H-band upper limits
  49. GRB 240812B: AstroSat CZTI detection of a long burst
  50. GRB 240811A: Bassano Bresciano Observatory upper limit
  51. GRB 240811A: Swift-XRT refined Analysis
  52. GRB 240811A: Swift/UVOT Upper Limits
  53. EP240801a: Assy-Turgen optical observations
  54. GRB 240811A: LCOGT Optical Upper Limit
  55. GRB 240811A: Enhanced Swift-XRT position
  56. GRB 240811A: Upper limits with Mephisto
  57. GRB 240811A: Swift detection of a burst
  58. GRB 240809A: REM detection of the optical afterglow
  59. GRB 240809A: Bassano Bresciano Observatory optical observations
  60. GRB 240809A: GIT afterglow observations
  61. GRB 240809A: Swift/UVOT Detection
  62. GRB 240809A: Swift-XRT refined Analysis
  63. IPN triangulation of GRB 240807A / EP 240807a
  64. X-ray Transient EP240807a: PRIME near-infrared upper limits
  65. GRB 240809A: JinShan optical observations
  66. GRB 240809A: Enhanced Swift-XRT position
  67. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  68. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  69. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  70. GRB 240805A: ATCA Radio Upper Limits
  71. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  72. EP240806A: Liverpool Telescope optical follow-up observations
  73. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  74. EP240807a: EP-WXT detection of a fast X-ray transient
  75. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  76. GRB 240805B: GIT optical upper limit
  77. EP240806a: LCOGT optical counterpart detection
  78. GRB 240805B Bassano Bresciano Observatory upper limit
  79. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  80. EP240806a: EP-FXT detection of the X-ray emission
  81. EP 240806A: LCO optical observations
  82. EP240806a: EP-WXT detection of a fast X-ray transient
  83. GRB 240805B: Optical detection with 1.6m Mephisto
  84. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  85. GRB 240805B: Swift/UVOT Upper Limits
  86. GRB 240805A: Swift/UVOT Upper Limits
  87. GRB 240805B: BTA optical afterglow candidate
  88. GRB 240805B: Enhanced Swift-XRT position
  89. GRB 240805B: LCOGT Optical Upper Limits
  90. GRB 240805B: JinShan optical upper limits
  91. EP240801a: BTA BVRI photometry
  92. Swift GRB 240805A: Global MASTER-Net observations report
  93. GRB 240805A: Swift-XRT refined Analysis
  94. GRB 240805B: Swift detection of a burst
  95. EP240801a: Continued optical observations at ZTSh (CraO)
  96. EP240804a: NOT optical counterpart detection
  97. EP240804a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  98. EP240802a: Montarrenti Observatory optical upper limit
  99. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  100. EP240802A: Bassano Bresciano Observatory upper limit

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