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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16144 results found.

  1. GRB 240825A: ALMA detection
  2. GRB 240825A: SAO RAS optical observations
  3. GRB 240824A: GIT optical upper limit
  4. GRB 240825A: TNG optical photometry and spectroscopy
  5. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  6. GRB 240825A: GMG Continued Optical Observation on the Second Night
  7. GRB 240824B: Ondrejov D50 optical limit
  8. GRB 240825A: KAIT optical observations
  9. GRB 240825A: PRIME near-infrared detection
  10. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  11. GRB 240825A: AKO Optical Follow-Up Observations
  12. GRB 240825A: REM detection of the optical/NIR afterglow
  13. GRB 240825A: VLT/X-shooter redshift
  14. GRB 240825A: SVOM/C-GFT optical observations
  15. GRB 240825A: Montarrenti Observatory optical observations
  16. GRB 240825A: MASTER optical counterpart observation
  17. GRB 240825A: LCO optical observations
  18. GRB 240824B: KAIT optical upper limit
  19. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  20. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  21. GRB 240824B: NOT optical upper limit
  22. GRB 240825A: GMG Optical Observation
  23. GRB 240825A: 1.6m Mephisto multi-band detection
  24. GRB 240825A: AKO Optical Afterglow Detection
  25. GRB 240825A: Skynet Optical Afterglow observations
  26. GRB 240825A: Nanshan/HMT optical afterglow observations
  27. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  28. GRB 240824A: SVOM/C-GFT optical upper limit
  29. GRB 240824A: Swift/UVOT Upper Limits
  30. GRB 240824A: Retraction of GCN 37255
  31. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  32. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  33. GRB 240824A: KAIT optical upper limit
  34. GRB 240824A: Skynet Optical Afterglow Discovery
  35. GRB 240824A: Swift detection of a burst
  36. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  37. GRB 240821A: Colibri Optical Upper Limit
  38. GRB 240821A: REM optical/NIR upper limits
  39. GRB 240821A: LCO optical observations
  40. GRB 240821A: JinShan optical upper limits
  41. GRB 240809A: Mondy and AbAO Optical Observations
  42. GRB 240821A: SVOM/VT follow-up and optical upper limit
  43. GRB 240821A: GMG Optical Upper Limit
  44. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  45. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  46. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  47. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  48. EP240820a: TRT optical upper limit
  49. GRB 240819A: KAIT optical upper limit
  50. GRB 240819A : an X-ray transient detected by SVOM/ECLAIRs
  51. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  52. EP240816b: Liverpool Telescope optical follow-up observations
  53. EP240816a: BOOTES-6/DPRT optical upper limit
  54. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  55. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  56. EP240816b: KAIT optical upper limit
  57. EP240816b: TRT optical upper limit
  58. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  59. GRB 240809A: ATA radio non-detection
  60. GRB 240809A: VLA detection
  61. GRB 240811A: Bassano Bresciano Observatory upper limit
  62. GRB 240811A: Swift/UVOT Upper Limits
  63. EP240801a: Assy-Turgen optical observations
  64. GRB 240811A: LCOGT Optical Upper Limit
  65. GRB 240811A: Upper limits with Mephisto
  66. GRB240809A: Liverpool Telescope optical follow-up observations
  67. GRB 240809A: REM detection of the optical afterglow
  68. GRB 240809A: Bassano Bresciano Observatory optical observations
  69. GRB 240809A: Conclusive redshift from VLT
  70. GRB 240809A: KAIT optical observations
  71. GRB 240809A: GIT afterglow observations
  72. GRB 240809A: Tentative redshift from NOT
  73. GRB 240809A: JinShan optical observations
  74. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  75. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  76. EP240807a: STEP/T80S optical limits
  77. EP-WXT trigger 01709018832: KAIT optical observations of the star flare
  78. EP240802a/GRB240802A: KAIT optical upper limit
  79. EP240806A: Liverpool Telescope optical follow-up observations
  80. The EP-WXT trigger 01709018832 on August 7th is likely a flaring star
  81. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  82. GRB 240805B: GIT optical upper limit
  83. EP240806a: KAIT optical observations
  84. EP240804a (GRB 240804B): NOT optical observations
  85. EP240806a: LCOGT optical counterpart detection
  86. GRB 240805B Bassano Bresciano Observatory upper limit
  87. GRB 240805B: JinShan optical afterglow detection
  88. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  89. EP240806a: EP-FXT detection of the X-ray emission
  90. EP 240806A: LCO optical observations
  91. EP240806a: GSP optical counterpart detection
  92. GRB 240805B: Optical detection with 1.6m Mephisto
  93. EP240804a: BOOTES-6/DPRT optical detection
  94. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  95. GRB 240805B: Swift/UVOT Upper Limits
  96. GRB 240805A: Swift/UVOT Upper Limits
  97. GRB 240805B: BTA optical afterglow candidate
  98. GRB 240805B: LCOGT Optical Upper Limits
  99. GRB 240805B: JinShan optical upper limits
  100. EP240801a: BTA BVRI photometry

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