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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.

Advanced Search Examples (click to copy):

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

31730 results found.

  1. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  2. Fermi GRB 240905D: Global MASTER-Net observations report
  3. Fermi GRB 240905A: Global MASTER-Net observations report
  4. GRB 240905E: NOT optical upper limits
  5. GRB 240905E: REM optical/NIR upper limits
  6. GRB 240905E: SVOM/GRM observation
  7. GRB 240905E: LCOGT Optical Upper Limit
  8. GRB 240905E: Swift/UVOT Upper Limits
  9. GRB 240905E: SAO RAS optical upper limit
  10. GRB 240825A: Montarrenti Observatory optical follow-up observations
  11. GRB 240905E: Nanshan/HMT optical upper limit
  12. Swift GRB 240905E: Global MASTER-Net observations report
  13. GRB 240819A: Optical upper limits from TESS
  14. GRB 240905D: AstroSat CZTI detection
  15. GRB 240905A: SVOM/GRM observation
  16. Fermi GRB 240905B: Global MASTER-Net observations report
  17. GRB 240905B: AstroSat CZTI detection and localization
  18. GRB 240825A: ATCA Detection of Radio Counterpart
  19. Swift GRB 240904A: Global MASTER-Net observations report
  20. GRB 240828A: SVOM/GRM observation
  21. Fermi Gamma-ray Burst Monitor trigger 240831A is not a GRB
  22. LIGO/Virgo/KAGRA S240902bq: Updated Sky localization
  23. GRB 240828A: GECAM detection
  24. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  25. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  26. GRB 240825A: MeerLICHT afterglow detection
  27. GRB 240828A: SAO RAS AS-500(2) optical observations
  28. GRB 240821A: VLT spectroscopic observations
  29. GRB 240825A: TSHAO Optical Upper Limit
  30. GRB 240829B: GRBAlpha detection
  31. GRB240828B: REM optical/NIR upper limits
  32. GRB 240828B: AbAO optical upper limit
  33. GRB 240825A: SOAR observations
  34. GRB 240828B: Mephisto optical upper limit
  35. GRB 240828B: GRANDMA Optical Upper Limit
  36. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  37. LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
  38. GRB 240829A: Swift-BAT refined analysis
  39. GRB 240825A: Swift-BAT refined analysis
  40. LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
  41. GRB 240825A: MeerKAT detection
  42. GRB 240828B: J-band upper limit from WINTER
  43. GRB 240828B: GMG Optical Upper Limit
  44. GRB 240828A: KAIT continued optical observations
  45. GRB 240828B: GWAC-F50A optical upper limit
  46. GRB 240828B: SVOM/C-GFT optical upper limit
  47. GRB 240828B: SAO RAS optical upper limit
  48. GRB 240828B: KAIT optical upper limit
  49. GRB 240828A: SAO RAS optical observations
  50. GRB 240828A: Fermi GBM Observation
  51. GRB 240629A: First GRB Detected by BurstCube
  52. GRB 240828A: KAIT Optical Afterglow Candidate
  53. GRB 240825A: SVOM/VT optical detection
  54. GRB 240825A: further SAO RAS optical observations
  55. GRB 240825A: iTelescope optical observations
  56. GRB 240828A: Fermi-LAT detection
  57. GRB 240828A: Tiled Swift observations
  58. GRB 240828A: AstroSat CZTI detection of a long burst
  59. GRB 240825A: Upper limits from a neutrino search with IceCube
  60. GRB 240819A as a likely X-Ray Flash
  61. GRB 240828B: Swift ToO observations
  62. GRB 240821A: PRIME near-infrared observations
  63. GRB 240825A: VLA detection
  64. Fermi GRB 240828A: Global MASTER-Net observations report
  65. SVOM GRB 240821A: optical afterglow discovery
  66. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  67. GRB 240825A: GECAM detection
  68. GRB 240825A: ALMA detection
  69. GRB 240825A: SAO RAS optical observations
  70. GRB 240824A: GIT optical upper limit
  71. GRB 240819A: Swift afterglow confirmation
  72. GRB 240825A: TNG optical photometry and spectroscopy
  73. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  74. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  75. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  76. GRB 240825A: GMG Continued Optical Observation on the Second Night
  77. GRB 240824B: Ondrejov D50 optical limit
  78. GRB 240825A: KAIT optical observations
  79. GRB 240825A: PRIME near-infrared detection
  80. Konus-Wind detection of GRB 240825A (bright/long)
  81. GRB 240825A: Fermi GBM Observation
  82. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  83. GRB 240825A: AKO Optical Follow-Up Observations
  84. GRB 240825A: AstroSat CZTI detection of the long bright burst
  85. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  86. GRB 240825A: Swift/UVOT Detection
  87. GRB 240825A: REM detection of the optical/NIR afterglow
  88. GRB 240825A: VLT/X-shooter redshift
  89. GRB 240825A: SVOM/C-GFT optical observations
  90. GRB 240825A: Montarrenti Observatory optical observations
  91. GRB 240825A: MASTER optical counterpart observation
  92. GRB 240825A: Fermi-LAT detection
  93. GRB 240825A: LCO optical observations
  94. GRB 240824B: KAIT optical upper limit
  95. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  96. GRB 240824B: Fermi GBM Observation
  97. Fermi GRB 240825A: Global MASTER-Net observations report
  98. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  99. GRB 240824B: NOT optical upper limit
  100. GRB 240825A: GMG Optical Observation

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