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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"

31727 results found.

  1. GRB 240905E: NOT optical upper limits
  2. GRB 240905E: REM optical/NIR upper limits
  3. GRB 240905E: SVOM/GRM observation
  4. GRB 240905E: LCOGT Optical Upper Limit
  5. GRB 240905E: Swift/UVOT Upper Limits
  6. GRB 240905E: SAO RAS optical upper limit
  7. GRB 240825A: Montarrenti Observatory optical follow-up observations
  8. GRB 240905E: Nanshan/HMT optical upper limit
  9. Swift GRB 240905E: Global MASTER-Net observations report
  10. GRB 240819A: Optical upper limits from TESS
  11. GRB 240905D: AstroSat CZTI detection
  12. GRB 240905A: SVOM/GRM observation
  13. Fermi GRB 240905B: Global MASTER-Net observations report
  14. GRB 240905B: AstroSat CZTI detection and localization
  15. GRB 240825A: ATCA Detection of Radio Counterpart
  16. Swift GRB 240904A: Global MASTER-Net observations report
  17. GRB 240828A: SVOM/GRM observation
  18. Fermi Gamma-ray Burst Monitor trigger 240831A is not a GRB
  19. LIGO/Virgo/KAGRA S240902bq: Updated Sky localization
  20. GRB 240828A: GECAM detection
  21. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  22. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  23. GRB 240825A: MeerLICHT afterglow detection
  24. GRB 240828A: SAO RAS AS-500(2) optical observations
  25. GRB 240821A: VLT spectroscopic observations
  26. GRB 240825A: TSHAO Optical Upper Limit
  27. GRB 240829B: GRBAlpha detection
  28. GRB240828B: REM optical/NIR upper limits
  29. GRB 240828B: AbAO optical upper limit
  30. GRB 240825A: SOAR observations
  31. GRB 240828B: Mephisto optical upper limit
  32. GRB 240828B: GRANDMA Optical Upper Limit
  33. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  34. LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
  35. GRB 240829A: Swift-BAT refined analysis
  36. GRB 240825A: Swift-BAT refined analysis
  37. LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
  38. GRB 240825A: MeerKAT detection
  39. GRB 240828B: J-band upper limit from WINTER
  40. GRB 240828B: GMG Optical Upper Limit
  41. GRB 240828A: KAIT continued optical observations
  42. GRB 240828B: GWAC-F50A optical upper limit
  43. GRB 240828B: SVOM/C-GFT optical upper limit
  44. GRB 240828B: SAO RAS optical upper limit
  45. GRB 240828B: KAIT optical upper limit
  46. GRB 240828A: SAO RAS optical observations
  47. GRB 240828A: Fermi GBM Observation
  48. GRB 240629A: First GRB Detected by BurstCube
  49. GRB 240828A: KAIT Optical Afterglow Candidate
  50. GRB 240825A: SVOM/VT optical detection
  51. GRB 240825A: further SAO RAS optical observations
  52. GRB 240825A: iTelescope optical observations
  53. GRB 240828A: Fermi-LAT detection
  54. GRB 240828A: Tiled Swift observations
  55. GRB 240828A: AstroSat CZTI detection of a long burst
  56. GRB 240825A: Upper limits from a neutrino search with IceCube
  57. GRB 240819A as a likely X-Ray Flash
  58. GRB 240828B: Swift ToO observations
  59. GRB 240821A: PRIME near-infrared observations
  60. GRB 240825A: VLA detection
  61. Fermi GRB 240828A: Global MASTER-Net observations report
  62. SVOM GRB 240821A: optical afterglow discovery
  63. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  64. GRB 240825A: GECAM detection
  65. GRB 240825A: ALMA detection
  66. GRB 240825A: SAO RAS optical observations
  67. GRB 240824A: GIT optical upper limit
  68. GRB 240819A: Swift afterglow confirmation
  69. GRB 240825A: TNG optical photometry and spectroscopy
  70. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  71. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  72. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  73. GRB 240825A: GMG Continued Optical Observation on the Second Night
  74. GRB 240824B: Ondrejov D50 optical limit
  75. GRB 240825A: KAIT optical observations
  76. GRB 240825A: PRIME near-infrared detection
  77. Konus-Wind detection of GRB 240825A (bright/long)
  78. GRB 240825A: Fermi GBM Observation
  79. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  80. GRB 240825A: AKO Optical Follow-Up Observations
  81. GRB 240825A: AstroSat CZTI detection of the long bright burst
  82. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  83. GRB 240825A: Swift/UVOT Detection
  84. GRB 240825A: REM detection of the optical/NIR afterglow
  85. GRB 240825A: VLT/X-shooter redshift
  86. GRB 240825A: SVOM/C-GFT optical observations
  87. GRB 240825A: Montarrenti Observatory optical observations
  88. GRB 240825A: MASTER optical counterpart observation
  89. GRB 240825A: Fermi-LAT detection
  90. GRB 240825A: LCO optical observations
  91. GRB 240824B: KAIT optical upper limit
  92. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  93. GRB 240824B: Fermi GBM Observation
  94. Fermi GRB 240825A: Global MASTER-Net observations report
  95. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  96. GRB 240824B: NOT optical upper limit
  97. GRB 240825A: GMG Optical Observation
  98. Swift GRB 240825A: Global MASTER-Net observations report
  99. GRB 240825A: 1.6m Mephisto multi-band detection
  100. GRB 240825A: AKO Optical Afterglow Detection

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