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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"

28296 results found.

  1. IPN triangulation of GRB 240905B (short)
  2. GRB 240825A: 7DT Optical Upper Limit
  3. GRB 240905E: SVOM/VT optical observations
  4. LIGO/Virgo/KAGRA S240910ci: NED Galaxies in the Localization Volume
  5. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  6. LIGO/Virgo/KAGRA S240910ci: Updated Sky localization and EM Bright Classification
  7. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  8. GRB 240910A: SVOM/GRM observation
  9. EP240908a: Mondy and AbAO follow-up observations
  10. EP240908a: Updates on the WXT detection result around the trigger time
  11. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  12. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  13. GRB 240905B: Fermi GBM Observation
  14. Fermi trigger No 747553301: Global MASTER-Net observations report
  15. EP240908a: TRT optical upper limit
  16. EP240908a: EP detection of a fast X-ray transient
  17. LIGO/Virgo/KAGRA S240908dg: Updated Sky localization
  18. LIGO/Virgo/KAGRA S240908bs: Updated Sky localization
  19. LIGO/Virgo/KAGRA S240908dg: Identification of a GW compact binary merger candidate
  20. LIGO/Virgo/KAGRA S240908bs: Identification of a GW compact binary merger candidate
  21. LIGO/Virgo/KAGRA S240907cg: Updated Sky localization
  22. LIGO/Virgo/KAGRA S240907cg: Identification of a GW compact binary merger candidate
  23. GRB 240905E: GIT optical upper limit
  24. GRB 240905B: Swift-XRT observations
  25. GRB 240905E: Gaoyazi/GOT optical upper limits
  26. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  27. GRB 240905E: J-band observations with WINTER
  28. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  29. GRB 240905E: AKO Optical Upper Limit
  30. GRB 240905E: SVOM/C-GFT optical upper limit
  31. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  32. GRB 240905E: NOT optical upper limits
  33. GRB 240905E: REM optical/NIR upper limits
  34. GRB 240902B: AstroSat CZTI detection of a long burst
  35. GRB 240905E: Swift-XRT refined Analysis
  36. GRB 240902A: AstroSat CZTI detection of a long burst
  37. GRB 240905E: LCOGT Optical Upper Limit
  38. GRB 240905E: Swift/UVOT Upper Limits
  39. GRB 240905E: SAO RAS optical upper limit
  40. GRB 240905E: Nanshan/HMT optical upper limit
  41. GRB 240905E: Swift detection of a burst
  42. GRB 240905B: AstroSat CZTI detection and localization
  43. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  45. LIGO/Virgo/KAGRA S240902bq: Updated Sky localization
  46. GRB 240828A: GECAM detection
  47. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  48. GRB 240825A: MeerLICHT afterglow detection
  49. GRB 240828A: SAO RAS AS-500(2) optical observations
  50. GRB 240821A: VLT spectroscopic observations
  51. GRB 240825A: TSHAO Optical Upper Limit
  52. GRB240828B: REM optical/NIR upper limits
  53. GRB 240828B: AbAO optical upper limit
  54. GRB 240825A: SOAR observations
  55. GRB 240828B: Mephisto optical upper limit
  56. GRB 240828B: GRANDMA Optical Upper Limit
  57. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  58. LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
  59. GRB 240829A: Swift-BAT refined analysis
  60. GRB 240825A: Swift-BAT refined analysis
  61. LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
  62. GRB 240828B: J-band upper limit from WINTER
  63. GRB 240828B: GMG Optical Upper Limit
  64. GRB 240828B: SVOM/C-GFT optical upper limit
  65. GRB 240828B: SAO RAS optical upper limit
  66. GRB 240828A: SAO RAS optical observations
  67. Fermi trigger No 746587425: Global MASTER-Net observations report
  68. GRB 240828A: Fermi GBM Observation
  69. GRB 240828A: KAIT Optical Afterglow Candidate
  70. GRB 240825A: SVOM/VT optical detection
  71. GRB 240828A: Swift-XRT afterglow detection
  72. GRB 240825A: further SAO RAS optical observations
  73. GRB 240825A: iTelescope optical observations
  74. GRB 240828B: Swift-XRT afterglow detection
  75. GRB 240829A: Swift detection of a burst
  76. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  77. GRB 240825A: Upper limits from a neutrino search with IceCube
  78. GRB 240821A: PRIME near-infrared observations
  79. GRB 240828B : Detection of a possible very soft X-ray transient by SVOM/ECLAIRs
  80. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  81. GRB 240825A: SAO RAS optical observations
  82. GRB 240824A: GIT optical upper limit
  83. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  84. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  85. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  86. GRB 240825A: GMG Continued Optical Observation on the Second Night
  87. GRB 240825A: PRIME near-infrared detection
  88. GRB 240825A: Fermi GBM Observation
  89. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  90. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  91. GRB 240825A: Swift/UVOT Detection
  92. GRB 240825A: REM detection of the optical/NIR afterglow
  93. GRB 240825A: Swift-XRT refined Analysis
  94. GRB 240825A: VLT/X-shooter redshift
  95. GRB 240825A: Montarrenti Observatory optical observations
  96. GRB 240825A: Enhanced Swift-XRT position
  97. GRB 240825A: LCO optical observations
  98. GRB 240824B: KAIT optical upper limit
  99. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  100. GRB 240824B: Fermi GBM Observation

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