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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"

32721 results found.

  1. GRB 241016B: Fermi GBM Observations
  2. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  3. GRB 241001A: EP-FXT afterglow detection
  4. GRB 241017A: GROWTH-India Telescope optical upper limit
  5. GRB241017A: TOO Observations by SVOM/MXT
  6. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  7. GRB 241017A: J-band upper limit from WINTER
  8. GRB 241016B: SVOM/GRM observation
  9. GRB 241017A: Swift ToO observations
  10. Fermi GRB 241016B: Global MASTER-Net observations report
  11. Fermi GRB 241016A: Global MASTER-Net observations report
  12. GRB 241010A: Swift-BAT refined analysis
  13. GRB 241013B: Fermi GBM Observation
  14. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  15. GRB 241013A: Fermi GBM Observation
  16. GRB 240916A: radio detection with the VLA
  17. GRB241013A: REM observations
  18. GRB 241009A: LCO optical upper limits
  19. GRB 241013B: SVOM/GRM observation
  20. Fermi GRB 241013B: Global MASTER-Net observations report
  21. GRB 241013A: a long GRB detected by INTEGRAL
  22. LIGO/Virgo/KAGRA S241009em: Updated Sky localization
  23. LIGO/Virgo/KAGRA S241011k: Updated Sky localization
  24. LIGO/Virgo/KAGRA S241011k: Identification of a GW compact binary merger candidate
  25. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  26. GRB 241009A: GRANDMA optical upper limits
  27. GRB 241010A: JinShan optical observations and potential host galaxy
  28. GRB 241006A: ATCA Radio Upper Limits
  29. LIGO/Virgo/KAGRA S241007bw: Updated Sky localization
  30. Swift GRB 241010A: Global MASTER-Net observations report
  31. GRB 241010A: J-band observations with WINTER
  32. LIGO/Virgo/KAGRA S241009an: Updated Sky localization
  33. Fermi GRB 241010B: Global MASTER-Net observations report
  34. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  35. GRB 241010A: LCO optical observations
  36. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  37. GRB 241006A: Swift-BAT refined analysis
  38. GRB 241009A: Swift ToO observations
  39. LIGO/Virgo/KAGRA S241009l: Updated Sky localization
  40. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  41. GRB 241008A: Fermi GBM Observation
  42. GRB 241008A: Fermi-LAT detection
  43. GRB 241002B: Swift-XRT afterglow detection
  44. LIGO/Virgo/KAGRA S241009an: Identification of a GW compact binary merger candidate
  45. GRB 241002A: NOT optical upper limits
  46. LIGO/Virgo/KAGRA S241009l: Identification of a GW compact binary merger candidate
  47. Fermi GRB 241008A: Global MASTER-Net observations report
  48. IceCube-241006A: No candidates from the Zwicky Transient Facility
  49. GRB 241006A: GRANDMA optical upper limits
  50. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  51. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  52. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  53. GRB 240910A: LBT optical observations
  54. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  55. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  56. GRB 241006A: PRIME near-infrared upper limits
  57. GRB 241006A: Swift/UVOT Upper Limits
  58. GRB 241006A: SVOM/VT follow-up and optical upper limit
  59. LIGO/Virgo/KAGRA S241007bw: Identification of a GW compact binary merger candidate
  60. GRB 240930B: SVOM/C-GFT optical upper limit
  61. LIGO/Virgo/KAGRA S241006k: Identification of a GW compact binary merger candidate
  62. GRB 240930B / EP 240930a: SVOM/GRM observation
  63. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  64. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  65. GRB 241002B: Fermi GBM Observation
  66. GRB 241002B: Swift-XRT observations
  67. GRB 241002C: SVOM/C-GFT optical upper limit
  68. GRB 241002A: Swift-BAT refined analysis
  69. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  70. GRB 241002B: Swift ToO observations
  71. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  72. Konus-Wind detection of GRB 240926A
  73. GRB 241002B: PRIME near-infrared detection
  74. GRB 241002C: Swift ToO observations
  75. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  76. IPN triangulation of GRB 240930B / EP 240930a
  77. GRB 241001A : SVOM/VT optical detection
  78. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  79. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  80. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  81. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  82. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  83. GRB 241002C : MITSuME Akeno optical upper limits
  84. LIGO/Virgo/KAGRA S240925n: Updated Sky localization
  85. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  86. GRB241001A: REM optical/NIR upper limits
  87. LIGO/Virgo/KAGRA S241002e: Updated Sky localization
  88. GRB 241002A: Swift/UVOT Upper Limits
  89. EP240930a: Liverpool Telescope observations
  90. GRB 241002A: LCOGT Optical Upper Limits
  91. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  92. GRB 241001A: Swift/UVOT Detection
  93. GRB 241001A: VLT/X-shooter redshift
  94. GRB 241002B: GOTO optical counterpart candidate
  95. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  96. GRB 241001A: correction to GCN 37667
  97. GRB 240929A: Liverpool Telescope prompt followup observations
  98. Fermi GRB 241002B: Global MASTER-Net observations report
  99. GRB 241001A: Swift-XRT observations
  100. GRB241001A: optical afterglow candidate

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