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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"

32736 results found.

  1. GRB 241017A/sb24101702: Mephisto optical upper limit
  2. GRB 241018A: Mondy optical upper limit
  3. GRB 241018A: SVOM/VT further analysis and counterpart confirmed
  4. GRB 241018A: GROWTH-India telescope optical upper limit
  5. GRB241018A: XingLong Optical Upper Limit
  6. GRB 241018A: REM optical/NIR upper limits
  7. GRB 241018A: NOT optical observations
  8. GRB 241017A: SVOM/VT follow-up and optical upper limit
  9. GRB 241018A: SVOM/VT follow-up and optical candidate
  10. GRB 241018A: LCO/0.4m optical upper limits
  11. GRB 241018A: Swift ToO observations
  12. GRB 241006A: VIRT Optical Upper Limit
  13. GRB 240727A: VIRT Optical Upper Limit
  14. GRB 241018A: X-ray afterglow candidate observed by MXT
  15. GRB 241016B: Fermi GBM Observations
  16. GRB241017a: Liverpool Telescope observations of XRT uncatalogued sources
  17. GRB 241001A: EP-FXT afterglow detection
  18. GRB 241017A: GROWTH-India Telescope optical upper limit
  19. GRB241017A: TOO Observations by SVOM/MXT
  20. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  21. GRB 241017A: J-band upper limit from WINTER
  22. GRB 241016B: SVOM/GRM observation
  23. GRB 241017A: Swift ToO observations
  24. Fermi GRB 241016B: Global MASTER-Net observations report
  25. Fermi GRB 241016A: Global MASTER-Net observations report
  26. GRB 241010A: Swift-BAT refined analysis
  27. GRB 241013B: Fermi GBM Observation
  28. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  29. GRB 241013A: Fermi GBM Observation
  30. GRB 240916A: radio detection with the VLA
  31. GRB241013A: REM observations
  32. GRB 241009A: LCO optical upper limits
  33. GRB 241013B: SVOM/GRM observation
  34. Fermi GRB 241013B: Global MASTER-Net observations report
  35. GRB 241013A: a long GRB detected by INTEGRAL
  36. LIGO/Virgo/KAGRA S241009em: Updated Sky localization
  37. LIGO/Virgo/KAGRA S241011k: Updated Sky localization
  38. LIGO/Virgo/KAGRA S241011k: Identification of a GW compact binary merger candidate
  39. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  40. GRB 241009A: GRANDMA optical upper limits
  41. GRB 241010A: JinShan optical observations and potential host galaxy
  42. GRB 241006A: ATCA Radio Upper Limits
  43. LIGO/Virgo/KAGRA S241007bw: Updated Sky localization
  44. Swift GRB 241010A: Global MASTER-Net observations report
  45. GRB 241010A: J-band observations with WINTER
  46. LIGO/Virgo/KAGRA S241009an: Updated Sky localization
  47. Fermi GRB 241010B: Global MASTER-Net observations report
  48. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  49. GRB 241010A: LCO optical observations
  50. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  51. GRB 241006A: Swift-BAT refined analysis
  52. GRB 241009A: Swift ToO observations
  53. LIGO/Virgo/KAGRA S241009l: Updated Sky localization
  54. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  55. GRB 241008A: Fermi GBM Observation
  56. GRB 241008A: Fermi-LAT detection
  57. GRB 241002B: Swift-XRT afterglow detection
  58. LIGO/Virgo/KAGRA S241009an: Identification of a GW compact binary merger candidate
  59. GRB 241002A: NOT optical upper limits
  60. LIGO/Virgo/KAGRA S241009l: Identification of a GW compact binary merger candidate
  61. Fermi GRB 241008A: Global MASTER-Net observations report
  62. IceCube-241006A: No candidates from the Zwicky Transient Facility
  63. GRB 241006A: GRANDMA optical upper limits
  64. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  65. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  66. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  67. GRB 240910A: LBT optical observations
  68. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  69. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  70. GRB 241006A: PRIME near-infrared upper limits
  71. GRB 241006A: Swift/UVOT Upper Limits
  72. GRB 241006A: SVOM/VT follow-up and optical upper limit
  73. LIGO/Virgo/KAGRA S241007bw: Identification of a GW compact binary merger candidate
  74. GRB 240930B: SVOM/C-GFT optical upper limit
  75. LIGO/Virgo/KAGRA S241006k: Identification of a GW compact binary merger candidate
  76. GRB 240930B / EP 240930a: SVOM/GRM observation
  77. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  78. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  79. GRB 241002B: Fermi GBM Observation
  80. GRB 241002B: Swift-XRT observations
  81. GRB 241002C: SVOM/C-GFT optical upper limit
  82. GRB 241002A: Swift-BAT refined analysis
  83. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  84. GRB 241002B: Swift ToO observations
  85. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  86. Konus-Wind detection of GRB 240926A
  87. GRB 241002B: PRIME near-infrared detection
  88. GRB 241002C: Swift ToO observations
  89. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  90. IPN triangulation of GRB 240930B / EP 240930a
  91. GRB 241001A : SVOM/VT optical detection
  92. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  93. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  94. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  95. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  96. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  97. GRB 241002C : MITSuME Akeno optical upper limits
  98. LIGO/Virgo/KAGRA S240925n: Updated Sky localization
  99. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  100. GRB241001A: REM optical/NIR upper limits

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