Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

32511 results found.

  1. GRB 241010A: Swift-BAT refined analysis
  2. GRB 241013B: Fermi GBM Observation
  3. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  4. GRB 241013A: Fermi GBM Observation
  5. GRB 240916A: radio detection with the VLA
  6. GRB241013A: REM observations
  7. GRB 241009A: LCO optical upper limits
  8. GRB 241013B: SVOM/GRM observation
  9. Fermi GRB 241013B: Global MASTER-Net observations report
  10. GRB 241013A: a long GRB detected by INTEGRAL
  11. LIGO/Virgo/KAGRA S241009em: Updated Sky localization
  12. LIGO/Virgo/KAGRA S241011k: Updated Sky localization
  13. LIGO/Virgo/KAGRA S241011k: Identification of a GW compact binary merger candidate
  14. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  15. GRB 241009A: GRANDMA optical upper limits
  16. GRB 241010A: JinShan optical observations and potential host galaxy
  17. GRB 241006A: ATCA Radio Upper Limits
  18. LIGO/Virgo/KAGRA S241007bw: Updated Sky localization
  19. Swift GRB 241010A: Global MASTER-Net observations report
  20. GRB 241010A: J-band observations with WINTER
  21. LIGO/Virgo/KAGRA S241009an: Updated Sky localization
  22. Fermi GRB 241010B: Global MASTER-Net observations report
  23. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  24. GRB 241010A: LCO optical observations
  25. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  26. GRB 241006A: Swift-BAT refined analysis
  27. GRB 241009A: Swift ToO observations
  28. LIGO/Virgo/KAGRA S241009l: Updated Sky localization
  29. LIGO/Virgo/KAGRA S241009em: Identification of a GW compact binary merger candidate
  30. GRB 241008A: Fermi GBM Observation
  31. GRB 241008A: Fermi-LAT detection
  32. GRB 241002B: Swift-XRT afterglow detection
  33. LIGO/Virgo/KAGRA S241009an: Identification of a GW compact binary merger candidate
  34. GRB 241002A: NOT optical upper limits
  35. LIGO/Virgo/KAGRA S241009l: Identification of a GW compact binary merger candidate
  36. Fermi GRB 241008A: Global MASTER-Net observations report
  37. IceCube-241006A: No candidates from the Zwicky Transient Facility
  38. GRB 241006A: GRANDMA optical upper limits
  39. EP240930a / GRB 240930B: CrAO ZTSH optical upper limit
  40. GRB 241002B: PRIME near-infrared detection in 3rd epoch
  41. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  42. GRB 240910A: LBT optical observations
  43. EP trigger ID 01709065118: KAIT confirmation of the stellar flare
  44. GRB 240821A: Host galaxy redshift from VLT/X-shooter
  45. GRB 241006A: PRIME near-infrared upper limits
  46. GRB 241006A: Swift/UVOT Upper Limits
  47. GRB 241006A: SVOM/VT follow-up and optical upper limit
  48. LIGO/Virgo/KAGRA S241007bw: Identification of a GW compact binary merger candidate
  49. GRB 240930B: SVOM/C-GFT optical upper limit
  50. LIGO/Virgo/KAGRA S241006k: Identification of a GW compact binary merger candidate
  51. GRB 240930B / EP 240930a: SVOM/GRM observation
  52. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  53. GRB 241002B: PRIME near-infrared detection in 2nd epoch
  54. GRB 241002B: Fermi GBM Observation
  55. GRB 241002B: Swift-XRT observations
  56. GRB 241002C: SVOM/C-GFT optical upper limit
  57. GRB 241002A: Swift-BAT refined analysis
  58. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  59. GRB 241002B: Swift ToO observations
  60. GRB 241002C: Swift-XRT observations confirm the source to be EI Eri
  61. Konus-Wind detection of GRB 240926A
  62. GRB 241002B: PRIME near-infrared detection
  63. GRB 241002C: Swift ToO observations
  64. Fermi-GBM Sub-Threshold Detection of GRB 241002D
  65. IPN triangulation of GRB 240930B / EP 240930a
  66. GRB 241001A : SVOM/VT optical detection
  67. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  68. GRB 241002B: ULL-ASTRO-MASTER LCOGT 0.4m + QHY600 detection of the GOTO optical counterpart candidate AT 2024xbg / GOTO24gpc
  69. GRB 240930B: CALET Gamma-Ray Burst Monitor detection
  70. GRB 241002C: X-ray afterglow candidate observed by SVOM/MXT
  71. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  72. GRB 241002C : MITSuME Akeno optical upper limits
  73. LIGO/Virgo/KAGRA S240925n: Updated Sky localization
  74. NuEm-240926A: Upper limits from a search for coincident neutrino events in IceCube
  75. GRB241001A: REM optical/NIR upper limits
  76. LIGO/Virgo/KAGRA S241002e: Updated Sky localization
  77. GRB 241002A: Swift/UVOT Upper Limits
  78. EP240930a: Liverpool Telescope observations
  79. GRB 241002A: LCOGT Optical Upper Limits
  80. GRB 241001A: GRANDMA and Kilonova-Catcher optical afterglow detection and upper limits
  81. GRB 241001A: Swift/UVOT Detection
  82. GRB 241001A: VLT/X-shooter redshift
  83. GRB 241002B: GOTO optical counterpart candidate
  84. EP trigger ID 01709064214: GOTO confirms detection as a flare star
  85. GRB 241001A: correction to GCN 37667
  86. GRB 240929A: Liverpool Telescope prompt followup observations
  87. Fermi GRB 241002B: Global MASTER-Net observations report
  88. GRB 241001A: Swift-XRT observations
  89. GRB241001A: optical afterglow candidate
  90. LIGO/Virgo/KAGRA S241002e: Identification of a GW compact binary merger candidate
  91. LIGO/Virgo/KAGRA S240930du: Updated Sky localization
  92. GRB 240930B: Fermi GBM Observation
  93. GRB 241001A: Swift ToO observations
  94. GRB 240930B: GRBAlpha detection
  95. GRB 240929A: GRBAlpha detection
  96. EP240930a : KAIT optical upper limit
  97. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  98. EP240930a: EP-FXT follow-up observation update
  99. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  100. EP240930a: GOTO optical upper limits

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov