Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

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"

28284 results found.

  1. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  2. GRB 241115B: Fermi GBM Observation
  3. LIGO/Virgo/KAGRA S241114y: Updated Sky localization
  4. Updates to IceCube realtime alert system for muon tracks
  5. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  6. GRB 241117A: Fermi GBM Detection
  7. IceCube-Cascade 241116A: Upper limits from a search for additional neutrino events in IceCube
  8. LIGO/Virgo/KAGRA S241116cq: Updated Sky localization
  9. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  10. GRB 241115C: Fermi GBM Observation
  11. GRB 241115A: Swift-XRT afterglow detection
  12. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  13. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  14. GRB 241115A: Mephisto upper limits
  15. GRB 241113B: Mephisto upper limits
  16. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  17. GRB 241115D / EP 241115a: SVOM/GRM observation
  18. EP241113a: Swift XRT weak detection
  19. GRB 241115A: Fermi GBM Observation
  20. GRB 241115A: LCOGT Optical Upper Limits
  21. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  22. LIGO/Virgo/KAGRA S241114bi: Updated Sky localization and EM Bright Classification
  23. LIGO/Virgo/KAGRA S241113p: Updated Sky localization
  24. EP241115a: EP detection of a fast X-ray transient
  25. Swift GRB 241115A: Global MASTER-Net observations report
  26. Fermi GRB 241115A: Global MASTER-Net observations report
  27. GRB 241115A: Swift detection of a burst
  28. EP 241113a: LBT possible optical counterpart
  29. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  30. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  31. GRB 241113A: Swift-BAT refined analysis
  32. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  33. GRB 241113A: PRIME near-infrared upper limits
  34. EP241113a: Global MASTER-Net observations report
  35. GRB 241113B: J-band upper limit from WINTER
  36. GRB 241113A: J-band observations with WINTER
  37. EP241113a : J-band observations with WINTER
  38. GRB 241030A: LCO optical observation
  39. GRB 241113B: Swift-XRT observations
  40. IceCube-241113A: Upper limits from a search for additional neutrino events in IceCube
  41. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  42. EP241113b/GRB 241113B: EP detection of GRB 241113B
  43. Fermi-LAT gamma-ray observations of IceCube-241113A
  44. LIGO/Virgo/KAGRA S241114y: Identification of a GW compact binary merger candidate
  45. GRB 241113A: Swift-XRT refined Analysis
  46. GRB 241113A: Swift/UVOT Detection
  47. GRB 241113A: REM detection of the optical/NIR afterglow
  48. LIGO/Virgo/KAGRA S241113p: Identification of a GW compact binary merger candidate
  49. GRB 241113A: LCO optical observations
  50. GRB 241112B: GMG Optical Upper Limit
  51. GRB 241113A: Enhanced Swift-XRT position
  52. GRB241113A: LCOGT (40-cm) optical counterpart detection
  53. GRB 241113A: Swift detection of a burst with an optical counterpart
  54. SVOM/GRM detection of a short burst from SGR 1E1841-045
  55. LIGO/Virgo/KAGRA S241111bn: Updated Sky localization
  56. GRB 241112B: AbAO optical upper limit
  57. GRB 241107A: GROWTH-India telescope optical upper limit
  58. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  59. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  60. GRB 241112B: Swift-XRT afterglow detection
  61. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  62. GRB 241112B: Mephisto optical upper limits
  63. GRB 241112B: GOTO optical upper limits
  64. GRB 241107A: INTEGRAL IBIS localization
  65. LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume
  66. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  67. GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
  68. LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
  69. IPN triangulation of GRB 241107A (short/hard)
  70. GRB 241025C: VZLUSAT-2 detection
  71. GRB 241025A: VZLUSAT-2 detection
  72. GRB 241018A: cubesat Avion detection
  73. GRB 241030B: TESS detection of optical counterpart
  74. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  75. LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
  76. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  77. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  78. Integral GRB241109.89: Global MASTER-Net observations report
  79. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  81. EP241107a: AbAO optical upper limit
  82. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  83. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  84. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  85. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  86. EP241109a: confirmation of a stellar flare by BOOTES-7
  87. GRB 241108A: Swift-XRT observations
  88. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  89. EP241107a: KAIT optical observations
  90. GRB 241030A: TESS observations
  91. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  92. EP241107a: Kinder optical follow-up observations
  93. GRB 241025A: radio detection with the VLA
  94. EP241107a: AKO Optical Afterglow Follow-Up Observations
  95. EP241107a: GSP detects optical counterpart
  96. GRB 241105A: SVOM/GRM observation
  97. EP241107a: OHP/T193 photometric and spectroscopic observations
  98. GRB 241105a: PRIME near-infrared upper limits
  99. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  100. EP241107a: GIT optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov