Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. 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"

32722 results found.

  1. GRB241001A: optical afterglow candidate
  2. LIGO/Virgo/KAGRA S241002e: Identification of a GW compact binary merger candidate
  3. LIGO/Virgo/KAGRA S240930du: Updated Sky localization
  4. GRB 240930B: Fermi GBM Observation
  5. GRB 241001A: Swift ToO observations
  6. GRB 240930B: GRBAlpha detection
  7. GRB 240929A: GRBAlpha detection
  8. EP240930a : KAIT optical upper limit
  9. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  10. EP240930a: EP-FXT follow-up observation update
  11. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  12. EP240930a: GOTO optical upper limits
  13. GRB 240929A: SVOM/GRM observation
  14. EP EP240930a: Global MASTER-Net observations report
  15. EP240930a: EP-WXT detection of a fast X-ray transient
  16. LIGO/Virgo/KAGRA S240930du: Identification of a GW compact binary merger candidate
  17. IceCube-240929A: Upper limits from a search for additional neutrino events in IceCube
  18. AMON NuEM 240926A: Swift XRT Follow-up
  19. GRB 240929A : Leavitt Observatory optical upper limit
  20. Fermi GRB 240930B: Global MASTER-Net observations report
  21. IPN triangulation of GRB 240926A
  22. GRB 240825A: LBT optical observations
  23. Fermi GRB 240930A: Global MASTER-Net observations report
  24. Fermi Gamma-ray Burst Monitor trigger 749362078/240930172 (GRB 240930A) is not a GRB
  25. LIGO/Virgo/KAGRA S240930aa: Identification of a GW compact binary merger candidate
  26. GRB 240929A long GRB detected by INTEGRAL
  27. Fermi GRB 240929A: Global MASTER-Net observations report
  28. Konus-Wind detection of GRB 240912A
  29. EP trigger ID 01709059262: Lick/Kast spectroscopy with 3 m Shane telescope
  30. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  31. Konus-Wind detection of GRB 240905B
  32. GRB 240529A: FRAM-ORM early optical afterglow observations reveal plateau and rebrightening
  33. EP240919a / GRB 240919A: SVOM/VT upper limit
  34. EP240918b and EP240918c: EP-FXT follow-up observations
  35. LIGO/Virgo/KAGRA S240925n: Updated Sky localization and Source Classification
  36. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  37. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  38. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  39. Konus-Wind detection of GRB 240918B
  40. IPN triangulation of GRB 240918B
  41. GRB 240905B: VZLUSAT-2 detection
  42. LIGO/Virgo/KAGRA S240922df: Updated Sky localization
  43. LIGO/Virgo/KAGRA S240920dw: Updated Sky localization
  44. LIGO/Virgo/KAGRA S240921cw: Updated Sky localization
  45. LIGO/Virgo/KAGRA S240924a: Updated Sky localization
  46. LIGO/Virgo/KAGRA S240920bz: Updated Sky localization and Source Classification
  47. LIGO/Virgo/KAGRA S240923ct: Updated Sky localization and Source Classification
  48. EP trigger ID 01709059262: correction to the observation start time and source localization
  49. LIGO/Virgo/KAGRA S240924a: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  51. LIGO/Virgo S240919bn: GOTO optical upper limits
  52. GRB 240918B: AstroSat CZTI detection
  53. LIGO/Virgo/KAGRA S240922df: Identification of a GW compact binary merger candidate
  54. LIGO/Virgo/KAGRA S240921cw: Identification of a GW compact binary merger candidate
  55. EP240919a: EP-FXT follow-up observation update
  56. EP240913A/GRB 240913C: AbAO optical upper limit
  57. EP240919a / GRB 240919A: Mondy optical upper limit
  58. EP240913a/GRB 240913C: 1.6m Mephisto observations
  59. EP240918a: SVOM/VT upper limit
  60. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  61. EP240919a / GRB 240919A: REM optical and NIR upper limits
  62. EP240919a / GRB 240919A: KAIT optical upper limit
  63. EP240918b and EP240918c: Optical upper limits with Kinder observations
  64. GRB 240414A: further radio observations with the VLA
  65. EP240919a: Optical upper limit with Kinder observations
  66. GRB 240919A / EP240919a: SVOM/GRM observation
  67. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  68. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  69. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  70. EP EP240919a: Global MASTER-Net observations report
  71. GRB 240910A: radio detection with the VLA
  72. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  73. EP240919a: NOT and Gemini optical observations
  74. EP240919a: GOTO optical upper limits
  75. EP240919a: JinShan optical upper limits
  76. EP240919a is likely a GRB event (duplicate submission of 37563)
  77. EP240919a is likely a GRB event
  78. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  79. GRB 240918A and GRB 240918B : INTEGRAL SPI ACS LIGHT CURVE
  80. LIGO/Virgo/KAGRA S240919bn: Updated Sky localization
  81. GRB 240918B: Fermi GBM Detection
  82. LIGO/Virgo/KAGRA S240917cb: Updated Sky localization and EM Bright Classification
  83. LIGO/Virgo/KAGRA S240916ar: Updated Sky localization and EM Bright Classification
  84. EP240918a: EP observation update
  85. GRB 240910A: further Swift observations and confirmation of afterglow
  86. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  87. EP240918a: Swift-XRT observation
  88. Fermi GRB 240918A: Global MASTER-Net observations report
  89. EP EP240918a: Global MASTER-Net observations report
  90. EP240918a: JinShan optical upper limits
  91. EP240918a: YAHPT Optical Upper Limit
  92. EP240918a: Optical upper limits with Kinder observations
  93. EP240918a: GMG Optical Upper Limit
  94. GRB 240916A: GRBAlpha detection
  95. GRB 240914B: GRBAlpha detection
  96. GRB 240916A: NOT optical observation
  97. GRB 240912A: Swift-BAT refined analysis
  98. IPN triangulation of GRB 240913C / EP 240913a
  99. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  100. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova

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