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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"

45745 results found.

  1. GRB 241104A: Fermi GBM Final Real-time Localization
  2. GRB 241030A: GRBAlpha detection
  3. EP241101a: EP-FXT observations update
  4. EP241103a: GIT optical upper limit
  5. EP241021a: OHP/T193 further optical observations
  6. LIGO/Virgo/KAGRA S241104a: Retraction of GW compact binary merger candidate
  7. Fermi trigger No 752365806: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  9. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  10. EP241103a: GOTO optical upper limit
  11. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  12. EP241101a: Possible detection of an optical counterpart with FTW
  13. EP241103a: Swift XRT detection and improved X-ray position
  14. EP241021a: continued SOAR observations
  15. EP241101a: Optical upper limits with Kinder observations
  16. EP241101a: OHP/T193 optical observations
  17. EP241103a: Gemini optical limits
  18. EP241103a: EP observation update
  19. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  20. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  21. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  22. EP241103a: GSP optical upper limit
  23. EP241103A: LCO optical observations
  24. EP241103a: Global MASTER-Net observations report
  25. EP241103a: an X-ray transient detected by Einstein Probe
  26. GRB 241030A: Rapid release of TESS data.
  27. EP241101a: Global MASTER-Net observations report
  28. GRB 241029A: GRBAlpha detection
  29. EP241101a: BOOTES-7 optical upper limit
  30. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  31. S241102cy: Identification of a GW compact binary merger candidate
  32. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  33. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  34. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  35. GRB241030A: OHP/T193 optical observations
  36. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  37. EP241101a: EP-WXT detection of a fast X-ray transient
  38. Swift GRB 241101A: Global MASTER-Net observations report
  39. GRB 241101A: FRAM-ORM optical limit
  40. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  41. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  42. EP241021a: Upper limit from Konus-Wind observations
  43. GRB 241101A: Swift-BAT refined analysis
  44. GRB 241030A: further SAO RAS optical observations
  45. GRB 241030A: Optical Observations via Virtual Telescope Project
  46. EP241021a: Liverpool Telescope optical follow-up observations
  47. GRB 241030B: Swift-XRT refined Analysis
  48. GRB 241026A: SAO RAS optical observations
  49. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  50. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  51. GRB 241101A: Swift detection of a burst
  52. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  53. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  54. EP241021a: OHP/T193 optical observations
  55. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  56. GRB 241030B: Montarrenti Observatory optical upper limit
  57. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  58. EP241026b: Liverpool Telescope optical follow-up
  59. Fermi trigger No 752083996: Global MASTER-Net observations report
  60. GRB 241030A: SAO RAS optical observations
  61. GRB 241030A: Fermi GBM Observation
  62. EP241021a: AMI-LA radio detection
  63. GRB 241030B : GIT optical upper limits
  64. GRB 241030B: LCOGT Optical Upper Limits
  65. GRB 241030B: Swift-BAT refined analysis
  66. GRB 241030A: Swift-BAT refined analysis
  67. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  68. GRB 241030B: Swift/UVOT Detection
  69. EP EP241030a: Global MASTER-Net observations report
  70. GRB 241029A: LCO optical detection
  71. Fermi trigger No 752006065: Global MASTER-Net observations report
  72. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  73. Swift GRB241030.77: Global MASTER-Net observations report
  74. GRB 241030B: SVOM/GRM observation
  75. GRB 241030B : MITSuME Akeno optical upper limits
  76. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  77. GRB 241030B: SVOM/VT optical afterglow observations
  78. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  79. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  80. GRB241030B: Fermi GBM Observation
  81. GRB 241030B: BTA observations
  82. GRB 241029A: SVOM/VT optical afterglow observations
  83. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  84. GRB 241030B: Enhanced Swift-XRT position
  85. GRB 241030B: optical observations from the INAF Asiago Observatory
  86. EP241021a: Swift-UVOT detection
  87. GRB241030B: GRANDMA/TAROT Upper Limit
  88. GRB 241030A: Swift-XRT refined Analysis
  89. GRB 241030B: SAO RAS optical observations
  90. GRB 241030B: AKO Optical Afterglow Detection
  91. GRB 241030B: Nanshan/HMT optical afterglow detection
  92. GRB 241030B: SVOM/ECLAIRs detection of a burst
  93. GRB 241030B: Prompt enhanced Swift-XRT position
  94. Konus-Wind detection of GRB 241030A
  95. GRB 241030B: Swift detection of a burst
  96. GRB 241030B: Fermi GBM Final Real-time Localization
  97. GRB 241030A: Fermi-LAT detection
  98. GRB 240912A: radio detection with the VLA
  99. Fermi GRB 241030A: Global MASTER-Net observations report
  100. GRB 241030A: AKO Optical Afterglow Detection

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