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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"

21093 results found.

  1. IceCube Alert 240419.98: Global MASTER-Net observations report
  2. GRB 240419B: Swift/UVOT Upper Limits
  3. GRB 240419A: Swift/UVOT Upper Limits
  4. GRB 240419B: optical afterglow from the NOT
  5. EP240414a: Near-IR observations with NIRES and WINTER
  6. Swift GRB 240419B: Global MASTER-Net observations report
  7. Swift GRB 240419A: Global MASTER-Net observations report
  8. GRB 240418A: Swift/UVOT Upper Limits
  9. GRB 240419A: REM NIR afterglow detection
  10. GRB 240411B: Swift/UVOT Detection
  11. GRB 240419A: VLT/UVES redshift of z = 5.178
  12. GRB 240419A: VLT optical afterglow detection
  13. Fermi trigger No 735089036: Global MASTER-Net observations report
  14. EP240416a: J-band observations with WINTER
  15. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  16. GRB 240418A: NOT optical upper limits
  17. GRB 240411A: GOTO early optical upper limits
  18. Swift GRB240418.85: Global MASTER-Net observations report
  19. EP240417a: EP-WXT detection of a fast X-ray transient
  20. Fermi GRB 240417A: Global MASTER-Net observations report
  21. LIGO/Virgo/KAGRA S240413p: X-ray upper limits from EP-WXT for the candidate AGN counterpart
  22. EP240414a: GSP detects optical candidate counterpart AT2024gsa
  23. LIGO/Virgo/KAGRA S240413p: DECam GW-MMADS candidates
  24. EP240414a: Pan-STARRS detects re-brightening of the candidate counterpart AT2024gsa
  25. LIGO/Virgo/KAGRA S240413p: historical ATLAS and ZTF observations of the candidate AGN counterpart
  26. LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification
  27. EP240416A: MASTER optical observations
  28. EP240416a: Kinder optical counterpart candidate
  29. EP240416a: EP-WXT detection of a fast X-ray transient
  30. GRB 240414A: AbAO optical upprer limit
  31. GRB 240415A: Swift/UVOT Detection
  32. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  33. GRB 240415A: Earliest optical followup with the Kinder observations
  34. GRB 240415B: Swift ToO observations
  35. GRB 240415B: Swift/BAT-GUANO Correction
  36. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  37. GRB 240415A: OHP/T193 optical observations
  38. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  39. GRB 240415A: SAO RAS optical observations
  40. Fermi GRB 240415A: Global MASTER-Net observations report
  41. GRB 240415A: Mondy optical transient detection
  42. GRB 240414A: Photometric observation from 2.2m CAHA
  43. GRB 240414A: Swift/UVOT Detection
  44. LXT 240402A/GRB 240402B: Swift follow-up observations
  45. GRB 240414A: Mondy optical observations
  46. X-ray transient EP 240414a - GTC spectroscopic observations
  47. GRB 240415A: Prompt Swift-XRT observations
  48. EP 240414a: NOT optical counterpart confirmation
  49. GRB240414A : J-band upper limits from WINTER
  50. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  51. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  52. LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
  53. EP240413A: GOTO optical upper limits
  54. GRB 240414A: Skynet Optical Afterglow Observations
  55. Fermi trigger No 734754044: Global MASTER-Net observations report
  56. Swift GRB 240414A: Global MASTER-Net observations report
  57. EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
  58. Fermi-LAT gamma-ray observations of IceCube-240412A
  59. GRB 240414A : OHP/T193 redshift determination
  60. GRB 240414A : OHP/T193 optical counterpart detection
  61. LIGO/Virgo/KAGRA S240413p: Global MASTER-Net observations report
  62. LIGO/Virgo/KAGRA S240413p: Zwicky Transient Facility observations
  63. EP240408a: GSP optical upper limit
  64. GRB 240411B: CrAO/ZTSh optical observations
  65. GRB 240411B: Kinder observations with Lulin observatory
  66. LIGO/Virgo/Kagra S240413p: NED Galaxies in the Localization Volume
  67. GRB 240411B: HiPERCAM/GTC observation
  68. IceCube Alert 240412.23: Global MASTER-Net observations report
  69. GRB 240411B: 1.3m DFOT Optical observations
  70. GRB 240411B: OHP/T193 optical observations
  71. GRB 240411B: LCO optical afterglow detection
  72. EP240408A: MASTER optical observations
  73. EP240408a: Swift follow-up observation
  74. X-ray transient EP240315a: second epoch e-MERLIN radio observations
  75. EP240408a: EP-WXT detection of a fast X-ray transient
  76. IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
  77. Fermi GRB 240408A: Global MASTER-Net observations report
  78. Fermi GRB 240407A: Global MASTER-Net observations report
  79. Fermi-LAT gamma-ray observations of IceCube-240327B
  80. Fermi-LAT gamma-ray observations of IceCube-240327A
  81. Fermi GRB 240405B: Global MASTER-Net observations report
  82. LXT 240402A/GRB 240402B: GECAM-C refined analysis
  83. Swift satellite resumes pointed science observations
  84. X-ray transient LXT 240402A: WFST optical upper limits​
  85. IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
  86. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  87. LXT 240402A: EP-FXT detection of the X-ray afterglow
  88. Fermi GRB 240404A: Global MASTER-Net observations report
  89. LXT 240402A: MASTER optical observations with AGN in error-box
  90. X-ray transient LXT 240402A: LEIA detection
  91. Fermi trigger No 733808041: Global MASTER-Net observations report
  92. Fermi GRB 240402A: Global MASTER-Net observations report
  93. X-ray transient EP240331a: Kinder optical upper limits
  94. X-ray transient EP240331A: GRANDMA-Kilonova catcher optical upper limit
  95. EP240331A: MASTER optical observations
  96. Transient EP240315a: J-band observations of AT2024eju with WIRC
  97. X-ray transient EP20240331a: MeerLICHT optical upper limits
  98. Integral GRB240401.69: Global MASTER-Net observations report
  99. Fermi trigger No 733366352: Global MASTER-Net observations report
  100. Fermi GRB 240329A: Global MASTER-Net observations report

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